Biomedical subjects

D E Bjorling

Publications and source records attributed to D E Bjorling.

At least 19 recordsLinked to original sources

PubMed2003

Progesterone induces the proliferation of urothelial cells in an epidermal growth factor dependent manner.

PURPOSE: We have previously reported that estrogen induced proliferation of urothelial cells is modulated by nerve growth factor (NGF). In this study we investigated whether progesterone induces urothelial cell proliferation and whether this effect is modulated by NGF or by epidermal growth factor (EGF). MATERIALS AND METHODS: Experiments were performed using human urothelial cells immortalized by human papillomavirus E6. Cell proliferation was determined using the alamarBlue (Trek Diagnostic, Westlake, New York) assay. Human papillomavirus were seeded in 48-well plates. They were incubated with 5% alamarBlue and different concentrations of progesterone, EGF or NGF in the presence or absence of neutralizing EGF or NGF antibody, K252a (an inhibitor of trkA, the high affinity receptor for NGF), Ru-486 (an antagonist of progesterone and glucocorticoid receptor) or ZK 137 316 (a specific antagonist of progesterone receptor). Immunoblotting was performed using specific antibodies for progesterone receptor, glucocorticoid receptor or EGF receptor. EGF content in conditioned medium was determined by enzyme-linked immunosorbent assay. RESULTS: In the presence of 10 nM to 1 microM progesterone urothelial cell proliferation was significantly increased 8.6% to 51.1%. This effect was abolished by ZK137 316 or by Ru-486. Hydrocortisone also induced urothelial cell proliferation. This effect was blocked by Ru-486 but not by ZK137 316. In addition, progesterone stimulated urothelial cell proliferation was inhibited by neutralizing EGF antibody but not by NGF antiserum or K252a. We also found that EGF synthesis and release by urothelial cells was increased by exogenous progesterone. This effect of progesterone was inhibited by ZK 137 316. CONCLUSIONS: These findings indicate that progesterone has the capacity to induce urothelial cell proliferation through its cognate receptor and this effect is mediated by EGF but not by NGF.

Carbazoles↗

PubMed2002

Modulation of nerve growth factor in peripheral organs by estrogen and progesterone.

Nerve growth factor (NGF) synthesized in peripheral organs plays a critical role in the development and maintenance of the nervous system and also participates in processing nociceptive stimuli. Previous studies suggest that reproductive hormones may regulate the expression of NGF. Ovariectomies were performed on female mice, and mice were killed 24 h after hormone replacement to evaluate the effects of estrogen and progesterone on NGF in peripheral organs, specifically the uterus, bladder, heart, and salivary gland. Sham-operated intact mice and untreated ovariectomized mice served as controls. Immunohistochemistry demonstrated the presence of NGF, estrogen receptor-alpha, estrogen receptor-beta, and progesterone receptors in these organs. Ovariectomy caused a significant decrease in NGF protein content in the uterus, and short term treatment of ovariectomized mice with estrogen and/or progesterone increased uterine NGF mRNA and restored NGF protein to concentrations similar to intact control mice. Ovariectomy did not affect NGF protein concentrations in the salivary gland, but treatment of ovariectomized mice with estrogen alone or in conjunction with progesterone stimulated concentrations of NGF protein that exceeded those observed in intact control or ovariectomized, untreated mice. NGF mRNA was increased in salivary glands from ovariectomized mice treated with progesterone alone or in combination with estrogen relative to other groups. NGF protein content of the hearts of ovariectomized mice treated with estrogen alone or in conjunction with progesterone was increased relative to intact controls and ovariectomized, untreated mice, but neither ovariectomy or hormone replacement affected NGF mRNA content in the heart. NGF protein content of the bladder was unaffected by ovariectomy or hormone treatment, and bladder NGF mRNA was unaffected by ovariectomy or hormone treatment. Collectively, these results indicate that reproductive hormones have the capacity to regulate NGF message and protein in a manner that varies among organs. Fluctuations in the expression of NGF, in conjunction with other factors, may help to explain gender differences in pain sensation and inflammatory response.

Animals↗

PubMed2002

LPS-sensory peptide communication in experimental cystitis.

