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Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The autonomic receptor functions of ureteral smooth muscle were studied in vitro on strips of human ureter obtained at surgery. A dose-dependent, reproducible, contraction response to 5-hydroxytryptamine (Serotonin, 5-HT) was demonstrated. This response could be blocked by methysergide. Responses to acetylcholine and to drugs stimulating adrenergic receptor functions were also found, but they were weak and inconsistent. This suggests that contraction of ureteral smooth muscle is mediated through receptors which are sensitive to 5-hydroxytryptamine.
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PMID:Autonomic receptor functions of the human ureter: an in vitro study. 20 92

1. Electrophysiological techniques were used to characterize responses of afferent fibers in pelvic nerve of adult, virgin female rats to mechanical or chemical stimulation of internal reproductive organs and to mechanical stimulation of other pelvic organs. 2. In an in vivo barbiturate-anesthetized preparation, pelvic nerve afferent fibers responded to a wide variety of mechanical stimulation applied to restricted regions of the vaginal canal, caudal uterus (body and cervix), bladder, ureter, colon, or anus. 3. Single-fiber mechanoreceptive fields were invariably confined to a single organ. Notably, responses could be evoked not only by gentle stimulation of the unit's receptive field directly on the organ itself, but also by stimulating the field indirectly with intense stimulation through the appropriate part of a contiguous organ. This innervation feature is consistent with the separability of pelvic organ functions under innocuous conditions but their confusion under noxious ones. 4. Receptive fields on the reproductive organs extended from the caudal edge of the vagina to the uterine body (including the cervix) but were most often located in the fornix (vaginocervical junction). Most units had no or low levels of spontaneous activity. Their responses to mechanical stimuli were usually slowly or moderately adapting and time-locked to the stimulus. 5. Fibers with vaginal receptive fields (including the fornix) responded best either to vaginal distension with a balloon or, more often, to a probe moving along the internal vaginal surface in a direction toward the cervix. They were observed most frequently during the proestrus stage of the rat's estrous cycle. These fibers, therefore, seem particularly suited for relaying information about stimuli that occur during mating. 6. Fibers with receptive fields on the uterine cervix and body responded best to static pressure and were observed less frequently than those with vaginal fields, regardless of estrous stage. They were, however, sensitized by hypoxia. In addition, irritation of the uterus increased the probability of observing them. These fibers, therefore, may exert their primary function during reproductive conditions different from those of virgin rats, such as parturition. 7. Response activity of most of the mechanoreceptive afferent fibers supplying reproductive organs increased as the stimulus intensity increased into the noxious range; i.e., into a range in which the stimulus momentarily produced ischemia at the stimulus site. In addition, in an in vitro preparation, pelvic nerve fibers responded in a dose-dependent manner to injections through the uterine artery of bradykinin (BRAD) as well as to other algesic chemicals, 5-hydroxytryptamine (5-HT) and KCl.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Functional properties of afferent fibers supplying reproductive and other pelvic organs in pelvic nerve of female rat. 231 44

1. A method of recording the peristaltic frequency and the rate of transport of fluid (perfusion rate) in the rat ureter in vivo is described.2. Acetylcholine and atropine did not alter ureteral activity. Histamine increased the rate of peristalsis by up to 15% and the rate of perfusion by up to 10%. Low doses of 5-hydroxytryptamine increased peristaltic frequency whereas high doses decreased peristaltic frequency; all doses reduced the rate of perfusion.3. Morphine reduced the rate of perfusion by 5-10% at all dose levels, but only the highest dose used reduced the frequency of ureteral peristalsis.4. (-)-Adrenaline, (-)-noradrenaline and (+/-)-isoprenaline reduced the frequency of peristalsis. The order of potency was isoprenaline>noradrenaline>adrenaline. The response was dose-related and blocked by propranolol, which itself did not affect ureteral activity.
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PMID:The pharmacology of the rat ureter in vivo. 504 47

