Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0403608 (ureter)
 9,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the capacity and the localization of N-acetylation of the mercapturic acid precursor S-benzyl-L-cysteine (BC), as well as the tubular reabsorption of this compound in the rat kidney in vivo et situ by renal clearance and continuous microinfusion and microperfusion experiments. In renal clearance experiments. 450 mumol BC was infused intravenously for 180 min. During the time of BC infusion and the following 180 min, the two kidneys excreted 400 mumol or 90% of the infused BC dose as the mercapturate N-acetyl-S-benzyl-L-cysteine (AcBC). Comparison of the amounts of BC and AcBC entering the left kidney via the renal artery with those leaving it via the renal vein and the ureter showed that 0.13 +/- 0.04 mumol BC/min (mean +/- SEM) was extracted and 0.24 +/- 0.08 mumol AcBC/min was formed by one kidney. The intrarenal acetylation can account for the formation of 38% of the mercapturate excreted in the final urine. In additional experiments, 50 pmol/min [14C]BC was microinfused into single superficial tubules at three different sites. During microinfusion into early proximal tubules, the final urine contained 16.3 +/- 1.8% of the microinfused radioactivity as AcBC, but no BC. When [14C]BC was microinfused into late proximal tubules, 13.0 +/- 2.3% of the infused label was recovered as BC, 28.1 +/- 2.3% as AcBC. During microinfusion into early distal tubules, the final urine contained no AcBC, but 90.3 +/- 2.1% of the infused [14C]BC was recovered.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Localization and capacity of the last step of mercapturic acid biosynthesis and the reabsorption and acetylation of cysteine S-conjugates in the rat kidney. 201 74

Six anesthetized 2- to 21-d-old male Guernsey calves weighing 28 to 61 kg were used in experiments in which either the left kidney was perfused, via the left renal artery, or the left ureter was perfused with metabolites of propachlor (2-chloro-N-acetylacetanilide, a herbicide). The glutathione conjugate of propachlor (2-S-glutathionyl-N-acetylacetanilide) was metabolized by both kidney and ureter to the cysteine conjugate (2-S-cysteinyl-N-isopropylacetanilide). The glutathione conjugate was not metabolized to the mercapturic acid conjugate (2-S-[N-acetyl]cysteinyl-N-isopropylacetanilide). When the mercapturic acid conjugate of propachlor was presented to the kidney, it was eliminated in urine. First-pass metabolism and elimination of the glutathione conjugate by the kidney was 16% of the dose, whereas first-pass elimination of the mercapturic acid was 33%. Absorption of the glutathione conjugate of propachlor, or its metabolites, or of glycine by the ureter was nil. The bovine species may be unable to form mercapturic acids from glutathione conjugates of some xenobiotics, which may make cattle more easily poisoned by these xenobiotics than chickens, pigs, and rats.
 ...
PMID:Propachlor-S-glutathione metabolism by kidneys and ureters of calves. 206 Dec 43

Cellular accumulation of L-cystine in rat kidney cortex in vivo has been studied using L-[(35)S]cystine. The L-[(35)S]cystine radioactivity in plasma decreases to less than 10% of the initially calculated value by 15 min. Four (35)S-containing intracellular products of L-cystine metabolism were identified including cystine, cysteine, reduced glutathione, and an as yet unidentified compound. The latter is probably taurine, cysteinesulphinate, or cysteic acid. Cellular accumulation of these products was found to be more rapid in vivo than in vitro. Cellular accumulation of the products of L-cystine metabolism was found to be essentially unchanged in the presence of ureter ligation. Unlabeled L-lysine administered simultaneously with L-[(35)S]cystine, in both the presence and absence or ureter ligation, enhanced the cellular accumulation of intracellular metabolic products of L-[(35)S]cystine. Simultaneous (35)S cellular accumulation and L-cystine clearance studies were performed both in the presence and absence of L-lysine. L-Lysine enhanced cellular accumulation of (35)S-products despite an accompanying increase in L-cystine clearance. The results are interpreted as evidence for a dissociation between cellular accumulation and transepithelial transport. This evidence for independent luminal transport and peritubular cellular accumulation could explain the apparent paradox in the disease cystinuria where there appears to be a luminal transport defect for L-cystine, but no defect for cellular accumulation of L-cystine metabolic products in vitro.
 ...
PMID:Cellular accumulation of L-cystine in rat kidney cortex in vivo. 468 83

