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)

Previous studies have indicated that the effects of renal alpha-2 adrenoceptor stimulation are mediated through the blockade of the renal effects of vasopressin. If this premise is correct then 1) specific antagonists of the antidiuretic effect of vasopressin (V2 antagonists) should mimic alpha-2 adrenoceptor stimulation and 2) in the presence of V2 antagonists, the diuretic and natriuretic effect of clonidine should be attenuated. The renal effects of [d(CH2)5,D-Ile2,Ile4]AVP, a specific V2 antagonist, were studied. On the day of the experiment, uninephrectomized rats were anesthetized, and the carotid artery and jugular vein were cannulated for recording blood pressure and saline infusion, respectively. The left kidney was exposed and the ureter cannulated. A 31-gauge needle was advanced into the renal artery to permit direct i.r. infusion of study drugs. Bolus doses of the V2 antagonist (0, 1, 3, 10, or 30 nmol/kg i.v.) produced a dose-related increase in urine volume and free water clearance at all doses tested. Sodium excretion increased only at the higher doses (10 and 30 nmol/kg). This dose-related dissociation in water and then sodium excretion is similar to that observed after i.r. clonidine infusions. In the presence of the V2 antagonist, clonidine (3 micrograms/kg/min) had no effect on urine volume or free water clearance but significantly decreased the excretion of sodium from control. These results demonstrate that V2 antagonists mimic the effects of i.r. clonidine. As well, in the absence of vasopressin (V2 antagonism), the effects of clonidine are attenuated. Moreover, they are also consistent with not only an antidiuretic role for endogenous vasopressin but also an antinatriuretic one.
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PMID:Role of vasopressin in response to intrarenal infusions of alpha-2 adrenoceptor agonists. 197 99

To prevent their collapse, a certain amount of stiffness is generally required for prosthetic venous grafts, so EPTFE grafts have been used. However, the native vein is pliable without any stiffness. We developed a soft and pliable graft that can maintain patency of the lumen because of its compliance. Fresh porcine ureter was incubated in a ficin solution to remove cell components and noncollagenous proteins. One percent protamine sulfate solution was injected into the ureter lumen to impregnate the inner surface. The ureter was then crosslinked with a 1% glutaraldehyde solution, dipped into a 1% heparin solution for 5 hours, and rinsed with distilled water. This procedure made the ureter very soft and pliable, and also conferred antithrombogenicity to the graft by heparinization. The grafts were implanted into the posterior vena cavae of 20 dogs and were removed from 1 to 878 days after implantation. Eighteen grafts were patent, but two grafts were occluded at the anastomotic site at 218 and 107 days, respectively. As a control experiment, nonheparinized grafts were implanted into 15 dogs; all were occluded with fresh thrombi. All the patent grafts kept their original elasticity, which allowed them to heave in unison with the heartbeat, and were similar in appearance to the native vena cava. Heparinization was effective in preventing thrombus formation. These results indicate that this type of graft is an ideal prosthesis as a venous graft, having physiologic properties such as compliance and antithrombogenicity.
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PMID:Development of a soft, pliable, slow heparin release venous graft. 225 94

Similar to mammals, kidneys of domestic fowl undergo compensatory hypertrophy after loss of functional renal mass. Because this species continues to develop new nephrons for up to 12-wk posthatch, renal hyperplasia might play a significant role in compensatory growth. Either transient or permanent loss of approximately 60% of the right kidney was produced in 2- to 3-wk-old roosters by simple ureteral transection or by removing a 1-mm segment of ureter at the level of the ischiadic artery, respectively. In the latter (experimental) group, right anterior and medial divisions atrophied leaving only the posterior division intact. Spontaneous reanastomosis occurred in the former (reconnected) group, and all three divisions were present at death. Control birds were untouched as were the left kidneys of experimental and reconnected birds. At 40-50 wk, renal function was measured separately in right and left kidneys of all groups during five different infusion protocols. Compared with control kidneys, experimental kidneys had a 50-60% weight gain, and their glomerular size distribution profile was shifted to the right (larger glomeruli). Reconnected kidneys were not hypertrophied, and their profile was shifted to the left (smaller glomeruli). Neither group had significant formation of new nephrons. Once variations in kidney weight were taken into account, there were no differences between hypertrophied (experimental) and control kidneys in urine flow rate (UFR), glomerular filtration rate (GFR), paraaminohippuric acid (PAH) clearance, UFR/GFR, urine osmolality, urine/plasma osmolality, osmolal clearance, free water clearance, Na and K load, absolute Na and K excretion, and fractional Na and K excretion except as follows: 1) during infusion of isotonic mannitol-dextrose at 0.1 ml.min-1.kg body wt-1 experimental kidneys had a lower fractional excretion of K than control kidneys, and 2) during brisk osmotic diuresis (isotonic mannitol-dextrose at 0.4 ml.min-1.kg body wt-1) experimental kidneys had higher UFR and free water clearance and lower urine osmolality and urine/plasma osmolality than control kidneys. Reconnected kidneys differed from control kidneys in only 1 of 210 comparisons. Permanent loss of functional renal mass in young birds produces significant compensatory renal hypertrophy that is due to enlargement of existing nephrons rather than formation of new nephrons. Hypertrophied kidneys function like normal kidneys except under conditions of brisk osmotic diuresis.
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PMID:Morphological and functional comparisons of normal and hypertrophied kidneys of adult domestic fowl (Gallus gallus). 230 94

