Biomedical subjects

M M Misro

Publications and source records attributed to M M Misro.

At least 19 recordsLinked to original sources

PubMed2006

H2O2 at physiological concentrations modulates Leydig cell function inducing oxidative stress and apoptosis.

H(2)O(2) is one of the active reactive oxygen species secreted by macrophages that are seen closely aligned with Leydig cells in the testicular interstitium. The present study was initiated to investigate the role of H(2)O(2) on Leydig cell function in vitro at physiological concentrations. Significant decrease in both testosterone production (p < 0.05) and 3 beta-hydroxysteroid dehydrogenase activity (p < 0.05) in adult Leydig cells were observed even with H(2)O(2) at low concentrations (30 - 50 microM). H(2)O(2) exposure increased oxidative stress in Leydig cells with the rise in lipid peroxidation and fall in the activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT) & glutathione-s-transferase (GST). There was also a marginal increase (approximately 8%) in cell apoptosis accompanied by rise in FasL expression and caspase-3 activation. The above findings indicate that H(2)O(2) as a bio-molecule modulates Leydig cell function at or below physiological concentrations through a variety of actions like decrease in steroidogenic enzyme activity and increase in oxidative stress and apoptosis.

3-Hydroxysteroid Dehydrogenases↗

PubMed2006

Estradiol treatment induces testicular oxidative stress and germ cell apoptosis in rats.

In order to understand the pathogenesis of estradiol induced effects in the seminiferous epithelium, studies were undertaken in adult rats with estradiol-3-benzoate administered for different durations. After 30 d of treatment, a significant rise in lipid peroxidation with concomitant fall in the activities of superoxide dismutase and catalase was observed. Both, serum and intra-testicular testosterone levels were found severely depleted. Seminiferous epithelium was devoid of elongated spermatids and spermatozoa by 30 d of treatment. Number of spermatocytes and round spermatids were significantly (p < 0.001) reduced. Flowcytometric analysis confirmed a drastic reduction of the haploid cell population (1c peak). Beginning from day 10 of treatment, there was a consistent rise in the number of pyknotic/apoptotic germ cells in the seminiferous epithelium. A gradual increase in Bax protein expression was observed with the duration of treatment. The shift in Bax immunostaining from the cytoplasm and nucleus of germ cells (at 10 d of treatment) to only nuclei of cells by 30 d of treatment was also noticed. By this time testicular tissue showed three-fold increase in caspase-8 enzyme activity. Viable testicular cells isolated in vitro decreased drastically subsequent to different periods of estradiol treatment. The above findings substantiate the fact that the testicular pathogenesis of estradiol benzoate treatment may be primarily because of altered reproductive hormone levels and high oxidative stress leading to germ cell apoptosis and subsequent germ cell loss in the seminiferous epithelium.

Animals↗

PubMed2005

Apoptosis and cell removal in the cryptorchid rat testis.

In order to determine that apoptosis is responsible for large-scale germ cell elimination, we analyzed cells from cryptorchid testes both in histological sections and among those isolated in vitro. Apoptotic testicular cells during 3 to 7 days were only 8 to 30%, reaching a maximum of 80% by the end of 15 days of cryptorchidism. A similar trend was also observed with the number of dead cells. The process of large-scale germ cell removal in the initial stages was facilitated by the formation of multinucleated giant cells, which stained negative for apoptosis. Increase in oxidative stress and decrease in intratesticular testosterone was also observed. The above findings indicate that large-scale germ cell removal, at least during initial stages of cryptorchidism is not solely as a result of apoptosis. Declined intra testicular testosterone, elevated temperature and high oxidative stress following cryptorchidism probably affect cell viability and trigger a fast pace cell removal through giant cell formation.

Animals↗

PubMed2005

Germ cell death and their removal during initial stages of testicular ischemia and cryptorchidism: a comparative analysis.

