Modulation of the number of muscarinic receptors in mouse neuroblastoma cells by soman.

Long-term preincubation at 37 degrees of mouse neuroblastoma cells (clones NS-20 and N1E-115) with soman, a potent and irreversible cholinesterase inhibitor, resulted in a significant decrease in the number of [3H]N-methylscopolamine binding sites and in the inhibition of carbamylcholine-induced cyclic GMP formation. The disappearance of surface muscarinic receptors and the desensitization of the receptor-mediated response seem to occur via accumulation of acetylcholine in the culture medium. The significance of these findings is discussed.

[Electrophoretic study of aged butyrylcholinesterase after inhibition by soman].

The following states of purified tetrameric form (C4) of human plasma butyrylcholinesterase were studied by electrophoretic techniques: native, inhibited by soman and by methane sulfonyl fluoride and soman-aged. In order to detect a significant conformational change of the aged cholinesterase as compared to the non-inhibited (native) species, enzymes were treated with a set of bifunctional reagents (diimidates) of different chain lengths. After denaturation, the cross-link products were subjected to sodium dodecyl-sulfate polyacrylamide gel electrophoresis.

Histological and histochemical changes in the central nervous system of the rat poisoned by an irreversible anticholinesterase organophosphorus compound.

The effect of soman, a powerful organophosphorus (OP) cholinesterase inhibitor, was investigated in the central nervous system (CNS) of Wistar rats by neurohistology, histochemical mapping of acetylcholinesterase (AChE), and biochemical determination of cholinesterase (ChE) activity. Rats were poisoned by one lethal or sublethal subcutaneous (s.c.

[Activity of gamma-glutamyl transferase of sheep cerebral cortex with respect to amino acids and glutathione].

gamma-glutamyl Transferase fron Sheep brain cortex capillaries was studied from the point of view of transport of aminoacids across blood brain barrier. Excess substrate inhibition was competitive and observed both with donor (glutathione) and various acceptors (methionine, alanine, tryptophan) but not with arginine. Excess glutathione inhibition of transfer reaction is concomitant with an increase of total reaction (transfer + hydrolysis + autotranspeptidation).