Biomedical subjects

S C Sikka

Publications and source records attributed to S C Sikka.

At least 19 recordsLinked to original sources

PubMed2001

Role of genitourinary inflammation in infertility: synergistic effect of lipopolysaccharide and interferon-gamma on human spermatozoa.

Pro-inflammatory cytokines are elevated in the semen of patients with genitourinary inflammation (GUI). Whether this increase in cytokines in GUI patients plays any critical role in male factor infertility is not clear. The present study investigated the in vitro effects of two important pro-inflammatory cytokines, lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), on sperm motility, viability, membrane integrity and motion parameters. Washed spermatozoa from healthy donors were incubated with LPS (0.1 mg/mL) or IFN-gamma (0.1 mg/mL) alone or in combination. Sperm motility, viability, membrane integrity and computer-assisted motion were evaluated at various time intervals (0, 30, 60 and 180 min) after treatment. Sperm membrane integrity was analysed using the hypo-osmotic swelling test (HOST). LPS and IFN-gamma individually did not alter sperm viability or motility, but their combination showed a significant time-dependent decrease (p < 0.05) in sperm motility, viability and membrane integrity. Sperm motion parameters (straight-line velocity, curvilinear velocity, mean linearity, or amplitude of lateral head displacement) were not affected by LPS or IFN-gamma at the concentrations used in this study. These data suggest that the combination of LPS and IFN-gamma is detrimental to human spermatozoa and may contribute to male factor infertility in patients with chronic GUI.

Cell Membrane↗

PubMed2001

Relative impact of oxidative stress on male reproductive function.

Impairment of normal spermatogenesis and sperm function are the most common causes of male factor infertility. Abnormal sperm function is difficult to evaluate and treat. There is a lack of understanding of the factors contributing to normal and abnormal sperm function leading to infertility. Many recent studies indicate that oxygen-derived free radicals induce damage to spermatozoa. The excessive generation of these reactive oxygen species (superoxide, hydroxyl, nitric oxide, peroxide, peroxynitrile) by immature and abnormal spermatozoa and by contaminating leukocytes associated with genitourinary tract inflammation have been identified with idiopathic male infertility. Mammalian spermatozoa membranes are rich in polyunsaturated fatty acids. This makes them very susceptible to oxygen-induced damage, which is mediated by lipid peroxidation. In a normal situation, the antioxidant mechanisms present in the reproductive tissues and their secretions are likely to quench these reactive oxygen species (ROS) and protect against oxidative damage to gonadal cells and mature spermatozoa. During chronic disease states, aging, toxin exposure, or genitourinary infection/inflammation, these cellular antioxidant mechanisms downplay and create a situation called oxidative stress. Thus, a balance between ROS generation and antioxidant capacity plays a critical role in the pathophysiology of disease state. Recent efforts towards the development of new reliable assays to evaluate this oxidative stress status have resulted in the establishment of ROS-TAC score. Such assessment of oxidative stress status (OSS) may help in designing newer modes of male factor infertility treatment by suitable antioxidants.

Antioxidants↗

PubMed2000

In vivo gene expression profile analysis of metallothionein in renal cell carcinoma.

The antiapoptotic and mitogenic responses of metallothionein (MT) have been well documented in vitro. While MT protein overexpression, frequently encountered in a number of human primary tumors, has been shown to be correlated with disease progression, little information is available on the in vivo isoform expression of MT. In this study we have demonstrated the occurrence of MT proteins and further defined their differential expression profile in human primary renal cell carcinoma (RCC). Pooled normal human kidney RNA and paired biopsy specimens (tumor and control) obtained from 11 patients diagnosed with RCC with tumor grade ranging from 1-3 and a pathological staging of T2-T3 (N0M0) were used for the study. Samples were analyzed for the presence of MT protein using immunohistochemical (IHC) analysis and for MT isoform-specific mRNA expression by reverse transcriptase polymerase chain reaction. Metallothionein protein assumed both cytoplasmic and nuclear staining in cancer cells and was detected in eight of 11 samples (72%) with polyclonal antibodies. The immunoreactivity of MT protein, but not its cellular localization, in RCC specimens suggests a relationship between and advanced disease. While alterations in the basal level of expression of MT-1E, MT-1F and MT-1X genes remained unchanged, significant up-regulation of MT-2A and down-regulation of MT-1A and MT-1G transcripts was observed in RCC tissue specimens when compared with controls. Intriguingly, the paired RCC biopsy specimens had lower MT-1H transcripts than pooled normal human controls. We here provide the first report of the differential expression of MT isoforms in human RCC and that this data further support the role of MT-2A in tumorigenesis.