Germ cell death and their removal from the seminiferous epithelium are common in the affected testis in conditions of unilateral ischemia or cryptorchidism; the similarities and differences, however, have not been studied between these two conditions. The present study was designed to examine the severity of the effect on testicular germ cells during the initial stages of both ischemia and cryptorchidism, which have significant implications on the restoration of fertility following surgical repair. Complete absence of spermatids was observed following 12 hr of ischemia as compared to 7 days of cryptorchidism. Germ cell removal in either case was in the direction of lumen to basement membrane leaving only a single layer of cells by 24 hr of unilateral ischemia as compared to 15 days of cryptorchidism. Levels of intratesticular testosterone was found lower in cryptorchidism (7 days) but not in ischemia till 24 hrs. Giant cells frequently observed in cryptorchid testis were absent in the ischemic seminiferous epithelium. There was a gradual increase in the number of apoptotic and non-viable cells; the latter was more than 95% by 24 hr of ischemia. In contrast, approximately 85% testicular cells were nonviable till 15 days of cryptorchidism. The 1c peak representing the population of haploid cells was significantly reduced in cryptorchidism (7 days), while the peak was completely abolished by 24 hr of ischemia. Rise in the levels of oxidative stress in the affected testis was observed identically during the initial stages. These findings indicate that coupled with the rise in tissue oxidative stress, the number of apoptotic/nonviable germ cells was alarmingly high (> 80%) by 15 days of cryptochidism or 24 hr of ischemia. Restoration of complete spermatogenesis following surgical repair may not be possible in such cases because of these acute adverse effects.

Animals↗

PubMed2004

Use of hydrogen peroxide to assess the sperm susceptibility to oxidative stress in subjects presenting a normal semen profile.

Human sperm susceptibility to oxidative stress is vital as it affects various characteristics of sperm function. In the present study, we report a simple, sensitive and quick method of assessing the capacity of the sperms to withstand increased oxidative stress. The basis for the test was derived from the fact that human sperms suspended in Ham's F-10 medium tend to lose the forward progressive motility when co-incubated with H(2)O(2) (600 microm). Replacement of the medium with seminal plasma (1: 1) was able to reduce the loss of sperm motility (40%). Retention of sperm motility in semen (0-30%) following 10 min of H(2)O(2) (600 microm) exposure was taken as the criteria for delineating the quality of sperm as poor, moderate, good and excellent types. The protocol was tested in 87 subjects presenting a normal semen profile. On the basis of this test, 44% of the semen samples were classified as poor and the rest as moderate, good or excellent. Lipid peroxidation was found higher in the sperms from the 'poor' category. Activities of superoxide dismutase and catalase were also significantly elevated in the seminal plasma of these subjects as compared with combined categories of good or excellent. The test described here can be used routinely in laboratory investigations to assess sperm susceptibility to oxidative stress in subjects presenting a normal semen profile.

Adult↗

PubMed2003

Protective role of cyclosporine in experimental unilateral blunt testicular trauma: evaluation by 31P MR spectroscopy.

Magnetic resonance (MR) imaging is a useful tool to study the anatomy of the testis while 31P magnetic resonance spectroscopy (MRS) provides a non-invasive alternative method to demonstrate the metabolic status of testes. This study was designed to test whether the protective role of cyclosporine in experimental unilateral blunt testicular trauma (UBTT) could be assessed by 31P MRS. Male Wistar rats (n = 30) aged 20 days were randomised into group I (sham surgery), group II (UBTT) and group III (UBTT and cyclosporine for 7 days). Contralateral testicles of 5 rats from each group was evaluated by 31P MRS at 30 and 60 days of age and phosphomonoesters (PM), phosphodiesters (PD), and adenosine triphosphate (ATP) levels were measured. At 60 days of age the PM/ATP ratio was 0.32+/-0.08 in group I whereas it was 0.68+/-0.31 in the group II (p<0.05). Group III rats showed PM, PD and PM/ATP ratios similar to the controls. In conclusion, it is observed that UBTT causes contralateral testicular damage which could be prevented by short-term cyclosporine treatment and 31P MRS is an excellent modality for such an evaluation.