In June 1988, the new type of the lithotripter MPL 9000 (Dornier), which was the first interdisciplinary lithotripter for treatment of urinary and biliary calculi, was installed at the Shakai Hoken Chukyo Hospital. MPL 9000 has some features which enable one to treat with low range of shock wave energy and without anesthesia due to the enlarged aperture of the ellipsoid (210 mm), and locate the stone by computerized two ultrasound probes (coaxial, lateral). Unlike HM-3, the water bath is not used: shock wave is shot through the water cushion. From June to November 1988, 35 patients suffering from 64 urinary calculi were treated. The majority represented caliceal (75%) and pelvic (17%) stones, whereas 5 calculi were treated in the upper and lower ureter. Twenty-four patients were treated in one session and 11 patients needed additional sessions. The given number of shock waves was between 1337 and 3050 per one session and averaged 2403 with low generator voltage (15-18 kv). Twenty sessions (42%) were given without any medication and other 28 sessions (58%) were under analgesia (Pentazocine, i.v.) for the pain complained during the treatment. The rate of successful disintegration (less than 5 mm) was 88%. After the 1-month followup, 47.1% were free of stone, and 62.1% were free after the 3-month. Four patients had arrhythmia and one patient was with a subcapsular renal hematoma. We have concluded that this lithotripter is useful to treat upper and lower urinary tract calculi, in particular radiolucent ones in high risk patients because it is applicable without anesthesia.
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PMID:[Clinical experience with ESWL with new Dornier lithotripter MPL 9000]. 232 21

The occurrence of tachykinins in sensory neurons of the guinea-pig was studied by means of radioimmunoassay combined with ion-exchange and high-performance liquid chromatography as well as by immunohistochemistry. Antisera raised against kassinin (antiserum K12), neurokinin A (NKA) (antiserum NKA2) and substance P (SP) (antisera SP25 and SP2) were used. Antiserum K12 detected NKA, neuropeptide K (NPK) and a component eluting in the position of eledoisin (ELE) in extracts of the lung and ureter. Neurokinin B (NKB) was, however, not found. Neutral water extraction favored recovery of NKA and of the ELE-like component, while NPK was found only in acid extracts. The SP antisera detected two immunoreactive components of which the major form coeluted with synthetic SP. Capsaicin pretreatment depleted all these various forms of immunoreactivity in several peripheral organs including the ureter and lung. The immunoreactivity detected by antisera K12 or SP25 in radioimmunoassay had a similar regional distribution pattern in peripheral tissues. Immunohistochemical examination revealed that antiserum NKA2 stained the same spinal ganglion cells as the SP2 antiserum. The distribution of capsaicin-sensitive nerve fibers stained by these two antisera was also identical in peripheral organs such as the ureter, inferior mesenteric ganglion, heart and lung. It is concluded that multiple tachykinins, including SP, NKA, NPK and an ELE-like peptide, are present in capsaicin-sensitive sensory nerves in the guinea-pig. This finding can most likely be related to the origin of SP, NKA and NPK from the same precursor molecule, subsequent posttranslational tissue processing and axonal transport to terminal regions.
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PMID:Multiple tachykinins (neurokinin A, neuropeptide K and substance P) in capsaicin-sensitive sensory neurons in the guinea-pig. 241 71