Adult↗

PubMed2000

The effect of sildenafil on human sperm motion and function from normal and infertile men.

The aim of this report was to study the effect of sildenafil, a specific type-5 phosphodiesterase inhibitor, on human sperm motility, viability, membrane integrity and sperm penetration assay. Spermatozoa were obtained from normal donors (n = 6) and infertile men (n = 6) were washed using a single Percoll (80%) gradient, suspended in Ham's F-10 medium, and incubated with various doses of sildenafil (125, 250 and 750 ng/ml); pentoxifylline (3 mM) was used as a positive control, and Ham's F-10 was used as a reagent control. Sperm motility, grade, viability, membrane integrity (by hypo-osmotic swelling test), and motion evaluation were carried out at various time intervals. Hamster ova sperm penetration assay (SPA) was used to evaluate overall sperm function. Sildenafil did not affect sperm motility, viability or membrane integrity under these conditions as compared to our Ham's control (P> 0.05). Incubation with pentoxifylline significantly enhanced sperm motility (P < 0.05) and viability without affecting membrane integrity (P < 0.05). Sperm incubated with sildenafil and pentoxifylline from both normal donors and infertile patients demonstrated no significant change in sperm penetration assay from respective controls. In conclusion, sildenafil, at the doses evaluated, did not significantly alter the motility, viability, membrane integrity or sperm penetration characteristics of human spermatozoa from normal donors and infertile patients.

Animals↗

PubMed2000

Adenoviral gene transfer of endothelial nitric oxide synthase (eNOS) to the penis improves age-related erectile dysfunction in the rat.

Nitric oxide (NO) is the principal mediator of penile erection. NO is synthesized by a variety of nitric oxide synthases (NOS). It has been demonstrated that a decrease in NOS activity, as observed in aging, is associated with a diminished erectile response. The objective of this study was to determine if adenoviral-mediated gene transfer of eNOS could reverse age-related erectile dysfunction in the rat. Two groups of animals were transfected with adenoviruses: (1) aged rats (60 weeks) with AdRSVbetagal; and (2) aged rats (60 weeks) with AdRSVeNOS. Five days after transfection, these study animals underwent cavernosal nerve stimulation (CNS) to assess erectile function and their responses were compared with young (20 weeks) control rats. Cross-sections of the rat penises transfected with AdRSVeNOS were examined after trichrome staining. Adenoviral transduction efficiency of beta-galactosidase reporter gene was measured by a galacto-light chemiluminescent reporter gene assay in cavernosal tissues of rats administered AdRSVbetagal. The transgene expression of eNOS was examined by RT-PCR in rats transfected with AdRSVbetagal and AdRSVeNOS. eNOS and iNOS protein levels were measured by Western blot analysis, and cGMP levels were assessed in cavernosal tissue by enzyme immunoassay. Adenoviral expression of the beta-galactosidase reporter gene was observed in cavernosal tissue for up to 30 days, with peak expression registered at 5 days after intracavernosal administration of AdRSVbetagal. Cross-sections of the rat penises transfected with the AdRSVeNOS revealed no pathological (morphological or histological) changes. Five days after administration of AdRSVeNOS, eNOS protein, mRNA and cGMP levels in the corpora cavernosa were significantly increased (P<0. 05), while iNOS protein levels remained unchanged (P>0.05). In conclusion, enhanced expression of eNOS employing an adenoviral vector significantly increased the erectile response to cavernosal nerve stimulation in the aged rat, similar to the response observed in younger rats. These data suggest that in vivo adenoviral gene transfer of eNOS can physiologically improve erectile function in the aged rat.

Adenoviridae↗

PubMed2000

A rat model of Peyronie's disease associated with a decrease in erectile activity and an increase in inducible nitric oxide synthase protein expression.