Stimulation of sensory nerves can lead to release of peptides such as substance P (SP) and consequently to neurogenic inflammation. We studied the role of bacterial lipopolysaccharide (LPS) in regulating SP-induced inflammation. Experimental cystitis was induced in female mice by intravesical instillation of SP, LPS, or fluorescein-labeled LPS. Uptake of fluorescein-labeled LPS was determined by confocal analysis, and bladder inflammation was determined by morphological analysis. SP was infused into the bladders of some mice 24 h after exposure to LPS. In vitro studies determined the capacity of LPS and SP to induce histamine and cytokine release by the bladder. LPS was taken up by urothelial cells and distributed systemically. Twenty-four hours after instillation of LPS or SP, bladder inflammation was characterized by edema and leukocytic infiltration of the bladder wall. LPS pretreatment enhanced neutrophil infiltration induced by SP, increased in vitro release of histamine, tumor necrosis factor-alpha, and interferon-gamma, and significantly reduced transforming growth factor-beta1 release. These findings suggest that LPS amplifies neurogenic inflammation, thereby playing a role in the pathogenesis of neurogenic cystitis.

Administration, Intravesical↗

PubMed2001

Effects of hydromorphone or oxymorphone, with or without acepromazine, on preanesthetic sedation, physiologic values, and histamine release in dogs.

OBJECTIVE: To compare hydromorphone with oxymorphone, with or without acepromazine, for preanesthetic sedation in dogs and assess changes in plasma concentration of histamine after drug administration. DESIGN: Randomized clinical study. ANIMALS: 10 healthy mixed-breed dogs. PROCEDURE: Dogs were treated IM with hydromorphone (group H), oxymorphone (group O), hydromorphone with acepromazine (group H/A), or oxymorphone with acepromazine (group O/A). Sedation score, heart rate, respiratory rate, systolic blood pressure, and oxygen saturation were recorded at baseline immediately after drug administration (T0) and every 5 minutes for 25 minutes (T25). Plasma histamine concentration was measured at baseline and T25. RESULTS: Sedation was similar between groups H and 0 at all times. Sedation was significantly greater for groups H/A and O/A from T10 to T25, compared with other groups. Systolic blood pressure was significantly reduced at T25 in group H/A, compared with group H, and in group O/A, compared with group O. Prevalence of panting at T25 was 50% for groups H and O, compared with 20% for group H/A and 30% for group O/A. By T25, heart rate was significantly lower in all groups. Oxygen saturation was unaffected by treatment. Mean +/- SD plasma histamine concentration was 1.72 +/- 2.69 ng/ml at baseline and 1.13 +/- 1.18 ng/ml at T25. There was no significant change in plasma histamine concentration in any group. CONCLUSIONS AND CLINICAL RELEVANCE: Hydromorphone is comparable to oxymorphone for preanesthetic sedation in dogs. Sedation is enhanced by acepromazine. Neither hydromorphone nor oxymorphone caused an increase in plasma histamine concentration.

Acepromazine↗

PubMed2001

Estrogen and neuroinflammation.

Women have a higher incidence of inflammatory disorders than men and also appear to perceive painful stimuli differently. It has been suggested that neuroinflammation plays a role in painful bladder disorders of uncertain etiology, such as interstitial cystitis. Nerve growth factor (NGF) is a neurotrophin produced in peripheral tissues that can also mediate pain and inflammation. We found that treatment of mice with the estrogen antagonist ICI 182,780 had no effect on bladder NGF content but decreased bladder NGF messenger RNA. Using immunohistochemistry, we demonstrated that the mucosa is the primary source of NGF in the mouse bladder, and the bladder mucosa also expresses estrogen receptor (ER)-alpha, ER-beta, and the high-affinity NGF receptor tyrosine kinase A. Estrogen may also modulate neurogenic inflammation by interaction with other substances and cells that participate in the pathogenesis of neurogenic inflammation, including substance P, bradykinin, and mast cells. Collectively, these observations indicate that estrogen has the capacity to influence the onset and course of neurogenic inflammation of the bladder.

Animals↗

PubMed2001

Intravesical Escherichia coli lipopolysaccharide stimulates an increase in bladder nerve growth factor.

