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

We report a third case of 2, 8-dihydroxyadenine stones in a child with a complete lack of the adenine salvage enzyme--adenine phosphoribosyltransferase (APRT). The propositus, a 20-month-old girl of consanguineous Arab parents, presented with multiple urinary tract infections and supposed 'uric acid' stones in the right renal pelvis and left ureter. Both parents and one brother were heterzygotes for the defect, in keeping with an autosomal recessive mode of inheritance. In contrast with the other purine salvage enzyme disorder of childhood with true uric acid stones (the Lesch-Nyhan syndrome), uric acid excretion was normal in all family members. As in our previous case, treatment with allopurinol, without alkali, has eliminated the urinary excretion of 2, 8-dihydroxyadenine: the stones were removed surgically. 2, 8-Dihydroxyadenine should be considered in any child thought to have uric acid stones and tests made to distinguish the two compounds.
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PMID:Complete deficiency of adenine phosphoribosyltransferase: a third case presenting as renal stones in a young child. 42 May 19

A 37-year old female was admitted with a complaint of gross hematuria. Intravenous pyelography and retrograde pyelography showed right non-functioning kidney with a radiolucent stone in the ureter. Computerized tomographic scan revealed right hydronephrosis and ureteral stone. Ureterolithotomy was performed. Infrared spectrometric analysis of the stone revealed a 2,8-dihydroxyadenine calculus. The adenine phosphoribosyltransferase activity in red blood cells was partially deficient. After the operation the patient has been given 100 mg/day of allopurinol and is on a low purine diet. There have been no signs of recurrence.
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PMID:[A case of 2,8-dihydroxyadenine stone with a partial deficiency of adenine phosphoribosyltransferase]. 240 67

Prostaglandins of the E type (PGE) relaxed guinea-pig ureter but prostaglandins of the F type (PGF) did not affect smooth muscle contraction. Hyperpolarization and relaxation of the muscle cells caused by the PGEs were achieved at concentrations in a different range, a feature also observed in the presence of forskolin or iso-butyl-methyl-xanthine (IBMX). Hyperpolarization was inhibited in the presence of k-strophanthoside. The c-AMP content of ureter smooth muscle cells was increased in the presence of PGE2. These observations suggest that the PGE-induced hyperpolarization is caused by activation of the sodium-potassium pump and that enhancement of the cellular c-AMP level plays a major role in the PGE-induced relaxation.
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PMID:The action of prostaglandins on ureter smooth muscle of guinea-pig. 244 83

The renal excretion of prostaglandins E2 and 6-keto-F1 alpha, thromboxane B2 and cyclic adenosine 3', 5'-monophosphate was measured in a solitary kidney model of chronic ureteral obstruction in rabbits. The presence of obstruction was confirmed by intravenous pyelography. Growth rate of the animals and furosemide-stimulated diethylenetriaminepentaacetic acid renography were used to grade the obstruction. As correlated to urinary creatinine concentration the excretion of 6-keto-PGF1 alpha dominated in nephrectomized, unobstructed control animals. With the degree of ureteral obstruction becoming more severe, the output of PGE2 increased, while that of 6-keto-PGF1 alpha and TxB2 decreased. As a result the ratios PGE2/6-keto-PGF1 alpha and PGE2/TxB2 were three times as high in severely obstructed rabbits as in control animals. The renal output of cyclic AMP was unaffected by chronic obstruction. We conclude that the renal metabolism of prostanoids is affected in a unique way in chronic partial obstruction of the ureter.
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PMID:Renal excretion of prostanoids and cyclic AMP in chronic partial ureteral obstruction of the rabbit. 253 44

Cyclic AMP and cyclic GMP phosphodiesterase (PDE) activities and calmodulin levels were determined in ureters from guinea pigs of the following ages: 50 and 56 days fetuses, three, 10, 21, 50, and 90 days, and three years old. While there is little change in ureteral cyclic AMP-PDE with age, cyclic GMP-PDE increases with age. Activity of cyclic GMP-PDE in supernatants prepared from three-year-old guinea pig ureter homogenates is 462% and 216% higher than that from 50-day fetus and three-day animals, respectively. Calmodulin levels have a bimodal distribution with age; values are highest in supernatants from 10 and 21 day ureters, but also increase in the three-year ureters when compared to 50 and 90-day values.
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PMID:Ontogeny of cyclic AMP and cyclic GMP phosphodiesterase activities and of calmodulin levels in guinea pig ureter. 283 69