PURPOSE: Our objective was to assess erectile function in saline-injected, transforming growth factor-beta 1 (TGF-beta1)-injected, and surgical injury rats after six weeks and to determine the role of nitric oxide in this rat model of Peyronie's disease. MATERIALS AND METHODS: Fifty-four adult male CD rats were divided into three groups: 1) saline-injected (0.1 ml.) into the tunica albuginea; 2) TGF-beta1 (0.5 microgram.) injected into the tunica albuginea; and 3) surgical injury to the tunica albuginea. All groups underwent electrical stimulation of the cavernosal nerve and pharmacological stimulation with acetylcholine, an endothelium-dependent vasodilator, after six weeks. In a separate group of animals, aminoguanidine (5 mg./kg. i.v.), a specific iNOS inhibitor, was administered and cavernosal nerve stimulation was performed. Cavernosal tissue was homogenized and constitutive and inducible NOS enzyme activity were measured by L-arginine to L-citrulline conversion in the presence and absence of calcium after 2 days, 3 and 6 weeks in all three groups. Cross-sections of the rat penises were examined using Hart and trichrome stains. RESULTS: Erectile function as measured by cavernosal nerve stimulation and acetylcholine injection was significantly lower (p <0.05) in the TGF-beta1-injected and surgical-injury rats when compared to the saline-injected rats. iNOS inhibition significantly increased (p <0.05) erectile responses to cavernosal nerve stimulation in the rat. iNOS was significantly higher (p <0.05) and constitutive NOS was downregulated (p <0.05) in the corpus cavernosum of the TGF-beta1-injected and surgical-injury rats after 6 weeks. The TGF-beta1-injected and surgical-injury rats exhibited thickening of the tunica albuginea, fragmentation of the elastic fibers, and collagen thickening around the neurovascular bundle. CONCLUSIONS: We have shown that erectile function is significantly lower in the TGF-beta1-injected and surgical-injury rats after 6 weeks at a time when iNOS is upregulated and constitutive NOS is downregulated. Furthermore, iNOS inhibition causes a greater erectile response in the rat, suggesting that iNOS may alter the vascular tone in the penis. These data document a possible mechanism by which some men with Peyronie's disease suffer from erectile dysfunction.

Animals↗

PubMed1999

Characterization of reactive oxygen species induced effects on human spermatozoa movement and energy metabolism.

Reactive oxygen species (ROS) inhibit sperm movement and have been implicated in male infertility. In this study, we determined the effects of specific ROS produced by activated leukocytes on human spermatozoa and investigated their metabolic site of action. We used chemiluminescence and electron paramagnetic resonance (EPR) to characterize the ROS generated by both blood and seminal leukocytes. We also determined the effects of these ROS on sperm energy metabolism using biochemical analyses and flow cytometry. Both blood and seminal leukocytes produced the same characteristic ROS which were determined to be hydrogen peroxide (H2O2) and superoxide radicals (O2*-). EPR using the spin trapping technique indicated that superoxide radical-dependent hydroxyl radicals (HO.) were also generated. ROS generated by PMA-stimulated blood leukocytes (2-5 x 10(6)/ml) caused inhibition of sperm movement in 2 h (p < .01). Using the hypoxanthine/ xanthine oxidase (0.5 U/ml) system to generate ROS, we determined that spermatozoa ATP levels, after ROS treatment, were reduced approximately eight-fold in 30 min (0.10 x 10(10) moles/10(6) sperm cells) compared to control (0.84 X 10(-10) moles/10(6) sperm cells) (p < .01). Sperm ATP reduction paralleled the inhibition of sperm forward progression. Neither superoxide dismutase (100 U/ml) nor dimethyl sulfoxide (100 mM) reversed these effects; however, protection was observed with catalase (4 X 10(3) U/ml). Flow cytometric analyses of sperm treated with various doses of H2O2 (0.3 mM-20.0 mM) showed a dose-dependent decrease in sperm mitochondrial membrane potential (MMP); however, at low concentrations of H2O2, sperm MMP was not significantly inhibited. Also, sperm MMP uncoupling with CCClP had no effect on either sperm ATP levels or forward progression. These results indicate that H2O2 is the toxic ROS produced by activated leukocytes causing the inhibition of both sperm movement and ATP production. O2*- and HO. do not play a significant role in these processes. Low concentrations of H2O2 causing complete inhibition of sperm movement and ATP levels inhibit sperm energy metabolism at a site independent of mitochondrial oxidative phosphorylation.