Animals↗

PubMed2003

A short-term evaluation of semen and accessory sex gland function in phase III trial subjects receiving intravasal contraceptive RISUG.

Following the intravasal injection of a new male contraceptive RISUG (reversible inhibition of sperm under guidance) in volunteers, routine semen analysis, semen biochemistry and germ cell morphology were evaluated in comparison with the corresponding preinjection samples for a maximum period of 6 months. Sperm counts in all 25 subjects before injection varied from 45 to 120 x 10(6)/ml. Out of 25 subjects, 6 became azoospermic after 1 month, 15 after 2 months, 3 after 3 months and 1 after 4 months of contraceptive injection. The mean volume of the ejaculates was found to be less as compared to preinjection samples. Occasional sperm or sperm heads and immature germ cells were identified in only a few postinjected subjects. However, no pregnancy was reported in these subjects during the study period. Abnormal morphology found in most of the sperm, but not in the accompanying immature germ cells, may be due to a charge-related effect on the former but not on the latter cells. Neutral alpha-glucosidase, the biochemical marker for epididymis, was estimated to be significantly lower in the seminal plasma of all the postinjected subjects. On the other hand, acid phosphatase activity and fructose levels in the seminal plasma were found to be in the normal range. Based on the above findings, it is concluded that at least for the present study period, RISUG, a new male contraceptive, is effective as a partially occluding agent in the vas deferens.

Acid Phosphatase↗

PubMed2003

Prepubertal human chorionic gonadotropin injection affects postpubertal germ cell maturation and androgen production in rat testis.

OBJECTIVES: To examine the effects of varying doses of prepubertal human chorionic gonadotropin (hCG) administration on postpubertal germ cell status and androgen status in rats. The long-term effects of prepubertal hCG administration on postpubertal testicular function are still debated. METHODS: Forty male prepubertal Wistar rats, aged 20 days, were divided into four equal groups. Group 1 served as the controls. Each rat in groups 2, 3, and 4 received subcutaneous hCG injections of 5 IU, 10 IU, and 50 IU, respectively, on days 20 and 30 of life. Serum testosterone levels were estimated on days 33 and 70. On day 70, the left testis of each rat was harvested for DNA flow cytometric analysis. RESULTS: The testosterone levels on day 33 progressively increased from groups 1 through 4, and the difference between any two groups was statistically significant. In contrast, the testosterone levels on day 70 were greatest in group 1 and progressively decreased in groups 2 through 4, with the lowest value in group 4. On day 70, only group 4 rats had a significantly reduced haploid cell population compared with all other groups. CONCLUSIONS: Prepubertal hCG administration adversely affects testosterone levels, and a high dose of hCG has adverse effects on the germ cell haploid cell population. A critical reevaluation of the use of hCG is required in prepubertal boys, especially with respect to the dosage.

Androgens↗

PubMed2003

Simultaneous increase in germ cell apoptosis and oxidative stress under acute unilateral testicular ischaemia in rats.

Ischaemia induced germ cell apoptosis in rat testis was studied in detail to find out (i) spermatogenic stage or seminiferous epithelium region specific involvement of germ cells in apoptosis, (ii) preferential specificity of a particular germ cell type to become apoptotic and (iii) the ratio of live and dead testicular cells isolated in vitro after various period of ischaemic induction. Cell apoptosis, as observed in histological sections increased from 1 to 24 h of ischaemia. Apoptosis was not restricted to any specific germ cell type but was observed simultaneously in all the cell types in the initial hours (1-6 h) of ischaemia. No spermatogenic stage specific preference in apoptotic induction was also observed. However, as the duration of ischaemia progressed, the cell types observed to be most affected in number and morphology were the spermatids followed by spermatocytes. Centrally located tubules of testis were affected first than those located in the periphery. Overexpression of Bax staining was limited to few germ cell nuclei only. More than 95% of the germ cells in the control testis that earlier showed trypan blue dye exclusion were found stained after 12 h of ischaemia. Starting from early hours (1 h), lipid peroxidation rose proportionally with the duration of ischaemia while superoxide dismutase (SOD) and catalase activities were found decreased. Significant (p < 0.05) increase in the activities of glutathion-s-transferase and levels of hydrogen peroxide were observed after 6 h of ischaemia. These findings indicate that the physiological processes of oxidative stress have a direct linkage to the extent of germ cell apoptosis in the seminiferous epithelium.

