Metabolic dependency of cadmium uptake and the relaxant effects of cadmium in smooth muscle of guinea pig tenia coli.
The effects of cadmium ions on tension and lactate release under anaerobic conditions were compared with the effects of gallopamil in tenia coli. Both 0.5 mmol X 1(-1) Cd2+ and 1 X 10(-6) mol X 1(-1) gallopamil inhibited the tensions induced by high-K+ media containing a high concentration of glucose under anoxia. The increase in lactate release from the muscle tissues induced by the addition of glucose to a high-K+ medium under anoxia was inhibited by Cd2+, whereas gallopamil demonstrated only minor effects on lactate release. Following a preincubation with 0.5 mmol/l Cd2+ for 30 min under anoxia, the tension induced by high-K+ largely returned upon washing with disodium edetate (EDTA) to levels comparable to those at preincubation under normoxia. Elimination of tissue cadmium by EDTA was greater at preincubation under anoxia than when compared to normoxia. From the demonstrated kinetics of cadmium in tenia coli, it is suggested that cadmium can enter the cell in normoxic conditions. However, when cadmium is applied under anaerobic conditions, little of it seems to be able to penetrate the cell membranes.
D000818:Animals; D002104:Cadmium / Q000378:metabolism* / Q000494:pharmacology; D003106:Colon / Q000187:drug effects; D004492:Edetic Acid / Q000494:pharmacology; D005711:Gallopamil / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D013997:Time Factors
D007773:Lactates; D002104:Cadmium; D019344:Lactic Acid; D005711:Gallopamil; D004492:Edetic Acid