Adenosine Triphosphate↗

PubMed1999

Stimulation of collagen production in an in vitro model for Peyronie's disease.

AIMS OF THIS STUDY: This study evaluated whether human cavernosal myofibroblasts in cell culture is a viable model for the study of the role of oxygen free radicals in the production of collagen types I and III, as observed in Peyronie's disease. METHOD: Human cavernosal cells in primary culture were incubated with 3H-proline in the absence or presence of (i) glyceraldehyde; (ii) alpha-tocopherol (vitamin E); (iii) a combination of the two; or (iv) gamma interferon alone or in combination with glyceraldehyde. Collagen production was monitored after precipitation by specific monoclonal antibody and quantitated using a scintillation counter. RESULTS: Collagen type III was stimulated to higher than baseline values after doses of 10 and 100 microM glyceraldehyde was added and showed suppression of stimulation with incorporation of alpha-tocopherol. There was a 40% increase in collagen type III production as compared to baseline values in glyceraldehyde-treated cells. Collagen type I showed no consistent stimulation or suppression. In glyceraldehyde-stimulated transformed caveronsal cells, alpha-tocopherol treatment caused a 10-60% decrease in collagen type I and III production. With the addition of 100,000 IU/ml gamma interferon, a significant reduction of both collagen types I and III was observed. CONCLUSIONS: The generation of oxygen radicals is associated with the stimulation of collagen production in cavernosal cells. Transformed fibroblasts from cavernosal cells in culture can be utilized to explore possible etiologies of Peyronie's disease and to further evaluate potential medical therapies for this pathological condition.

Cells, Cultured↗

PubMed1999

Potentiation of erectile response and cAMP accumulation by combination of prostaglandin E1 and rolipram, a selective inhibitor of the type 4 phosphodiesterase (PDE 4).

PURPOSE: Phosphodiesterases (PDEs) are an important component of the signal transduction pathway during the erectile response. To determine the PDE isoforms in the corpora cavernosa in the cat and to establish the functional presence of PDE 4 in human cavernosal tissue, the erectile response to intracavernosal phosphodiesterase (PDE) inhibitors alone and the combination of PDE inhibitors and prostaglandin E1 (PGE1) was evaluated in the anesthetized cat. The in vitro formation of cAMP and cGMP in human cavernosal smooth muscle cells (HCSMCs) treated with PGE1 and rolipram in primary culture was also measured. MATERIALS AND METHODS: In pentobarbital-anesthetized cats, increases in intracavernosal pressure, penile length, and duration of erectile response were determined after intracavernosal injections of (i) the type 3 cAMP-specific, cGMP-inhibitable PDE inhibitor, milrinone, (ii) the type 4 cAMP-specific PDE inhibitor, rolipram, (iii) the type 5 cGMP-specific PDE inhibitor, zaprinast, and (iv) the combination of rolipram and PGE1. Systemic arterial pressure was concurrently assessed in these experiments. All responses to PDE inhibitors were compared with a control triple-drug combination comprised of papaverine (1.65 mg.), PGE1 (0.5 microg.), and phentolamine (25 microg.). HCSMCs were incubated with PGE1 (3 microM) and rolipram (10 microM) individually or in combination up to 2 hours at 37C. The intracellular cAMP and cGMP was extracted by cold absolute ethanol and measured (pmol./10(6) cells) by a commercially available EIA kit. RESULTS: Milrinone (3 to 100 microg.), rolipram (3 to 100 microg.), and zaprinast (3 to 100 microg.) induced dose-dependent increases in intracavernosal pressure and penile length (p <0.05) when administered intracavernosally. The maximum increase in cavernosal pressure in response to zaprinast was associated with no significant change in systemic arterial pressure. When rolipram was combined with PGE1 (0.1 microg.), the increases in intracavernosal pressure and the duration of erectile response were significantly higher (p <0.05) and longer (p <0.05) than those observed when rolipram alone was injected intracavernosally. PGE1 (3 microM) and rolipram (10 microM) produced significant increases (p <0.05) in the accumulation of intracellular cAMP levels in HCSMCs in primary culture above those of the baseline values while intracellular levels of cGMP did not change. CONCLUSIONS: PDE inhibitors administered intracavernosally caused dose-dependent increases in cavernosal pressure in the cat. When a specific cAMP PDE inhibitor was combined with PGE1, the erectile response was enhanced and intracellular levels of cAMP were increased in HCSMCs in primary culture. These data suggest further exploration of the combination of various PDE inhibitors and PGE1 in the pharmacologic treatment of erectile dysfunction and provide functional evidence for the presence of PDE 4 isoenzyme in human penile cavernosal cells.

