THE INFLUENCE OF PB2-RECEPTOR( ON EXPRESSION OF ACETYLCHOLINESTERASE AND THE ACETYLCHOLINE)

This paper examines the influence of inorganic lead (Pb2+) on the pres ence of acetylcholinesterase (AchE) molecular forms and the acetylchol ine receptor (AchR) in two types of excitable tissue, primary cultures of skeletal muscle and neural retina from embryonic chick. Treatment of skeletal muscle with Pb2+ is observed to cause reductions in the 5/ 7S and 19S but not the 11.4S molecular forms of AchE. The reductions a re dose-dependent, requiring submicromolar concentrations, slow in ons et, requiring incubation times greater than 24 hr, and tissue specific , being pronounced in skeletal muscle but absent from neural retina. S ignificantly, the reductions in AchE occur without corresponding reduc tions in amounts of AchR and without reduction in activity of protein kinase C (PKC), These studies illustrate a tissue-specific action of i norganic lead that is not mediated through PKC. (C) 1997 Academic Pres s.