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

Like human kininogens-deficiency, the ureter urine of Brown Norway (B/N) Katholiek rat, a congenitally deficient strain in plasma high molecular weight (HMW)- and low molecular weight (LMW)-kininogen, showed no detectable kinin in the peptide fraction of gel chromatography, whereas normal ureter urine (B/N-Kitasato rat) expressed kinin in the peptide fraction, when assayed by bradykinin enzyme immunoassay (EIA). However there was immunoreactive substance in the higher molecular weight fraction in both strains of rat. The nature of this substance is not known, but it may give rise to a wrong estimate for kinin if rat urine is allowed to immunoassay directly, and peptide fraction of urine is not resolved into its components by gel chromatography. Kinin degrading activity in rat urine is so potent that kinin could be mostly degraded when stored in the bladder, since kinin was found in the peptide fraction of fresh ureter urine but not in that of bladder urine of the normal strain.
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PMID:Differentiation of kinin fractions in ureter urine and bladder urine of normal and kininogen-deficient rats. 268 78

Recent experiments have shown that 1,25-dihydroxyvitamin D3-like material is produced in cultured nonrenal cells and may be present in the sera of anephric patients. We reexamined the question of whether 1,25-dihydroxyvitamin D3 can be synthesized extrarenally in the rat in vivo. To intact, sham-operated, ureter-ligated, or acutely nephrectomized vitamin D-deficient rats raised on a diet normal in calcium and phosphorus, we gave a physiologic dose of high-specific-activity 25-hydroxy-[3H]vitamin D3 (3.6-3.8 microCi; approximately equal to 25 pmol per rat). Twenty-four hours later we examined their tissues and plasma for the presence of radiolabeled 1,25-dihydroxyvitamin D3. Large amounts of radioactivity that behaved chromatographically as identical with authentic 1,25-dihydroxyvitamin D3 were present in the plasma, bone, and intestine of the intact, sham-operated, or ureter-ligated rats. However, no radioactivity eluting in a manner similar to 1,25-dihydroxyvitamin D3 was found in plasma, bone, or intestine of acutely nephrectomized rats. We conclude that, in the acutely nephrectomized living rat, 1,25-dihydroxyvitamin D3 is not present in plasma, bone, or intestine in quantities detectable by the sensitive techniques we have used. No conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 was observed during a 24-hr period after nephrectomy of vitamin D-deprived rats. This fact casts doubt upon the significance of the in vitro production of 1,25-dihydroxyvitamin D3 by nonrenal cells as an in vivo phenomenon.
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PMID:Do tissues other than the kidney produce 1,25-dihydroxyvitamin D3 in vivo? A reexamination. 657 38

Several animals have been used as models for experimental upper urinary tract surgery. Although minipigs have recently gained favor because their upper urinary tract is grossly similar to that of humans, the ureteral microanatomic features of the two species have not been compared. We evaluated the histologic features of human and animal ureters in order to provide addition information regarding experimental models for upper urinary tract surgery. Cross-sections of upper, middle, and lower ureteral segments from human autopsy specimens and animals (farm pig, minipig, dog, sheep, rabbit, and rat) were evaluated after preparation with Masson's trichrome stain. Morphology, computer-assisted morphometry, linear micrometry, and point-count estimation of smooth muscle/connective tissue ratios were assessed. The epithelium was remarkably consistent across all species, both morphologically and in terms of absolute size. The lamina propria was highly vascularized in all species, but the compactness varied with the overall ureteral dimensions. In the muscularis, the relative size and the percentage composed of smooth muscle differed widely among species, as did the ratio of muscularis to lamina propria cross-sectional surface area. Among the species evaluated, the sheep, farm pig, and minipig ureters were the best histologic approximations of the human ureter. Given the difficulties with manipulation of the small sheep ureter, the minipig and farm pig models appear to be optimal for experimental research on upper urinary tract surgery by an endourologic approach.
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PMID:Comparative ureteral microanatomy. 897 86