OBJECTIVE: To investigate the effects of the intravesical instillation of Escherichia coli lipopolysaccharide (LPS) on nerve growth factor (NGF, which may mediate the pain associated with inflammation) protein and mRNA in the bladders of mice. MATERIALS AND METHODS: E. coli LPS was instilled into the bladders of female mice; the whole-bladder NGF content was then determined by an enzyme-linked immunosorbent assay and the NGF mRNA content of the bladder determined by semiquantitative reverse transcription-polymerase chain reaction. Bladder NGF was also evaluated by immunohistochemistry in some of the mice. RESULTS: LPS stimulated a significant increase in bladder NGF 90 min after instillation, but bladder NGF content was significantly less than that in bladders of control mice 3 and 7 h after LPS instillation. Twenty-four hours after the intravesical infusion of saline or LPS, there was no difference in NGF content in bladders from saline or LPS-infused mice. Immunohistochemistry confirmed the presence of increased NGF in the mucosa of detrusor from bladders 90 min after LPS instillation. Bladder NGF mRNA increased more slowly in response to LPS, and 7 and 24 h after LPS instillation the relative abundance of NGF mRNA was 1.5 and 2.0 times greater in LPS-infused bladders, respectively. CONCLUSIONS: E. coli LPS can stimulate increased NGF message and protein in the bladder. The increase in NGF protein preceded the increase in mRNA, suggesting that this increase was not the result of gene transcription. It is possible that NGF participates in the pathogenesis of pain associated with bacterial cystitis.

Administration, Intravesical↗

PubMed2001

CLA reduces antigen-induced histamine and PGE(2) release from sensitized guinea pig tracheae.

Conjugated linoleic acid (CLA) has been shown to enhance immune reactions such as lymphocyte blastogenesis and delayed-type hypersensitivity. We investigated the role of CLA in type I (immediate) hypersensitivity, using a guinea pig tracheal superfusion model for measuring antigen-induced airway smooth muscle contraction and inflammatory mediator release. Female Hartley guinea pigs were fed a diet supplemented with 0.25 g corn oil or linoleic acid/100 g of diet (control) or 0.25 g CLA/100 g of diet for at least 1 wk before and during active sensitization to ovalbumin antigen. Tracheae from sensitized guinea pigs were suspended in air-filled water-jacketed (37 degrees C) tissue chambers in a superfusion apparatus. Tracheae were superfused with buffer containing antigen, and tissue contraction was recorded. Superfusate was collected at 90-s intervals for evaluation of histamine and PGE(2) release. CLA did not affect antigen-induced tracheal contractions when expressed as gram contraction per gram tissue. CLA significantly reduced antigen-induced histamine and PGE(2) release. CLA appears to decrease release of some inflammatory mediators during type I hypersensitivity reactions.

Animals↗

PubMed2001

In vitro contractile effects of neurokinin receptor blockade in the human ureter.

PURPOSE: We identified the predominance of neurokinin-2 receptors and evaluated the inhibition of spontaneous contraction via the blockade of neurokinin-2 receptors in human ureteral segments. MATERIALS AND METHODS: Excess ureteral segments from human subjects undergoing donor nephrectomy or reconstructive procedures were suspended in tissue baths containing Krebs buffer. After spontaneous contractions were recorded, tissues were incubated with 1 microM. solutions of phosphoramidon and captopril (to inhibit peptide degradation) and either the neurokinin-1 receptor antagonist CP 99,994, the neurokinin-2 receptor antagonist SR 48,968, the neurokinin-3 receptor antagonist SR 142,801 or dimethyl sulfoxide (control) for 1 hour. Contraction magnitude and frequency were again recorded and compared with spontaneous levels. Concentration-response curves to the tachykinins substance P, and neurokinins A and B were determined in the presence and absence of antagonists. RESULTS: Neurokinin A increased contractility at lower concentrations than substance P or neurokinin B (p <0.013). Neurokinin-2 receptor blockade produced a 100-fold rightward shift of the concentration-response curves (p <0.013), while neurokinins 1 and 3 receptor blockade had no effect. SR 48,968 significantly reduced contractility during the 1-hour incubation period, causing a 97% reduction in spontaneous rates compared with a 29% reduction in control tissues. CP 99,994 and SR 142,801 had no significant effect. CONCLUSIONS: Neurokinin-2 is the predominant receptor subtype responsible for tachykinin induced contraction of human ureteral smooth muscle. In vitro treatment with the neurokinin-2 antagonist SR 48,968 reduces the spontaneous contraction rate by 97% in vitro. Neurokinin-2 receptor antagonists may have clinical applications for ureteral disease.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2000

Determination of mouse bladder inflammatory response to E. coli lipopolysaccharide.

