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)

Adenylate cyclase and phosphodiesterase enzyme activities were demonstrated in rabbit ureter. NaF, 10 mM, caused a 60.9 per cent increase in adenylate cyclase activity. Isoproterenol, 5 X 10-7 to 10-5 M induced a statistically significant dose-dependent increase in adenylate cyclase activity which was suppressed by propranolol, 10-7 M. Theophylline, 5 X 10-5 to 10-2 M, significantly inhibited phosphodiesterase activity. Thus, isoproterenol and theophylline, two agents that can relax ureteral segments previously contracted by a depolarizing concentration of potassium, could presumably increase cyclic AMP levels, isoproterenol by increasing synthesis and theophylline by decreasing degradation.
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PMID:Adenylate cyclase and phosphodiesterase activity in rabbit ureter. 19 62

To determine whether the ureter is innervated by the autonomic nervous system, isolated canine ureters were superfused with modified Tyrode solution, and force developed in response to 100-msec duration stimuli at a rate of 3 per min was monitored. Norepinephrine and phenylephrine significantly increased developed force; the latter more than the former. These increases in developed force were blocked by phentolamine, and propranolol enhanced the stimulatory effect of norepinephrine. In the presence of phentolamine, norepinephrine significantly decreased developed force. Isoproterenol significantly decreased developed force and this significant decrease in contractility was not observed in the presence of propranolol. High intensity, high frequency, short duration stimuli which in themselves were unable to excite quiescent rabbit and canine ureteral segments potentiated contractile force of segments contracting at the basal rate of 3 per min in response to long duration stimuli. When these same high intensity, high frequency, short duration stimuli were applied to ureteral segments pretreated with phentolamine, the developed force of the basally driven preparations decreased. These data suggest the presence of alpha-stimulatory and beta-inhibitory adrenergic receptors in canine and rabbit ureter and provide evidence for adrenergic tissue within the wall of the ureter that can influence contractile force.
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PMID:Adrenergic innervation of the ureter. 71 4

1. The ionic mechanism of the excitatory action of catecholamines and histamine on the smooth muscle cells of guinea-pig ureter was studied with the double sucrose-gap method. 2. In normal conditions adrenaline and noradrenaline in a concentration of 10(-5) g/ml., and histamine in a concentration of 10(-6) g/ml., prolonged the duration of the plateau of the action potential and increased the amplitude and duration of the phasic contraction. Sometimes these changes were accompanied by a slight depolarization of the muscle membrane and by a small increase (with noradrenaline) or decrease (with histamine) of the membrane resistance. The amplitude and duration of the fast spike component of the action potential were not changed. 3. Isoprenaline in a concentration of 10(-5) g/ml. either caused no change or it decreased the duration of the plateau, reduced the amplitude of contractions and reduced excitability. 4. Tetraethyl ammonium (TEA; 5 mM), which blocks the delayed outward K current, did not prevent the increase in the duration of the plateau nor the increase of the amplitude and duration of the contractions by noradrenaline and histamine. 5. In Na-free or in K-free solution or in the presence of ouabain, i.e. in conditions in which the Na-gradient across the membrane was reduced, noradrenaline and histamine were unable to increase the duration of the plateau and the amplitude and duration of the contraction. 6. In the presence of Mn2+ (2 mM) which suppressed the spike component of tha action potential and the phasic contraction, theeffects of noradrenaline and histamine were almost abolished. 7. The results suggest a dual ionic mechanism of the alpha-action of catecholamines and of the action of histamine on the smooth muscle of ureter: (1) these drugs affect the passive ionic permeability of the membrane in a manner that results in depolarization; (2) they specifically activate the potential-dependent conductance of the slow Na channels, thereby increasing the plateau duration. The increased amplitude and duration of the contraction is the result of their primary effect on the plateau of the action potential.
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PMID:The mechanism of the excitatory action of catecholamines and histamine on the smooth muscle of guinea-pig ureter. 84 27

1. We have studied the effects of alpha- and beta-adrenoceptor agonists and antagonists on both phasic peristaltic activity and basal tone of the isolated intravesical ureter of the pig by means of isometric techniques in vitro. 2. Spontaneous phasic activity was exhibited by 21% of pig intravesical ureter preparations manifested as rhythmic contractions with average frequency and amplitude of 2.54 +/- 0.18 min-1 and 1.48 +/- 0.16 g (n = 31), respectively. 3. Adrenaline, noradrenaline and phenylephrine induced concentration-dependent increases in both phasic activity and basal tone of ureteral preparations, all three agonists being more potent in modifying ureteral phasic activity than baseline tone. B-HT 920, B-HT 933 and clonidine had no significant effect. 4. Phentolamine (10(-9)-10(-7) M) and prazosin (3 x 10(-11)-3 x 10(-8) M) significantly inhibited increases in both frequency of phasic activity and baseline tone induced by a submaximal dose of noradrenaline. Rauwolscine (10(-9)-10(-7) M) affected only the tone evoked by noradrenaline and higher concentrations of this antagonist were needed to block phasic activity. 5. Pretreatment of ureteral strips with the beta-adrenoceptor antagonist, propranolol (10(-6) M), significantly increased the maximum contraction evoked by noradrenaline. After incubation with phentolamine (10(-6) M), noradrenaline (10(-7)-10(-6) M) decreased phasic activity induced by prostaglandin F2 alpha (10(-5) M). Isoprenaline and salbutamol also abolished PGF2 alpha-induced phasic activity. Pafenolol (10(-6) M) and butoxamine (10(-6) M) blocked the inhibitory effect of noradrenaline, isoprenaline, and salbutamol on PGF2 alpha-induced phasic activity. 6. These results suggest that noradrenaline may modulate both phasic peristaltic activity and basal tone of pig intravesical ureter through both alpha- and beta-adrenoceptors.
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PMID:Noradrenaline modulates smooth muscle activity of the isolated intravesical ureter of the pig through different types of adrenoceptors. 136 2

