Time course of the spasmolytic effect of cadmium and cadmium uptake in guinea-pig taenia coli.
The relationship between tension inhibitory action of cadmium and cadmium uptake was investigated in the smooth muscle of taenia coli. Following a treatment with 0.5 mM Cd2+ for short periods (1, 5 min), the tension to high-K+ returned to a greater extent after washing with disodium edetate (EDTA) or cysteine, compared to normal medium. However, the restored tension to the high-K+ decreased with increasing duration of Cd2+ treatment. With a longer duration of 0.5 mM Cd2+ treatment, the cadmium uptake increased and the size of cadmium fraction bound to cells firmly increased. It is suggested that Cd2+ binds initially to the surface membrane of taenia coli and that Cd2+ subsequently migrates to a compartment that EDTA cannot reach.
D000818:Animals; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology*; D003106:Colon / Q000502:physiology; D003545:Cysteine / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000378:metabolism / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology
D002104:Cadmium; D004492:Edetic Acid; D003545:Cysteine; D011188:Potassium