Alprostadil↗

PubMed1998

Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure.

The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 micromol/kg CdCl2). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 micromol/kg ZnAc), given 24 h prior to 20 micromol/kg CdCl2 administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible reproductive organs.

Animals↗

PubMed1998

Effects of alprostadil and prazosin on motility, viability and membrane integrity of human sperm.

PURPOSE: We evaluated the effects of alprostadil, prazosin hydrochloride, and alprostadil/prazosin hydrochloride, agents used in the clinical treatment of male erectile dysfunction, on the motility, viability and membrane integrity of human sperm. MATERIALS AND METHODS: Ten healthy volunteers provided semen samples that were incubated with 0.4 mg./ml. alprostadil, 0.1 and 0.2 mg./ml. prazosin hydrochloride and 0.4 mg./ml. alprostadil plus 0.1 mg./ml. prazosin hydrochloride for 2 hours. Control incubations included polyethylene glycol 1450, the formulation vehicle for the clinical use of alprostadil and prazosin, and Ham's F-10 buffer. Serial evaluations of percent sperm motility, percent viability, membrane function (by hypo-osmotic swelling test) and several computer generated measurements of sperm motion, including straight line velocity, curvilinear velocity, linearity and amplitude of lateral head displacement, were made. RESULTS: None of the agents had a significant impact on the percentage of motile or viable sperm or on sperm membrane function. Incubation with 0.2 mg./ml. prazosin reduced straight line velocity and curvilinear velocity significantly compared with the other agents. These changes were most likely a direct result of the viscosity of the 0.2 mg./ml. prazosin solution and not a cellular or metabolic effect on the sperm. CONCLUSIONS: Alprostadil and prazosin hydrochloride at doses used in transurethral therapy for erectile dysfunction have no effect on the motility, viability and membrane integrity of human sperm.

Adrenergic alpha-Antagonists↗

PubMed1997

Effect of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on human sperm motility, viability and motion parameters.

Male genital tract infections and non-specific inflammatory conditions may be associated with unexplained infertility. Previous studies have shown the presence of cytokines such as tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in the semen of infertile men. However, the mechanism of effect of these cytokines on human sperm function is still controversial. The present study was undertaken to investigate the in-vitro effects of TNF-alpha and IFN-gamma on human sperm motion, viability and the hypoosmotic swelling test (HOST). Washed spermatozoa from normal volunteers (n = 9) were incubated in the presence/absence of TNF-alpha (1 microgram/mL) plus IFN-gamma (0.1 microgram/mL). Sperm motility, viability, HOST, and video sequences were recorded at different time intervals (0, 30, 60 and 180 min). Sperm motion parameters were analysed using computer-assisted semen analysis. There was a time-dependent negative effect of TNF-alpha plus IFN-gamma on sperm motility, viability, HOST, and lateral-head displacement (ALH). The maximum decrease was observed between 60 and 180 min for sperm motility (50.8 +/- 5.6%), viability (52.8 +/- 4.0%), HOST (38 +/- 2%) and ALH (4.7 +/- 0.1 microns) compared to control samples (62.2 +/- 2.8, 62.4 +/- 2.9, 58 +/- 4, and 5.3 +/- 0.4, respectively; All p < 0.05). There was no significant effect on sperm straight-line velocity and mean linearity when compared to control. These data suggest that the common inflammatory cytokines TNF-alpha plus IFN-gamma have only partial detrimental effects on sperm motility, viability, membrane integrity and lateral head displacement, which may contribute to the poor fertilizing potential of human spermatozoa during inflammatory conditions.

Cell Membrane↗

PubMed1996

Oxidative stress and role of antioxidants in normal and abnormal sperm function.