The hyperchloremic metabolic acidosis which can occur following urinary diversion through intestinal segments has been managed with bicarbonate or citrate salts. However, satisfactory management is not always possible with this form of treatment. The development of this acidosis has been attributed to intestinal reabsorption of urinary solutes or intestinal secretion of bicarbonate. Intestinal absorptive and secretory processes are modulated by an adenylate cyclase-cyclic AMP system. Chlorpromazine inhibits the effect of cyclic AMP on the intestinal mucosal cell. The use of chlorpromazine in the management of the hyperchloremic metabolic acidosis following urinary diversion was investigated. A canine model employing an ileal segment between ureter and bladder and a rat model in which urine is diverted through the entire colon have been developed. Chlorpromazine (5 mg./kg./day) was found to be efficacious in the management of the metabolic derangements that occur in both of these models. A case study is presented in which conventional management of this syndrome with bicarbonate salts was unsuccessful. The use of chlorpromazine as an adjuvant treatment allowed correction of the acidosis.
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PMID:Chlorpromazine: adjuvant therapy for the metabolic derangements created by urinary diversion through intestinal segments. 298 65

An electromyographic study of the responses of the pelviureter to dibutyryl cyclic AMP was performed using isolated canine pelviureteral preparations. Dibutyryl cyclic AMP caused a marked increase in the amplitude of discharge potential in the pelvicalyceal pacemaker region and this was associated with a decrease in renal pelvic pressure. The frequency of the pacemaker discharge did not increase. On the other hand, in the lower pelvis and ureter, dibutyryl cyclic AMP caused a small but significant decrease in the amplitude of discharge potentials and this was associated with a marked decrease in discharge frequencies in the lower pelvis and ureter.
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PMID:Effect of dibutyryl cyclic adenosine monophosphate on canine pelviureteral discharge potentials. 301 1

Research on the physiopathologic and biochemical nature of prostaglandins (PGs) suggest that PGs play a role in reproductive physiology. In vitro studies show that the PGE series decrease the motility of the human uterus, fallopian tubes, and ureter, and produce vasodilatation. PGFs cause vasoconstriction and increased motility of the uterus, fallopian tubes, ureter, and gastrointestinal muscle. PGs are also known to inhibit lipolysis, platelet aggregation, and gastric secretion. The exact mechanism of PGs are not fully understood, but evidence suggests that many responses can be attributed to interference with the enzyme adenyl cyclase, which catalyzes the formation of adenosine 3',5'-monophosphate (cyclic AMP) from adenosine triphosphate. The adenyl cyclase-cyclic AMP system mediates lipolysis, steroidogenesis, gastric secretion, certain smooth muscle motility responses, and increase in permeability due to vasopressin. Early studies of the myometrial effects of PGs showed that the PGE series inhibited the motility of the human myometrium in vitro while the PGF series produced mixed responses. The role of PGF2alpha in parturition has not been established but evidence suggests that it has a potential role as an oxytocic in cases of therapeutic abortion. In the area of human fertility, the physiologic role of PGs in seminal fluid is hypothesized to facilitate the migration of spermatozoa from the vagina into the uterine cavity. Karolinska Institute researchers have found that some infertile males have low PG levels in their ejaculates and are now working with methods of improving the PG levels to improve their fertility. Pickles et al. proposed a potential role for PGs in the etiology of dysmenorrhea, having found a significantly higher ratio of PGF to PGE in a series of patients with severe dysmenorrhea than in a comparable series of normal patients. The luteolytic and antinidatory effects of PGF2alpha are being investigated and studies appear encouraging. PGs have therapeutic potentials in induction of labor, treatment of infertility, morning-after conception, treatment of dysmenorrhea, and contraception by alteration of fallopian tube motility.
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PMID:The role of prostaglandins in reproductive physiology. 491 53

To determine the role of the autonomic nervous system and of cyclic AMP in the control of ureteral peristalsis, isolated guinea pig ureters were placed in a 20-ml organ bath containing modified Krebs solution. Theophylline induced significant dose-dependent reduction in frequency and amplitude of contractions of the ureter hypertonified with barium chloride. No change in frequency or amplitude of contractions was observed with isoproterenol. Besides, our data explain why beta-agonist drugs are of very little value in the treatment of renal colic due to spasms of the pelviureteral tract.
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PMID:Effects of theophylline and isoproterenol on the activity on the isolated guinea pig ureter. 609 6


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