Intravenous injection of compound 48/80 (1 mg X kg-1) induced an acute increase in vascular permeability to plasma proteins in various organs of rats. The compound 48/80 response was partly inhibited by histamine H1 and H2 receptor blockade in the urinary bladder and in the duodenum, but not in the trachea, the oesophagus, the ureter and the paw skin. Blockade of 5-hydroxytryptamine receptors with methysergide led to a reduction of the permeability response in the oesophagus and in the urinary bladder, leaving responses in other organs unchanged. Pretreatment of neonatal rats with capsaicin almost abolished the 48/80 response in all organs except in the duodenum. Pretreatment of rats with [D-Arg1, D-Trp7,9, Leu11]-substance P, a substance P antagonist, also caused a partial inhibition of the permeability response to compound 48/80 in several organs. Topical administration of compound 48/80 (1 mg X ml-1) onto the tracheal mucosa induced local Evans blue extravasation. This response was resistant to pretreatment with histamine receptor antagonists, but was largely inhibited after neonatal capsaicin pretreatment. Topical administration of compound 48/80 (1 mg X ml-1 or 10 mg X ml-1) into the eye did not cause visible Evans blue extravasation in the conjunctiva, nor any signs of pain reaction as indicated by the absence of the wiping response, usually seen upon noxious chemical stimuli in the eye. In guinea-pigs, 10 mg X kg-1 compound 48/80 i.v. were required to induce vascular protein leakage in different organs. This response was blocked by pretreatment with H1 and H2 receptor antagonists, but only slightly reduced after systemic capsaicin pretreatment of guinea-pigs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibition of compound 48/80--induced vascular protein leakage by pretreatment with capsaicin and a substance P antagonist. 608 60

The influence of serotonin (5-hydroxytryptamine, 5-HT) on human ureteral smooth muscle was explored in a series of in vitro experiments. 5-HT evoked a dose-dependent contraction of the ureter. The effect of 5-HT was unaltered by blockade of 5HT3 and 5HT4 receptors and muscarinic cholinergic receptors. The 5HT2 receptor antagonist ketanserin (KT; 10(-5)-10(-4) M) and mixed 5HT1/5HT2 receptor antagonist methysergide (MS; 5 x 10(-5) M) inhibited the effect of 5-HT. Since the antagonist dissociation constant at 5HT2 receptors for both KT and MS is found to be approximately 10(-9) M, it is concluded that this contractile effect may have been mediated by some other, as yet uncharacterized 5-HT receptor. We believe that 5-HT is a potential neurotransmitter in the human upper ureteral smooth muscle.
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PMID:Influence of serotonin on the human ureter: an in vitro pharmacological study. 858 66

1. The influence of 5-hydroxytryptamine (5-HT) receptor agonists and antagonists on the ureter motility was investigated in vivo on intact ureters of anaesthetized pigs. Drugs were administered intravenously or topically. 2. 5-HT induced a dose-dependent increase in the frequency of ureter contractions in anaesthetized pigs when given intravenously (0.0001-1 mg kg(-1); ED(50) 0.066 mg kg(-1)) or topically (0.001-1 mg ml(-1); EC(50) 0.043 mg ml(-1)). Significant increases in heart rate and blood pressure were observed when the drug was given intravenously but not topically. 3. The 5-HT(2A) agonist, DOI (1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane) increased the frequency of ureteral contractions in a dose-dependent manner (1-300 microg kg(-1) i.v.). Calculation of ED(50) indicated this compound to be about 1.5 times more potent with an efficacy of 23% compared to 5-HT. 4. The 5-HT(2A/2C) antagonist, ketanserin (0.5 mg kg(-1)) and the 5-HT(2C) antagonist, methysergide (1 mg kg(-1)) antagonized the 5-HT-induced ureter peristalsis when given intravenously. Contraction amplitude, blood pressure and heart rate were not affected by the antagonists. 5. Intravenous (0.0001-1 mg kg(-1)) and topical (0.0001-1 microg ml(-1)) ketanserin significantly decreased the frequency of spontaneous ureteral contractions to about 30% of controls, which could be partly reversed by 5-HT (0.3 mg kg(-1) i.v.). The contraction amplitude, contractions of the contralateral, saline perfused ureter, heart rate and mean arterial blood pressure were not affected. 6. Thus, contractility of porcine ureter is mediated by 5-HT(2) receptors. Their antagonists ketanserin and methysergide seem to be promising drugs for treatment of acute ureteric colic or in preparing the ureter for ureteroscopy.
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PMID:Effects of ketanserin and DOI on spontaneous and 5-HT-evoked peristalsis of the pig ureter in vivo. 1186 31

