Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The local motor response to bradykinin and the bacterial chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP) was investigated in the guinea-pig isolated renal pelvis and ureter in relation to possible activation of capsaicin-sensitive primary afferent nerves and release of sensory neuropeptides. Both bradykinin (1 nM-10 microM) and FMLP (10 nM-10 microM) produced a concentration-dependent positive inotropic effect in the isolated renal pelvis which was unaffected by in vitro capsaicin desensitization. The response to bradykinin was antagonized by HOE 140, a bradykinin receptor antagonist, while it was unaffected by MEN 10,376, a tachykinin receptor antagonist, hCGRP(8-37) a calcitonin gene-related peptide (CGRP) receptor antagonist and N-t-BOC-Phe-DLeu-Phe-DLeu-Phe (BPLPLP), an FMLP antagonist. The response to FMLP was blocked by BPLPLP while it was unaffected by HOE 140, MEN 10,376 or hCGRP(8-37). Indomethacin (10 microM) enhanced the response to both bradykinin and FMLP. Bradykinin transiently activated rhythmic contractions in the isolated ureter. The response to bradykinin was blocked by HOE 140 and was unaffected by in vitro capsaicin desensitization, indomethacin, MEN 10,376 or BPLPLP. FMLP had no motor effect on the resting ureter but when rhythmic background contractions were evoked by the addition of 100 nM endothelin 1, it produced a transient suppression of ureteral motility. This inhibitory effect was unchanged by in vitro capsaicin desensitization or HOE 140 while it was abolished by indomethacin or BPLPLP pretreatment. Both bradykinin and FMLP evoked the release of CGRP-like immunoreactivity in the renal pelvis. The effect of bradykinin but not that of FMLP was abolished by indomethacin. By contrast neither bradykinin nor FMLP did evoke a significant CGRP-LI release in the ureter. It is concluded that bradykinin and FMLP affect pyeloureteral motility through specific and independent pathways. The local motor responses produced by these chemical stimulants are independent from the release of sensory neuropeptides from capsaicin-sensitive primary afferent neurons. Direct neurochemical evidence was obtained for activation of capsaicin-sensitive primary afferents in the renal pelvis: such a mechanism could be involved in the genesis of ureteral pain whenever bradykinin or FMLP come into contact with sensory nerves in the pyeloureteral wall.
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PMID:Local motor responses to bradykinin and bacterial chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP) in the guinea-pig isolated renal pelvis and ureter. 133 50

We investigated the binding characteristics of endothelin (ET) receptors in rabbit ureter, bladder dome, bladder base, and urethra and compared the observed receptor properties with those of cloned human ETA and ETB receptors expressed in Chinese hamster ovary K-1 (CHO) cells. Receptor binding experiments with [125I]ET-1 revealed the presence of a single class of specific, saturable, high affinity [125I]ET-1 binding sites in all of the regions of the studied urinary tract. The rank order of the densities (Bmax values) of [125I]ET-1 binding sites was: ureter "bladder dome > bladder base = urethra. ET-1 and ET-2 inhibited [125I]ET-1 binding to the membrane particulates from the various regions of the urinary tract with single high affinity constants. A selective ETA receptor antagonist, BQ 123, and selective ETB agonists, ET-3 and sarafotoxin S6c (STXc), inhibited [125I]ET-1 binding to bladder dome, bladder base, and urethra with high and low affinity constants indicating the presence of both ETA and ETB receptor subtypes in these tissues. The subtype specificity of ET receptors in the rabbit tissues is confirmed with inhibition data obtained from similar binding studies in cloned human ETA and ETB receptors. The proportions of high affinity binding sites for ET-3, representing ETB receptors, were approximately 25%, 27%, and 46% in bladder dome, bladder base, and urethra, respectively. Corresponding values for STXc were approximately 17%, 28%, and 43% in bladder dome, bladder base, and urethra, respectively. In contrast to the findings for ET-3 and STXc, the proportions of high affinity binding sites for BQ 123, representing ETA receptors, in bladder dome, bladder base, and urethra were approximately 84%, 74%, and 60%, respectively. In ureter, these selective compounds inhibited [125I]ET-1 binding with either a low (ET-3 and STXc) or a high binding affinity (BQ 123), suggesting the presence of only a single receptor subtype (ETA) in this tissue. These data indicate that there are regional differences in the density and subtype specificity of ET receptors in the rabbit urinary tract.
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PMID:Regional differences in the density and subtype specificity of endothelin receptors in rabbit urinary tract. 875 Oct 73

We investigated the binding characteristics of endothelin (ET) receptors in the ureters of rats with experimentally induced diabetes and diuresis. Receptor binding experiments demonstrated an upregulation in the expression of [125I]ET-1 binding sites in the diabetic rat ureter but not in the diuretic rat ureter. ET-1, ET-3, IRL 1620, and BQ 610 inhibited [125I]ET-binding to the rat ureter consistent with the predominance of ETA receptors in these tissues. The subtype specificity of ET receptors in ureteral tissues was confirmed with inhibition data obtained from cloned human ETA and ETB receptors.
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PMID:Experimental diabetes upregulates the expression of uretereral endothelin receptors. 935 71

Unilateral ureteral obstruction (UUO) is a well-established model for the study of interstitial fibrosis in the kidney. It has been shown that the renin-angiotensin system plays a central role in the progression of interstitial fibrosis. Recent studies indicate that endothelin, a powerful vasoconstrictive peptide, may play an important role in some types of renal disease. To investigate the effects of angiotensin II on endothelin and its receptors in the kidney, mice were subjected to UUO and treated with or without enalapril, an orally active angiotensin-converting enzyme inhibitor, in their drinking water (100 mg/l). The animals were killed 5 days later. Using RT coupled with PCR, we measured the levels of endothelin-1, endothelin A, and endothelin B (ET(B)) along with transforming growth factor-beta, TNF-alpha, and collagen type IV mRNA expression in the kidney with UUO and the contralateral kidney along with interstitial expansion in the kidney cortex by a standard point counting method. We found that enalapril administration ameliorated the increased expression of ET-1 mRNA in the obstructed kidney by 44% (P < 0.02). Although the level of endothelin A mRNA expression was significantly increased in the obstructed kidney, it was not affected by enalapril. We found that enalapril treatment increased ET(B) mRNA expression by 115% (P < 0.05) and protein expression (measured by Western blot) in the kidney with an obstructed ureter. Enalapril treatment alone inhibited the expansion of interstitial volume due to UUO by 52%. Cotreatment with enalapril and the ET(B) receptor antagonist BQ-788 inhibited the expression of interstitial volume by only 19%. This study confirms that enalapril inhibits the interstitial fibrosis in UUO kidneys. It also suggests a beneficial and unforeseen effect of enalapril on the obstructed kidney by potentially stimulating the production of nitric oxide through an increased expression of the ET(B) receptor.
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PMID:ACE inhibition increases expression of the ETB receptor in kidneys of mice with unilateral obstruction. 1247 37