Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Volume regulatory decrease (VRD) by Necturus gallbladder epithelial cells in Cl Ringer was unaffected by the addition of 5 mM BaCl2 to apical perfusates but was inhibited by the addition of 5 mM BaCl2 and 50 or 3 microM phencyclidine (PCP) to serosal perfusates, suggesting that K channels in the basolateral membrane were activated during VRD. VRD was unaffected by replacement of Cl with NO3 or SCN, suggesting that Cl-dependent Na-K-Cl and K-Cl cotransport were not involved. In SCN Ringer, VRD was inhibited by the addition of 0.1 mM bumetanide to serosal perfusates, suggesting that bumetanide-sensitive anion channels in the basolateral membrane were also activated. A transient 10-mV hyperpolarization of the membrane potential was associated with VRD. The channel blockers that inhibited VRD had little or no effect on the hyperpolarization, suggesting that the changes in membrane potential were unrelated to the changes in cell volume. Perfusion of the apical surface of the epithelium with isotonic solutions containing 10 mM D-glucose resulted in a variable increase in cell volume followed by a variable shrinkage to normal, suggesting that VRD was also activated during organic solute absorption. The increase in cell volume was blocked by the addition of 0.01 or 1 mM phlorizin to mucosal perfusates. The reduction in cell volume was inhibited by the addition of 0.1 mM bumetanide, but not BaCl2 or PCP, to serosal perfusates, indicating the the shrinkage mechanism secondary to glucose addition differed from that seen after exposure to hypotonic perfusates.
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PMID:Mechanisms underlying volume regulatory decrease by Necturus gallbladder epithelium. 169 94

This paper defines the culture conditions of the ciliate Spirostomum teres and assesses its sensitivity to some xenobiotics for the development of a new low-cost microbiotest. The model was selected for its ubiquitous distribution, large size for a unicellular species, easy culture in holoxenic medium, moderate generation time, and high sensitivity to pure toxicants. The influence of different culture waters, inocula of ciliates, food, temperature, light, and darkness on the growth of the ciliate population was tested. The shortest generation time (average 39 h) was obtained for cultures incubated at 25 degreesC in the dark with an inoculum of 4 ciliates per ml in 25 ml of Volvic mineral water containing 8 boiled wheat grains, when preincubated without ciliates for the previous week. Under these conditions, it was possible to obtain about 3000 ciliates/ml 3 weeks later. Acute toxicity tests (24-h LC50) were carried out for CuSO4, HgCl2, CdCl2, K2Cr2O7, ZnSO4, Pb(NO3)2, thiram, carbaryl, lindane, parathion, parathion methyl, paraoxon, 2, 4,6-trichlorophenol, and sodium pentachlorophenolate (Na-PCP). Very high sensitivity of the model to Hg2+, Cu2+, Cd2+, thiram, and Na-PCP was established. Comparison of its sensitivity with that of Microtox (current results), Daphnia Magna, Tetrahymena pyriformis, Colpidium campylum, and murine fibroblasts (data from literature) confirms the high sensitivity of the model, especially to heavy metals. Easy-to-perform, cost-effective, and sensitive bioassays using S. teres are suitable for risk assessment and early detection of toxicity in fresh water.
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PMID:A new low-cost microbiotest with the Protozoan spirostomum teres: culture conditions and assessment of sensitivity of the ciliate to 14 pure chemicals. 979 74