Evaluation of the severity of histologic changes associated with cystitis is often subjective and inconsistent from one sample to the next. The objective of this study was to establish a consistent, reproducible method to quantify histologic changes in a mouse model of lipopolysaccharide (LPS)-induced cystitis. Either LPS (n = 8) or pyrogen-free saline (n = 8) was instilled intravesically into the bladders of female C57bk-6 J mice. Twenty-four hours later, mice in these groups as well as eight untreated controls were sacrificed and bladders were removed, fixed in formalin, and stained with hematoxylin and eosin (H&E). A bladder inflammatory index (BII) was described by reviewing tissues for edema, leukocyte infiltration, and hemorrhage. Cross-sections were evaluated by a single pathologist in a blinded manner based on the objective BII described. The BII method for objectively analyzing bladder inflammation was effective and reproducible. Bladders instilled with LPS had significantly increased inflammation scores for edema, leukocyte infiltration, and hemorrhage compared with those instilled with saline or untreated controls (n = 8, P < 0.05). These results demonstrate that LPS causes bladder inflammation when instilled intravesically and that inflammation of mouse bladders can be objectively quantified using the histological method described.

Animals↗

PubMed2000

Distribution of neuropeptides, histamine content, and inflammatory cells in the ureter.

OBJECTIVES: To determine the anatomic distribution of select neuropeptides (neurokinin A [NKA], substance P [SP], and bradykinin [BK]), of inflammatory cells (leukocytes and mast cells), and the histamine content in the normal swine ureter and compare the findings with regions of increased ureteral contractility. METHODS: Ureters from 10 pigs were obtained and cut into eight segments, proximally to distally. A portion of each ureteral segment was suspended in Krebs buffer (37 degrees C) and attached to force displacement transducers, and spontaneous contractility was measured for 30 minutes. A second portion was assayed for histamine, NKA, SP, and BK using enzyme-linked immunosorbent assay. A third portion was fixed in 10% buffered formalin, stained with hematoxylin-eosin, and evaluated histologically. RESULTS: Ureteral contractility was found to be highest in the most proximal and most distal regions of the ureter. Similarly, SP content was three times greater in the proximal ureter and two times greater in the distal ureter than in the midureter (P <0.05, n = 10). The total NKA and BK content were also higher in the proximal and distal ureter than in the midureter. Conversely, the histamine content was consistent throughout the ureter. Moreover, no significant difference in the distribution of inflammatory cells was identified throughout the ureter. CONCLUSIONS: The anatomic distribution of NKA, SP, and BK in the ureter corresponded to regions of increased spontaneous ureteral contractility, more specifically the proximal and distal ureter. Neuropeptides may play a significant role in ureteral contractility and may be a target for pharmacologic mediation during obstruction and stone passage.

Animals↗

PubMed2000

Substance P dependence of endosomal fusion during bladder inflammation.

Urinary bladder instillation of ovalbumin into presensitized guinea pigs stimulates rapid development of local bladder inflammation. Substance P is an important mediator of this inflammatory response, as substance P antagonists largely reverse the process. Vacuolization of the subapical endosomal compartment of the transitional epithelial cells lining the bladder suggests that changes in endosomal trafficking and fusion are also part of the inflammatory response. To test directly for substance P mediation of changes in endosomal fusion, we reconstituted fusion of transitional cell endosomes in vitro using both cuvette-based and flow cytometry energy transfer assays. Bladders were loaded with fluorescent dyes by a hypotonic withdrawal protocol before endosomal isolation by gradient centrifugation. Endosomal fusion assayed by energy transfer during in vitro reconstitution was both cytosol and ATP dependent. Fusion was confirmed by the increase in vesicle size on electron micrographs of fused endosomal preparations compared with controls. In inflamed bladders, dye uptake was inhibited 20% and endosomal fusion was inhibited 50%. These changes are partly mediated by the neurokinin-1 (NK1) receptor (NK1R), as 4 mg/kg of CP-96,345, a highly selective NK1 antagonist, increased fusion in inflamed bladders but had no effect on control bladders. The receptor-mediated nature of this effect was demonstrated by the expression of substance P receptor mRNA in rat bladder lumen scrapings and by the detection of the NK1R message in guinea pig subapical endosomes by Western blot analysis. The NK1Rs were significantly upregulated following induction of an inflammatory response in the bladder. These results demonstrate that 1) in ovalbumin-induced inflammation in the guinea pig bladder, in vitro fusion of apical endosomes is inhibited, showing endocytotic processes are altered in inflammation; 2) pretreatment in vivo with an NK1R antagonist blocks this inhibition of in vitro fusion, demonstrating a role for NK1R in this process; and 3) the NK1R is present in higher amounts in apical endosomes of inflamed bladder, suggesting changes in translation or trafficking of the NK1R during the inflammatory process. This suggests that NK1R can change the fusion properties of membranes in which it resides.