Blind ending bifid ureter is a rare anomaly in the urinary tract. This anomaly may result from failure of a premature branch of the ureteral bud to join with the metanephric blastema. A 21-year-old man was admitted with macroscopic hematuria and colic pain in the left flank region. Urinalysis demonstrated hematopyuria and excretory urography suggested bifid ending accessory ureter with a stone on the left side. Surgical exploration showed that the accessory ureter was bifurcated from the left ureter at about 5 mm from the bladder wall and ran parallel with the left ureter. Although dense adhesions to the surrounding tissue existed, the accessory ureter was resected at the site of the junction. It measured 3 cm in length and 1 cm in greatest diameter. The stone found at the tip of the accessory ureter was composed of calcium oxalate (24%) and calcium phosphate (76%). Histological examination revealed that the ureter had all layers of normal ureteral structure and no renal tissue was identified in the specimen resected. During a follow-up period of 22 months after the operation, he was free of urinary tract infection and abdominal pain. Of 77 cases with blind ending bifid ureter reported in the Japanese literature, a ureteral stone was found in the blind branch in only 5 cases.
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PMID:[Blind ending bifid ureter with stone in the blind branch: report of a case]. 185 88

A 21-month-old girl presented with ureteral triplication, representing an exceptional variant of Smith's type 1. One ureter was intravesical and the other 2 were extravesical (bladder neck and vaginal).
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PMID:Ureteral triplication: double extravesical ureteral ectopia. 198 66

The presence of both alpha and beta adrenergic receptors in the caudal third ureter of the horse were studied in vitro under isometric conditions using adrenergic agonist and antagonist drugs. Isoprenaline and the beta 2- stimulating agent, salbutamol, elicited relaxation of the ureter smooth muscle strips. The responses were not affected by the beta 1- blocking agent, practolol, but were totally abolished by propranolol and the beta 2- blocking agent, butoxamine. The stimulation of alpha-adrenergic receptors with noradrenaline and phenylephrine evoked a contractile effect which was totally inhibited by phenoxybenzamine and the alpha 1- blocking agent, prazosin. It is concluded that in the horse ureter the alpha receptors are dominant and belong to alpha 1 subtype while the beta receptors are recessive and belong to beta 2- adrenoceptor subtype.
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PMID:Alpha- and beta-adrenergic receptors in the horse ureter. 283 3

Resistance to fluid flow in the canine ureter can be divided into two categories. The higher resistance is recorded at flow rates less than or equal to 2.16 ml./min. At these rates the ureter is able to completely coapt its walls so that urine is transported in individual boluses. The lower resistance is recorded at flow rates greater than or equal to 5.40 ml./min. At these rates the ureteral walls remained open and urine is transported as a column of fluid. Noradrenaline causes a marked increase in ureteral resistance at low flow rates and a small but statistically significant increase in ureteral resistance at high flow rates. Acetylcholine increases resistance only at the low flow rates. Isoproterenol significantly decreases resistance at both low and high flow rates. These findings are consistent with ureteral resistance to fluid flow being composed of two components. One is the ureteral peristaltic contraction which plays a principal role in urinary bolus transport at low flows; the other is ureteral wall tonus, which plays an important role in the transport of columns of urine by the ureter, which does not coapt its walls, at the higher flow rates.
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PMID:Effects of noradrenaline, isoproterenol and acetylcholine on ureteral resistance. 371 89

An experimental model which permits independent changes in ureteral peristalic frequency and bolus volume was employed to explore the effects of autonomic agonists on ureteral bolus volume, peristaltic frequency, intraluminal pressure and flow volume in the dog. Norepinephrine caused an increase in ureteral peristaltic frequency, an elevation in intraureteral baseline and contractile pressure and a decrease in bolus volume, with a resultant decrease in the rate of fluid transport. Isoproterenol caused a decrease in ureteral peristaltic frequency, and a fall in intraureteral baseline and contractile pressure, or it completely abolished peristalsis and bolus formation. These changes were accompanied by an increase in the rate of fluid transport. Acetylcholine caused an increase in ureteral peristaltic frequency, an elevation of intraureteral baseline pressure but no change in contractile pressure, and a small decrease in bolus volume with a resultant small decrease in the rate of fluid transport. These data suggest that the autonomic nervous system may affect urine transport through the ureter by not only regulating peristaltic frequency but also by influencing bolus volume.
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PMID:Ureteral urine transport: changes in bolus volume, peristaltic frequency, intraluminal pressure and volume of flow resulting from autonomic drugs. 379 56

Isoproterenol produced a concentration-dependent increase in contractile force of rabbit upper renal pelvic smooth muscle. Conversely, isoproterenol produced a concentration-dependent decrease in contractile force of rabbit lower renal pelvic smooth muscle. These data show that in response to isoproterenol upper renal pelvic smooth muscle, which is thought to act as a pacemaker region for pelviureteral peristalsis, resembles cardic muscles, whereas lower pelvic smooth muscle is similar to ureter and other smooth muscles.
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PMID:Effect of isoproterenol on contractile force of isolated rabbit renal pelvic smooth muscle. 408 74


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