Defective sperm function is the most common cause of infertility, and until recently, it was difficult to evaluate and treat. Part of this difficulty was due to our incomplete understanding of the factors contributing to normal and abnormal sperm function leading to male infertility. Mammalian spermatozoa membranes are rich in high unsaturated fatty acids and are sensitive to oxygen induced damage mediated by lipid peroxidation. Limited endogenous mechanisms exist to reverse these damages. The excessive generation of reactive oxygen species (ROS) by abnormal spermatozoa and by contaminating leukocytes (leukocytospermia) has been identified as one of the few defined etiologies for male infertility. In a normal situation, the seminal plasma contains antioxidant mechanisms which are likely to quench these ROS and protect against any likely damage to spermatozoa. However, during genitourinary infection/inflammation these antioxidant mechanisms may downplay and create a situation called oxidative stress. In addition, aging and environmental toxicants are also likely to further induce this oxidative stress. Assessment of such oxidative stress status (OSS) may help in the medical treatment of this male factor infertility by suitable antioxidants.

Antioxidants↗

PubMed1995

Penile intracavernosal substance abuse.

A complete workup for a 36-year-old man with unexplained inguinal adenopathy and an indurated, enlarged penis and scrotum included urine cultures for bacteria, fungi, and acid-fast bacilli; scrotal ultrasound; computed tomography of the abdomen and groin; a retrograde urethrogram; a cystogram; duplex penile Doppler blood flow studies; and a surgical inguinal lymph node dissection. Pathologic examination of the excised lymph node revealed lipoid granulomatous lymphadenitis. After receiving definitive treatment for a psychotic condition, the patient acknowledged a 2-year history of intracavernosal injection of gelatinous vitamin E.

Adult↗

PubMed1995

Oxidative stress and interleukins in seminal plasma during leukocytospermia.

OBJECTIVE: To quantify the levels of reactive oxygen species, superoxide dismutase (SOD), and interleukins (IL) 2 and 8 in seminal plasma of infertile patients as well as to examine the possible relationship between oxidative stress and proinflammatory cytokines. DESIGN: Semen collected from normal fertile donors, infertile men without symptoms of genitourinary (GU) inflammation, and infertile men with symptoms of infection-inflammation of the GU tract was evaluated for the levels of granulocyte elastase, reactive oxygen species, SOD, IL-2, and IL-8. Any correlation between the levels of reactive oxygen species and other parameters in these population was analyzed statistically. RESULTS: Significantly high levels of granulocyte elastase (18.32 +/- 1.52 U/L), reactive oxygen species (6 x 10(5) cpm), IL-8 (3.7 +/- 0.10 microgram/L), and IL-2 (18.32 +/- 1.47 ng/L) were observed in semen of infertile patients with leukocytospermia compared with the other two groups. In leukocytospermic samples, the activity of SOD was significantly lower (624.89 +/- 41.16 NU/mL) compared with nonleukocytospermic samples (787.85 +/- 24.26 NU/mL) or fertile donors (816.29 +/- 50.16 NU/mL). A significant positive correlation was observed between the levels of reactive oxygen species and IL-8. CONCLUSIONS: These findings suggest that increased oxidative stress observed during leukocytospermia may modulate the level of proinflammatory cytokines. The increased oxidative stress may be due to a defect in the reactive oxygen species scavenging system.

Humans↗

PubMed1994

Effect of sodium nitroprusside on sperm motility, viability, and lipid peroxidation.

