Acetylcarbocholine and acetylsilicocholine: Directly or indirectly acting cholinergic spasmogens?

Abstract

The cholinergic and anticholinergic actions of nitrogen-free isosteres of acetylcholine and benzilylcholine are described. Esters of two kinds of choline analogues, carbocholine and silicocholine, were used. The spasmogenic activity of acetylcarbocholine and acetylsilicocholine on the guinea-pig ileum was identified as an indirect cholinergic action, in contrast to the direct cholinergic action of furtrethonium and the mainly noncholinergic action of barium ions. In addition to this indirect cholinergic action, both esters show a weak anticholinergic and a weak noncompetitive "papaverinelike" spasmolytic activity. The corresponding benzilyl esters, although without an onium group, are relatively potent anticholinergic compounds.

Comparison of inhibitory effects of lithium and magnesium on longitudinal smooth muscle contraction

“…An additional factor regarding the uptake of orally presented metals by the body i s the motility of the intestine itself.Lithium will inhibit the contractile responses of smooth muscle to many neurotransmitters and hormones (31. Similarly, high concentrations of magnesium will also reduce muscle contraction [4]. The biochemical relationship between lithium and magnesium has been discussed extensively 151.…”