Animals↗

PubMed2000

Selective cyclooxygenase-2 inhibitors reduce ureteral contraction in vitro: a better alternative for renal colic?

PURPOSE: To quantitate the effects of a selective cyclooxygenase (COX)-2 inhibitor, NS-398, on porcine and human ureteral contractility in vitro. MATERIALS AND METHODS: This study was performed in 3 distinct groups. In group 1, segments of ureter were obtained from freshly sacrificed domestic swine. Sections were isolated and suspended longitudinally. Twenty-four ureteral segments were treated with either indomethacin (a nonselective COX inhibitor), NS-398 (selective COX-2 inhibitor), or DMSO (control). Spontaneous contractions were then recorded in each group. In group 2, fifteen segments of human ureter were obtained from patients undergoing donor nephrectomy or ureteral reimplantation. Segments were isolated and suspended as above, and treated with either indomethacin, NS-398, or DMSO. In group 3, eighteen sections of human ureter obtained from donor nephrectomy patients were passively sensitized for 20 hours in ragweed allergic donor serum. Ureteral segments were then treated with either indomethacin, NS-398 or DMSO, and then the segments were subsequently exposed to ragweed antigen and contractions were subsequently recorded. RESULTS: In group 1, the average time to 100% inhibition of spontaneous contraction was 48.8 minutes (S.E.M. = 7.9) for indomethacin, 65.7 minutes (S.E.M. 6.7) for NS-398, and beyond 150 minutes for DMSO. The percent reduction was 100% for indomethacin (S.E.M. = 0), 92.5% for NS-398 (S.E.M. 4.9%), and 52.9% for DMSO (s.e.m. = 10.8%). In group 2, the average time to 100% inhibition was 29 minutes (S.E.M. = 10.4) for indomethacin, 21 minutes (S.E.M. 4.8) for NS-398, and beyond 150 minutes for DMSO. The percent reduction was 100% for indomethacin (S.E.M. = 0), 100% (S.E.M. = 0) for NS-398, and 20% (S.E.M. = 12%) for DMSO. In group 3, ragweed sensitized ureters treated with DMSO (control group) contracted an average maximum of 10 times per 5 minutes. Antigen failed to induce contractions of sensitized tissues treated with indomethacin or NS-398. CONCLUSION: A selective COX-2 inhibitor (NS-398) reduces ureteral contractility as effectively as indomethacin (a nonselective COX inhibitor) in both porcine and human ureteral segments in vitro (p <0.05). Selective COX-2 inhibitors may have significant clinical potential in treating renal colic as they cause less gastric ulceration.

Animals↗

PubMed1999

NK-2 is the predominant tachykinin receptor subtype in the swine ureter.

OBJECTIVE: To determine which of the known tachykinin receptor subtypes is predominant in the swine ureter. MATERIALS AND METHODS: Ureters from adult pigs were harvested, cut into longitudinal strips and placed in 10 mL tissue baths containing Krebs buffer, under 4 g of initial tension. The magnitude and frequency of contractions were recorded. Tissues were incubated with 1 micromol/L solutions of peptidase inhibitors (phosphoramidon and captopril) for 1 h to inhibit degradation of peptides and treated with either CP 96,345 (NK-1 receptor antagonist), SR 48,968 (NK-2 receptor antagonist) or saline (control). Concentration-response curves to the tachykinins substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) were determined. RESULTS: Ureteric segments showed a concentration-dependent response to all tachykinins; NKA stimulated increased contractions at a lower concentration than either SP or NKB (P<0.05). This was reflected by the difference in the effective concentration required to obtain half the maximal response (EC50 ) for each of the peptides. The mean (sd) EC50 values were (micromol/L): NKA, 0.2 (0.02); SP, 3.5 (0.7); and NKB, 4.5 (1.7). In addition, the selective NK-2 antagonist (SR 48,968) significantly reduced contractile responses to all peptides, as indicated by a 10-fold rightward shift of the concentration-response curves (P<0. 05), whereas the NK-1 antagonist (CP 96,345) had no significant effect. CONCLUSION: These results indicate that NK-2 is the predominant tachykinin receptor subtype responsible for contraction of ureteric smooth muscle. The use of mediators which act on NK-2 receptors may have clinical applications for the treatment of ureteric disease.