Antidromic stimulation of sensory nerves or administration of capsaicin and SP in the guinea-pig induced vascular protein leakage with a similar pattern of distribution in different peripheral organs, characterized by a wide-spread but highly selective occurrence. The protein-extravasation responses in the tissues, following nerve stimulation or i.v. capsaicin, were highly correlated with the concentration of SP-LI. Systemic capsaicin treatment caused an almost total loss of SP-LI in visceral organs, in which the extravasation responses to capsaicin or nerve stimulation were also abolished. The ureter of the guinea-pig was most densely innervated by capsaicin-sensitive sensory nerves, which arrive at the rostral part of the ureter via the inferior mesenteric ganglion. The caudal ureter was mainly innervated from the pelvic nerves. The vascular permeability increase induced by SP or capsaicin was more pronounced in the ureter than in any other organ investigated. SP-LI, TK-LI and CGRP-LI coexist in sensory neurons of the guinea-pig and man, as shown by immunohistochemistry. These three kinds of immunoreactivity were found in sensory cell bodies with similar regional and terminal distribution patterns in both the central and peripheral areas. Systemic capsaicin treatment induced marked reduction of SP- and TK-LI in peripheral organs except for the ileum. CGRP-LI in the ureter was also sensitive to the capsaicin treatment. Characterization of the TK-LI (K12) of the guinea-pig ureter and lung, using ion-exchange chromatography and HPLC, demonstrated that at least three immunoreactive components corresponding to NKA, NPK and ELE were present. The major form of SP-LI eluted in the same position as synthetic SP. The NKA- and ELE-like components were also identified by HPLC in water extracts of human ureter. NKB was not detectable in the sensory neurons of the guinea-pig. Capsaicin caused an acute release of SP-, NKA- and ELE-like components from superfused slices of both the spinal cord and ureter of the guinea-pig in vitro. The release of tachykinins by capsaicin was calcium-dependent but tetrodotoxin-resistant. No detectable release of NKB- or NPK-LI was induced by capsaicin. Tachykinins share a common spectrum of biological activities with regard to hypotension, bronchoconstriction and protein extravasation when given systemically to guinea-pigs. The potency of the hypotensive action of tachykinins was similar. NKA and NPK evoked much stronger bronchoconstrictor effects than SP, while SP was more active than NKA in inducing vascular permeability changes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Tachykinins and calcitonin gene-related peptide in relation to peripheral functions of capsaicin-sensitive sensory neurons. 243 Apr 27

Rats with mammillary electrolytic lesions show a strong polydipsia and polyuria. This over-consumption may be primary or secondary to the polyuric effect. In this regard, mammillary lesioned rats excrete a greater amount of urine compared with control animals when matched in daily water consumption (partial water deprivation). Moreover, this abnormal water intake is significantly reversed by treatment with Pitressin, a vasopressin analogue. These results suggest that the polydipsia may be determined by the urinary water loss. However, when subjected to the bilateral ureter ligation, the experimental animals still outdrink the control ones, thus also suggesting a primary component of the polydipsia under study. The possible explanation of these components in relation to the mammillary polydipsia is discussed.
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PMID:[Primary/secondary characteristics of polydipsia induced by electrolytic lesion of the mammillary bodies]. 250 36

The spa treatment most widely used in the management of renal calculosis is the drinking of a certain amount of mineral water under certain predetermined conditions of temperature, time and rhythm. These treatments are always indicated unless there are obstacles to the passage of urine or general contraindications. Chances for success are increased if the diagnosis is exact and the stone has been located. The results obtained by various authors are reported and their statistical validity is discussed. Favorable effects consist in: increased diuresis with urine dilution and correspondingly reduced concentration of lithogenic salts and hence supersaturation of urine; reduced concentration of microorganisms; changes in the physiological condition of the renal medulla; changes in inhibitors of crystallization, in urinary pH; mechanical effect on the urinary passages; increased ureter motility; expulsion of small stones and sand; preventive action on recurrences after surgery and after extra-corporeal shock-wave treatment, percutaneous therapy and uretero-nephroscopy.
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PMID:[Hydrological therapy of renal lithiasis]. 253 86

The purpose of this investigation was to determine if the pharmacodynamics of the central nervous system stimulant pentylenetetrazol (PTZ) are altered in renal dysfunction. Female rats subjected to bilateral ureteral ligation (with sham-operated controls) or injected with uranyl nitrate (with saline injected controls) were infused intravenously with PTZ until the onset of either a minimal (myoclonic jerk) or maximal (tonic hindlimb extension) seizure. Neither chemically nor surgically induced renal dysfunction caused a change in the concentrations of PTZ in CSF, serum, or brain at onset of minimal seizures. When PTZ was infused to onset of maximal seizures, the rats with chemically induced renal dysfunction required higher concentrations, whereas the ureter-ligated rats convulsed at lower concentrations of PTZ than did the corresponding control animals. Thus, the effects of experimental renal dysfunction on the convulsant action of PTZ are dependent on both the disease model and the endpoint used for the pharmacodynamic measurement. Apparently, renal dysfunction did not affect the PTZ-induced seizure threshold, but inhibited the spread of seizures. The increased sensitivity of ureter-ligated rats may be due to their pronounced retention of water, since water loading is known to increase seizure susceptibility.
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PMID:Kinetics of drug action in disease states. XXXIII: Disparate effects of pentylenetetrazol in rats as a function of renal disease model and pharmacologic endpoint. 271 36

The prospective study was performed to reassess the necessity of water deprivation before excretory urography (IVP) with non-ionic contrast medium. 35 adults were deprived of water before IVP and divided into two groups. First group was received 250 ml 5% glucose solution and lopamidol-300 (1 ml/kg, maximum dose; 50 ml). Second group received contrast medium only. Image quality of IVP of the two groups were compared. In the first group the visualization of ureter and bladder were better than the second group. There was no significant difference in the caliceal and pelvic visualization between the two groups. Water deprivation was suggested to be unnecessary in IVP with non-ionic contrast medium.
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PMID:[Excretory urography with non-ionic contrast medium; clinical reassessment of the necessity of water deprivation]. 275 19


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