OBJECTIVE: To analyze the effect of sodium nitroprusside, a nitric oxide releaser, on sperm motion and lipid peroxidation-induced membrane damage in cryopreserved human sperm. DESIGN: Post-thaw, cryopreserved, human sperm samples were washed and divided into three aliquots. Each aliquot was incubated with either 0, 50, or 100 nM sodium nitroprusside. INTERVENTIONS: Samples were analyzed for lipid peroxidation (measured by malonaldehyde-thiobarbituric acid reactivity) at 3 hours post-thaw. MAIN OUTCOME MEASURES: Percent viability and motion parameters were assessed at 0, 10, and 30 minutes and 2, 3, 5, and 6 hours post-thaw. RESULTS: All results represent a mean +/- SEM, n = 10. Lipid peroxidation in samples incubated with 50 nM sodium nitroprusside (15.1 +/- 2.1 nM malonaldehyde/10(8) sperm) or 100 nM sodium nitroprusside (13.2 +/- 2.1 nM malonaldehyde/10(8) sperm) was significantly lower than in controls (22.7 +/- 3.1 nM malonaldehyde/10(8) sperm). Percent viability was significantly reduced from 0 minutes (60.6% +/- 3.5%) to 6 hours post-thaw in controls (38.0% +/- 5.1%) but not in 50 nM (46.8% +/- 10.4%) or 100 nM (48.8% +/- 6.5%) sodium nitroprusside-treated samples. Compared with controls (18.3% +/- 3.4%), maintenance of percent motility at 3 hours post-thaw was significantly improved in 50 nM (24.5% +/- 2.9%) and in 100 nM (26.3% +/- 3.2%) sodium nitroprusside-treated samples. Straight line velocity maintenance was significantly improved in 50 nM (37.3 +/- 1.3) and in 100 nM (37.0 +/- 1) sodium nitroprusside-treated samples as compared with controls (30.5 +/- 1.7). Significant improvements in curvilinear velocity maintenance compared with controls (56.3 +/- 2.9) also were observed in 50 nM (65.9 +/- 2.1) and 100 nM (72.1 +/- 4.1) sodium nitroprusside-treated samples. Significant differences in the motion parameters of sodium nitroprusside-treated samples were maintained at 5 and 6 hours post-thaw in comparison to controls. CONCLUSION: These results suggest that sodium nitroprusside is beneficial to the maintenance of post-thaw sperm motion and viability for up to 6 hours and that reduction of lipid peroxidative damage to sperm membranes may be the mechanism for these benefits.

Cell Survival↗

PubMed1994

Nitric oxide mediates penile erection in cats.

The present study was undertaken to investigate the in vivo effects of nitric oxide (NO) mediating agents injected intracavernosally on penile erection in cats. All NO donors increased the cavernosal pressure and penile length in a dose-dependent manner. The maximal effects on cavernosal pressure and penile length induced by s-nitrosocysteine (NO-CYS) and s-nitroso-n-acetylpenicillamine (SNAP), respectively, were 8-fold and 5-fold increases in pressure, and 45% and 34% increases in length when compared with baseline values. These changes were comparable to that caused by the control drug combination (papaverine, phentolamine and prostaglandin E1). The effects of acetylcholine (ACh) and substance P on cavernosal pressure and penile length were less than those obtained with the control drug combination, NO-CYS (p < 0.01), or SNAP (p < 0.05). N omega-nitro-l-arginine-methyl-ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, significantly decreased the effects of NO-CYS, ACh and substance P on penile erection. This in vivo study with NO donors and an NOS inhibitor suggests that NO is a mediator of penile erection in cats.

Acetylcholine↗

PubMed1994

Post-thaw sperm motility, cAMP concentration and membrane lipid peroxidation after stimulation with pentoxifylline and platelet-activating factor.

Earlier studies have demonstrated that pentoxifylline (PTX) and platelet-activating factor (PAF) can significantly improve the motion parameters of post-thaw human spermatozoa. This study has investigated the effects of PAF, PTX and their combination on cyclic adenosine monophosphate (cAMP) concentrations and membrane lipid peroxidation (LPO) in post-thaw human spermatozoa. Washed spermatozoa from normal volunteers (n = 10) were cryopreserved in Test-yolk buffer using a standard protocol. After 2 weeks the sperm samples were thawed, washed and incubated with either 1 microM PAF, 3 mM PTX or 0.5 microM PAF plus 1.5 mM PTX. Video sequences were recorded at 0, 30, 60, and 120 min for analysis of sperm motion parameters using the Cell Track Sperm Analysis System. Concentrations of cAMP were assessed by radioimmunoassay, and LPO levels were measured by malondialdehyde-thiobarbituric acid reactivity. Our studies indicate a time-course stimulatory effect with overall maximal stimulation observed in samples treated with the combination of PAF and PTX. The maximal stimulation of percentage motility compared to control was observed at 60 min in samples treated with PAF, PTX, or PAF plus PTX. PAF plus PTX stimulated straight-line velocity (VSL), curvilinear velocity (VCL) and lateral head displacement (ALH) after 30 min incubation. The primary effect of PAF was observed on VSL, while the main effect of PTX was on VCL. cAMP concentrations were 3-fold higher than controls in samples treated with PTX or PAF plus PTX. cAMP concentrations in PAF-treated samples did not differ significantly from controls. No significant differences were observed between any groups for LPO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