Acute Disease↗

PubMed2003

Evaluation of trend in semen analysis for 11 years in subjects attending a fertility clinic in India.

AIM: The data on semen analysis of subjects attending the Fertility Clinic at NIHFW (National Institute of Health and Family Welfare) Munirka, New Delhi for the last 11 years were analyzed to verify the claims and speculations on declining sperm counts in men. METHODS: Approximately 10 % of the records every year starting from 1990 to 2000 (numbering 1176 in total) were randomly selected for analysis. Subjects with azoospermia or severe oligozoospermia were excluded from analysis. RESULTS: The average age of the men attending the infertility clinic was 31.2 years. The average semen volume and sperm count were found to be (2.6+/-0.1) mL and (60.6+/-0.9)X10(6)/mL, respectively. No significant decline in sperm counts was observed in any year during the entire study period. Only 1.8 % of the total number of sperm counts in the random sampling were less then 20 X10(6)/mL. On the basis of WHO criteria on motility, the total percentage of non-progressive and non-motile sperm in the ejaculate was higher (63 %) as compared to the combined categories of slow and rapid linear progressive. CONCLUSION: The present study has confirmed similar findings from other different countries that declining sperm counts in humans is not a global phenomenon.

Adult↗

PubMed2002

Assessment of human sperm function after hydrogen peroxide exposure. development of a vaginal contraceptive.

The reactive oxygen species (ROS) that is most damaging to human spermatozoa is hydrogen peroxide. Using an artificial medium Ham's F-10, we have evaluated the effect of different concentrations of hydrogen peroxide (H(2)O(2)) on various sperm function characteristics to develop a water-based vaginal contraceptive. H(2)O(2) at 30 and 60 micro M had no effect on sperm motility. At 120 micro M of H(2)O(2), a significant reduction (90-95%) in motility was observed after 120 min. However, at 600 micro M of H(2)O(2), all the sperm were found immotile within 15 min of incubation. At much higher concentrations (1200-1500 micro M), the effect was immediate. After immobilization with H(2)O(2) (600 micro M in media), viability in sperm declined to 36% after 30 min, and was further reduced to 5% in 60 min. On the other hand, hypo-osmotic swelling response in these sperm went down drastically from 72 to 46% immediately after immobilization and there was no response at all after 60 min. In contrast, when Triton-x-100 (0.01%), a known spermicidal agent, was used in place of H(2)O(2), the immediate loss of sperm motility corresponded simultaneously with the loss of the other two functional parameters. Further, H(2)O(2) immobilized sperm revealed reduced (25-30%) nuclear chromatin decondensation as compared to 70% for the controls. A composition containing 2% H(2)O(2) in 0.9% NaCl was tested in rats as a vaginal contraceptive, depicting 100% efficacy in mating studies after 2 h of vaginal application. The findings indicate the potential of developing a water-based vaginal contraceptive using H(2)O(2) at an optimal concentration as utilized in the present study.

Cell Nucleus↗

PubMed2002

Effect of styrene maleic anhydride (SMA) on viability and integrity of isolated rat oocytes in vitro.