When S-benzyl-N-acetyl-L-[U-14C]cysteine, a mercapturic acid, was administered to rats intravenously, the plasma level of radioactivity decreased very rapidly with a concomitant increase in the renal level of radioactivity. The renal radioactivity reached its maximum within 2 min and then decreased rapidly with concomitant appearance of the radioactive mercapturic acid in the urine. Bilateral ligation of the ureters resulted in only a slight decrease in the rate of disappearance of mercapturic acid from the plasma, while bilateral nephrectomy caused a marked retardation of its clearance from the plasma. Intravenous administration of probenecid, a well known inhibitor of a renal transtubular transport system for organic acids, caused a significant retardation of mercapturate clearance from the plasma in both of the control and ureter-ligated animals. The renal accumulation of this mercapturic acid as well as its excretion into urine was inhibited by probenecid. All these data suggested that a mercapturic acid in the plasma was preferentially taken up by renal tubule cells from the basolateral side of plasma membranes via the probenecid-sensitive transtubular transport system and then excreted rapidly into the lumenal space. This transtubular transport of a mercapturic acid seems to constitute an important process in the hepato-renal cooperation in the mercapturic acid biosynthesis in vivo.
 ...
PMID:Renal transtubular transport of mercapturic acid in vivo. 721 8

In three separate sets of studies, the effects of ureteral ligation and coadministration of cadmium with cysteine or glutathione (GSH) (in either a 4:1 or 2:1 ratio of thiol to cadmium) on the renal disposition of cadmium were assessed in rats 1 h after the administration of cadmium. In all experiments, co-administration of cadmium with either cysteine or GSH caused the renal accumulation of cadmium to increase significantly (by approximately 60-70%) 1 h after injection. Moreover, in all experiments in which both ureters had been ligated in a rat prior to the administration of cadmium, the net total renal accumulation of cadmium was only about 20% less than that in control animals that had not undergone bilateral ureteral ligation when cadmium was administered as cadmium chloride. Furthermore, in animals in which only one ureter had been ligated, the net accumulation of cadmium in the kidney whose ureter had been ligated was between 25 and 30% less than that in the contralateral kidney. Coadministration of cadmium with cysteine or GSH also caused the net accumulation of cadmium to be increased in rats whose ureter(s) had been ligated. Overall, the present findings indicate that there is a significant basolateral component in the acute, in vivo, renal tubular uptake of cadmium. Moreover, the findings indicate that the basolateral uptake of cadmium is enhanced when cadmium is coadministered with cysteine or GSH.
 ...
PMID:Evidence for basolateral uptake of cadmium in the kidneys of rats. 1073 40

Kidney development has often served as a model for epithelial-mesenchymal cell interaction where the branching epithelium of the ureteric bud induces the metanephrogenic mesenchyme to form epithelial nephrons. In a screen for genes differentially expressed during kidney development, we have identified a novel gene that is dynamically expressed in the branching ureter and the developing nephrons. It was designated Emu1 since it shares an N-terminal cysteine-rich domain with Emilin1/2 and Multimerin. This highly conserved EMI domain is also found in another novel protein (Emu2) of similar protein structure: an N-terminal signal peptide followed by the EMI domain, an interrupted collagen stretch, and a conserved C-terminal domain of unknown function. We identified two further secreted EMI domain proteins, prompting us to compare their gene and protein structures, the EMI domain phylogeny, as well as the embryonic expression pattern of known (Emilin1/2, Multimerin) and novel (Emu1/2, Emilin3, Multimerin2) Emu gene family members. Emu1 and Emu2 not only show a similar structural organization, but furthermore a striking complementary expression in organs developing through epithelial-mesenchymal interactions. In these tissues, Emu1 is restricted to epithelial and Emu2 to mesenchymal cells. Preliminary biochemical analysis of Emu1/2 confirmed that they are secreted glycoproteins which are attached to the extracellular matrix and capable of forming homo- and heteromers via disulfide bonding. The widespread, but individually distinct expression patterns of all Emu gene family members suggest multiple functions during mouse embryogenesis. Their multidomain protein structure may indicate that Emu proteins interact with several different extracellular matrix components and serve to connect and integrate the function of multiple partner molecules.
 ...
PMID:Developmental expression and biochemical characterization of Emu family members. 1222 Oct 2