Animals↗

PubMed1999

Mast cells mediate the severity of experimental cystitis in mice.

PURPOSE: We hypothesized that experimental cystitis induced by substance P (SP) or E. coli lipopolysaccharide (LPS) would be less severe in mice rendered mast cell deficient by genetic manipulation. MATERIALS AND METHODS: Two strains of mast-cell deficient mice (WBB6F1- kitW/kitW-v or kitW/kitW-v and WCB6F1-Sl/Sld or Sl/Sld) and their congenic, normal (+/+) counterparts were used. Cystitis was induced in female mice by intravenous injection of SP (0.1 ml.; 10(-6) M) or E. coli LPS (0.1 ml.; 2 mg./ml.), and inflammation was assessed by Evans blue dye extravasation. In a separate group of kitW/kitW-v and congenic normal mice, cystitis was induced by intravesical infusion of SP (0.05 ml.; 10(-5) M) or E. coli LPS (0.05 ml.; 100 microg./ml.) and compared with intravesical pyrogen-free saline (0.05 ml.; 0.9%). Severity of cystitis was determined by histological evaluation of the bladder wall 24 hours after intravesical infusions. RESULTS: Intravenous SP or LPS stimulated increased plasma extravasation in congenic normal mice but not in mast cell-deficient mice. Intravesical SP or LPS resulted in increased edema, leukocytic infiltration, and hemorrhage within the bladder wall in congenic normal mice, but the only histological evidence of inflammation in the bladders of kitW/kitW-v mice was increased hemorrhage in response to LPS. CONCLUSIONS: This study indicates that mast cells modulate the inflammatory response of the bladder to SP and LPS in mice. Although clinical trials of the use of antihistamines to treat or prevent cystitis have not been successful, these results suggest that therapies directed toward preventing mast cell activation may yet prove effective in treating cystitis.

Animals↗

PubMed1998

Lipopolysaccharide upregulates bradykinin 1 receptors in the isolated mouse bladder.

PURPOSE: Bradykinin 1 (B1) receptors have been shown to be upregulated at sites of inflammation. The purpose of this study was to determine the effect of lipopolysaccharide (LPS) on B1 receptor modulation in the isolated mouse bladder. MATERIALS AND METHODS: The contractile responses of isolated mouse bladder to B1 and B2 agonists were determined in vitro following prolonged incubation with LPS or saline. RESULTS: Bradykinin (BK), a B2 agonist, but not des-Arg9-bradykinin (DABK), a B1 agonist, was found to be a potent contractile agonist of the mouse urinary bladder under basal conditions. However, both sensitivity and maximal response to DABK increased during a second exposure to the agonist in a time-dependent manner. In vivo or in vitro treatment with LPS increased both sensitivity and maximal response of isolated bladders to DABK, whereas bladder contraction to BK and other peptides remained the same. Treatment of tissues with a B1 receptor antagonist 45 minutes prior to second exposure to DABK, or the prostaglandin synthesis inhibitor, indomethacin, 30 minutes prior to LPS or saline incubation, significantly inhibited the increase of both maximal response and sensitivity. CONCLUSIONS: These results indicate that bladder B1 receptors can be upregulated by LPS, and that prostaglandins seem to mediate the effects of the B1 receptor activation in the isolated mouse bladder.

Animals↗

PubMed1998

In vitro passive sensitization of the ureter as a basis for the study of noninfectious ureteral inflammation.