In vitro spermicidal property of the polymer, styrene maleic anhydride (SMA), a compound under clinical trial as an intravasal male contraceptive, is already established. The present study was designed to evaluate the effect of the polymer (SMA) on the viability and integrity of rat oocytes in vitro. The pH-lowering effect of this polymer was evident following precipitation in Medium 199. Oocytes became nonviable with clearly resolved granulated cytoplasm following incubation with undiluted polymeric first wash medium. Dilution of polymeric wash medium prolonged the integrity and viability of oocytes under incubation. The potency of the first wash medium in terms of affecting the viability of oocytes was highest among different washes and dilutions. Bulging of cytoplasm and an enlarged zona pellucida envelope were observed in a few oocytes treated with the first wash. These findings have shown that, like sperm, oocytes also lose their integrity and viability when coincubated with the polymer or medium containing the polymer. However, developing an appropriate technology for delivery is crucial to exploit this potency of the polymer for development of a female contraceptive.

Animals↗

PubMed1998

Effect of cyclosporine on fertility in male rats.

The effect of cyclosporine (CsA) on fertility has assumed greater importance with the increasing numbers of pediatric transplantations being performed all over the world. Conflicting reports on the effects of CsA on sex hormones are available. This experimental animal study was designed to examine the effect of CsA on testicular weight, sperm counts, seminiferous tubular diameter (STD), testicular morphology, DNA flowcytometry, sex hormone levels, and fertility in male rats. Those rats who received CsA (20 mg/kg per day) showed significant reductions in testicular weight (P < 0.05), sperm count (P < 0.01), Johnsen score (P < 0.05), STD (P < 0.01), serum testosterone levels (P < 0.05), haploid cell population (P < 0. 001) in the testis, and fertility (P < 0.001) compared to those receiving CsA 10 mg/kg per day and control rats. These findings will have an important bearing for children receiving cyclosporine for long periods to guide the physician in optimally adjusting long-term treatment.

Animals↗

PubMed1997

Effect of vitamin A excess on germ cell development in prepubertal rat testis.

Vitamin A in graded doses of 125, 250 and 375 U.S.P./kg body wt, po, for 10 days (d 21-30) drastically reduced the testicular weight by 25 to 62% and seminiferous tubular diameter by 14 to 35% in prepubertal rats in lowest and highest doses of the treatment. The treatment induced disproportionate enlargement of nuclei and cytoplasm of the germ cells; predominantly the preleptotene and pachytene spermatocytes. These abnormal germ cells, often with 2 or 3 nuclei displayed vacuolated cytoplasm surrounding pyknotic or granulated or dispersed chromatin granules within the nuclei in a dose proportionate manner. The round spermatids were the most sensitive cell types which completely disappeared in two higher doses of treatment. Vacuolation of Sertoli cell cytoplasm in about 25% of the tubules with associated increase in intertubular space was also observed in rats treated with the highest dose of the vitamin. Circulatory levels of FSH, LH and testosterone remained unaltered following the vitamin excess treatment. Therefore, it is suggested that excess vitamin A even for shorter duration like the present one is detrimental to developing cell types and prevents the progress of the spermatogenic process beyond the round spermatid stage.

Animals↗

PubMed1993

Is testosterone essential for maintenance of normal morphology in immature rat Leydig cells?

Selective deprivation of gonadotrophins in prepubertal rats by administration of a GnRH antagonist (Ac-D2Nal1, D4ClPhe2, DTrp3, DArg6, DA1a10-GnRH; GnRH code: 103-289-10, National Institutes of Health, USA) for 3 weeks, initiated at 20-22 days of age, induced morphological changes in the Leydig cells, including thickening and indentation of the nuclear margin, pyknosis and elongation of the nuclei. Mean nuclear diameter was reduced to 22% of that in the controls. Under the electron microscope the cells exhibited reduced volume of the nucleus and cytoplasm and the plasma membrane was irregular. This abnormal appearance of the Leydig cells improved marginally in 20-30% of the Leydig cells and their mean nuclear diameter increased to 39% of the control level after FSH supplementation (20 micrograms ovine FSH/day). Normal morphological integrity of the Leydig cells consisting of round or oval nuclei, a smooth nuclear and cellular margin and the original mean nuclear diameter was restored completely when testosterone (30 micrograms/day) was administered to GnRH antagonist-treated rats, with or without simultaneous administration of FSH; in these rats testosterone levels in blood were also restored to normal. These findings indicate that testosterone may be important for the maintenance of normal Leydig cell morphology in the rat.

