Mechanism of dichlorovos-induced inhibition of calcium-dependent contractions in the rat tail artery.
The inhibitory effect of dichlorovos (an organophosphate pesticide) on Ca(2+)-dependent contractions has been studied in isolated helical strips of rat tail arteries. Isometric contractions were evaluated under standard organ bath conditions. Dichlorovos caused concentration-dependent relaxation of 10(-7) M NE-induced contractions as well as inhibition of both phasic and tonic components of NE contractions. Extracellular calcium-dependent contractions in K(+)-depolarized medium as well as NE-induced contractions due to mobilization of membrane-bound calcium pool and intracellular calcium-dependent caffeine contractions were significantly attenuated by dichlorovos. The results strongly support our previous observation that dichlorovos interferes with calcium metabolism in the rat tail artery.
Ebeigbe
A B
AB
Department of Physiology, University of Benin, Nigeria.
Campbell
P I
PI
Aloamaka
C P
CP
D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004006:Dichlorvos / Q000494:pharmacology*; D066298:In Vitro Techniques; D008566:Membranes / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013623:Tail / Q000098:blood supply; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D004006:Dichlorvos; D002118:Calcium; D009638:Norepinephrine