PURPOSE: To develop an in vitro model of passive sensitization for the ureter for the study of noninfectious ureteral inflammation. MATERIALS AND METHODS: Human ureteral tissues were obtained from excess segments of ureters from patients undergoing donor nephrectomy. Following excision, ureters were placed in physiologic salt solution (PSS) and passively sensitized by incubating with ragweed serum from allergic donor (1 ml. serum: 4 ml. PSS) for 20 hours at room temperature. Ureteral segments were incubated with PSS only and served as non-sensitized controls (n = 4). After sensitization, excess serum was removed by serial washing with PSS without serum. Ureteral strips were then suspended in vitro for determination of tissue contraction. Contractile responses and histamine release were measured. Tissues were then exposed to antigen. To investigate the role of inflammatory mediators in tissue contraction, 4 groups of 8 sensitized ureteral segments were incubated for 1 hour with the following substances: a H1 histamine receptor antagonist (pyrilamine), an inhibitor of prostaglandin synthesis (indomethacin), an inhibitor of leukotriene synthesis (A-64077), and a control substance (DMSO). Following incubation, the tissues were exposed to antigen, and contraction and histamine release were determined. RESULTS: Sensitized ureteral segments (n = 8) responded to antigen with contraction (30% BaCl maximum; p <0.01) and histamine release (205/ng./gm. tissue) within the first 5 minutes of superfusion. Non-sensitized control segments (n = 4) did not respond. Both indomethacin and pyrilamine reduced (7-10% of BaCl maximum; p <0.05) the contractile response of sensitized ureter to antigen, whereas A-64077 did not. Analysis of the superfusate for histamine indicates that indomethacin reduced histamine release (150 ng./gm.) whereas A-64077 and pyrilamine did not (p <0.05). CONCLUSION: We have demonstrated that ureteral segments can be passively sensitized and that subsequent antigen challenge stimulates contraction and histamine release. Our findings suggest that contraction of ureteral tissue and histamine release may be utilized as an inherent bioassay indicating the activity of inflammatory mediators. In addition, these results suggest that both prostaglandins and histamine, but apparently not leukotrienes, participate in the early inflammatory response to antigen challenge of the sensitized ureter.

Antigens↗

PubMed1997

Prepubic urethrostomy for relief of urethral obstruction in a sheep and a goat.

Urethral obstruction is common in castrated male small ruminants. Perineal urethrostomy is the recommended treatment in animals not intended for breeding; however, stricture formation is a common complication, and few surgical options are available once a stricture has formed. Prepubic urethrostomy has been used successfully in dogs and cats to treat urethral trauma or stricture formation, and in this report, use of prepubic urethrostomy in 2 small ruminants to treat urethral strictures that developed alter perineal urethrostomy is described. Both animals maintained urinary continence and were able to void urine normally. Complications after prepubic urethrostomy included recurrent cystitis in sheep and urethral stricture in goats. Prepubic urethrostomy may be considered in as an alternative for treatment of urethral disorders in small ruminants.

Animals↗

PubMed1997

Use of gold-labeled ovalbumin to correlate antigen deposition and localization with tissue response.

This study was performed to evaluate a technique for correlating the location of antigen within sensitized tissues with physiological response. Guinea pigs actively sensitized by intraperitoneal injection of ovalbumin (OVA) were euthanized, and urinary bladders were removed. Gold beads (18 nM diameter) were conjugated to OVA (OVA-Au) and bovine serum albumin (BSA-Au). Bladder tissue was suspended in tissue baths, exposed to OVA, OVA-Au, BSA, and BSA-AU, and tissue contraction and histamine release were determined. Bladder tissues were examined by electron microscopy to determine distribution of gold-labeled antigen at 1 and 5 min after exposure. Exposure of bladder tissue from sensitized guinea pigs to OVA stimulated concomitant contraction and histamine release which reached maximal levels within 3 min; bladder tissue from control, nonsensitized guinea pigs did not respond to OVA. BSA failed to stimulate response from OVA-sensitized or control bladder tissue. Labeled antigen was adhered to mucosa of sensitized bladder tissue 1 min after exposure to OVA-Au. OVA-Au was present within the mucosa and submucosa of sensitized tissues within 5 min. OVA-Au did not adhere to, or become internalized by, control tissues, and BSA-Au did not adhere to, or become internalized by, any tissues. Labeling of antigen with gold allowed the location of antigen within tissues to be determined and did not affect the response of sensitized tissues to antigen exposure.

Animals↗