Animals↗

PubMed1992

Differential response of testis and serum gonadotropins to testosterone in rats treated with a gonadotropin releasing hormone antagonist or estradiol 17 beta.

Adult rats treated with a GnRH antagonist (Ac D2Nal1, D4Cl Phe2, DTrp3, DArg6, DAla10 GnRH; code: 103-289-10, National Institutes of Health, USA) for 5 weeks (250 micrograms/kg b.w) showed multiple degrees of impairment and atrophy of the genital organs concomitant with decreased serum levels of testosterone, LH and FSH. Inhibition of spermatogenesis was characterized by germ cell degeneration and overall decline in different cell numbers and in particular, spermatids of any kind were completely absent. Testosterone supplementation (60 micrograms/rat/day, sc) to GnRH antagonist treated rats, for the same period, significantly elevated the weights of the sex organs, and the serum levels of hormones. Spermatogenesis was improved both qualitatively and quantitatively; albeit failed to be restored back to control levels. Treatment with estradiol 17 beta (1 microgram/rat/day) for 5 weeks had insignificant effect on spermatogenesis but the weights of the genital organs (seminal vesicles by 19% and ventral prostate by 40%) and the levels of serum hormones (LH by 24%, FSH 22% and testosterone by 25%) were otherwise reduced. Administration of testosterone either alone or in combination with estradiol 17 beta had only a marginal effect on spermatogenesis or on other reproductive parameters. The results indicate a positive shift in the response of the testis and serum levels of gonadotropins to testosterone supplementation in rats treated with either GnRH antagonist or estradiol 17 beta.

Animals↗

PubMed1990

Effect of STS-557 (17 alpha-cyanomethyl 17 beta-hydroxy-estra-4, 9(10)-dien-3-one) on blood hormone levels, the testis, accessory sex organs and fertility of rats.

Treatment with STS-557 (17 alpha-cyanomethyl 17 beta-hydroxy-estra-4,9(10)-dien-3-one; 10 mg kg-1 daily s.c.) for 4 weeks induced atrophy of the seminiferous tubules in adult rats with a reduction in tubule diameter and in the number of round spermatids at stage VII. Elongated spermatids were not detected. Leydig cells were atrophied from the second week of treatment with a concomitant decrease in blood levels of testosterone. The blood levels of FSH and LH were reduced from the third week of treatment. The weight of the reproductive organs was reduced after STS-557 treatment. The treatment induced sterility in 50% of rats after 2 weeks of treatment but after 4 weeks none of the treated males mated. Normal fertility and normal levels of testosterone and FSH were restored after 6 weeks and LH after 4 weeks of withdrawal of treatment. All other parameters studied recovered to pretreatment levels 6 weeks after withdrawal of treatment. STS-557 could act on the pituitary-gonadal axis (reducing gonadotrophin secretion) as well as directly affecting the Leydig cells. The consequent reduction in the blood levels of testosterone in combination with reduced gonadotrophins was presumably responsible for the suppression of spermatogenesis.

Animals↗

PubMed1990

Atypical flagellar structure associated with endocrine cells of rat pituitary.

Atypical flagellar structures containing eight subfibers arrayed around a single, central element (8 + 1) are associated with pituitary secretory cells, largely gonadotropes. Less frequently, flagella with a 7 + 2 pattern are seen. Both types appear commonly in pituitary tissues obtained from both male and female rats above 1 year of age and appear to penetrate the cells. Except for the pattern of the array, the structures are similar in dimension to commonly observed flagellar structures (9 + 2) when viewed in sections cut either in perpendicular or sagittal to the major axis. The (8 + 1) flagella are observed both singly and in pairs. Steroidal milieu (ovariectomy with or without steroid replacement) does not seem to influence their appearance. Flagella with the common 9 + 2 arrangement are not observed in the rat pituitary.

Animals↗