1 This study was designed to investigate the effect of 5-hydroxytryptamine (5-HT) and to characterize the 5-HT receptors involved in 5-HT responses in the pig intravesical ureter. 2 5-HT (0.01-10 microM) concentration-dependently increased the tone of intravesical ureteral strips, whereas the increases in phasic contractions were concentration-independent. The 5-HT(2) receptor agonist alpha-methyl 5-HT, mimicked the effect on tone whereas weak or no response was obtained with 5-CT, 8-OH-DPAT, m-chlorophenylbiguanide and RS 67333, 5-HT(1), 5-HT(1A), 5-HT(3) and 5-HT(4) receptor agonists, respectively. 5-HT did not induce relaxation of U46619-contracted ureteral preparations. Pargyline (100 microM), a monoaminooxidase A/B activity inhibitor, produced leftward displacements of the concentration-response curves for 5-HT. 3 5-HT-induced tone was reduced by the 5-HT(2) and 5-HT(2A) receptor antagonists ritanserine (0.1 microM) and spiperone (0.2 microM), respectively. However, 5-HT contraction was not antagonized by cyanopindolol (2 microM), SDZ-SER 082 (1 microM), Y-25130 (1 microM) and GR 113808 (0.1 microM), which are respectively, 5-HT(1A/1B), 5-HT(2B/2C), 5-HT(3), and 5-HT(4) selective receptor antagonists. 4 Removal of the urothelium did not modify 5-HT-induced contractions. Blockade of neuronal voltage-activated sodium channels, alpha-adrenergic receptors and adrenergic neurotransmission with tetrodotoxin (1 microM), phentolamine (0.3 microM) and guanethidine (10 microM), respectively, reduced the contractions to 5-HT. However, physostigmine (1 microM), atropine (0.1 microM) and suramin (30 microM), inhibitors of cholinesterase activity, muscarinic- and purinergic P(2)-receptors, respectively, failed to modify the contractions to 5-HT. 5 These results suggest that 5-HT increases the tone of the pig intravesical ureter through 5-HT(2A) receptors located at the smooth muscle. Part of the 5-HT contraction is indirectly mediated via noradrenaline release from sympathetic nerves.
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PMID:Characterization of the 5-hydroxytryptamine receptors mediating contraction in the pig isolated intravesical ureter. 1252 83

High levels of various uremic toxins such as guanidino compounds and advanced glycation endproducts, as well as an excess of parathyroid hormones, are involved in the pathogenesis of acute uremic encephalopathy. Moreover, distant effects of the damaged kidney with enhanced production of inflammatory mediators are implicated. Data on the pump activity of an abnormal Na-K-ATPase and inhibition of the organic anion transporter system in the brain have been published previously. Recently, the effect of an experimentally induced acute renal failure (ARF) on the neuronal cell activation of Fos and Fra-2 in the rat brain was investigated by immunohistochemistry. ARF was induced by using the following 3 rat models: bilateral nephrectomy, bilateral ureter ligation, and uranyl acetate injection with corresponding controls. The Fos and the Fra-2 immunoreactive neurons of the brain were determined in a total of 120 brain areas over a period of 3 days post bilateral nephrectomy and bilateral ureter ligation and 12 days after uranyl acetate. An activation response was observed in 73 of 120 areas of the brain. The responses were classified into 4 groups: (1) biogenic amines (noradrenaline, adrenaline, histamine, and 5-hydroxytryptamine), (2) stress-sensitive forebrain areas, (3) neuronal cell groups involved in the regulation of water and electrolyte homeostasis, and (4) central autonomic cell groups. In the uranyl acetate-induced ARF, activation of Fos and Fra-2 immunoreactivity took place at the earliest time-point (3 hours) which persisted even after improvement of ARF. This suggests the involvement of the toxic effects of uranium as a result of its accumulation in the brain.
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PMID:Mechanisms of acute uremic encephalopathy: early activation of Fos and Fra-2 gene products in different nuclei/areas of the rat brain. 2079 70