Hemicholinium-3 and related ether analogues on the synthesis of acetylcholine by mouse brain (in vitro).

Incubation of minces prepared from whole brains of mice in high (25 mM) potassium (HK) medium resulted in the synthesis and release of more than 4-times the acetylcholine (ACh) formed and released from non-depolarized minces incubated in low (4 mM) potassium (LK) medium; however, potassium (K)-depolarized minces. The calcium (Ca)-dependent release of ACh evoked by K-induced depolarization appears to consist primarily of newly-formed transmitter, since this release was inhibited within 1 min after the addition of 0.1 microM hemicholinium-3 (HC-3) and was promptly reversed by choline.

Pharmacological activities of acetal derivatives of hemicholinium no. 3.

Acetal derivatives of hemicholinium no. 3 (HC-3) were synthesized and their chemical structures were confirmed by spectrophotometric evidence and elemental analysis. The acetals elicited a biphasic pattern of neuromuscular inhibition in the cat: (a) an immediate inhibition (early phase block) was judged to be curare-like as responses to acetylcholine (close i.

Synthesis and structure-toxicity relationships of three new stable analogues of acetyl-seco-hemicholinium-3.

In order to develop and study inhibitors of neuromuscular function which act presynaptically, three stable analogues of acetyl-seco-hemicholinum-3 (AcHC-3,2) were prepared. These analogues have 2-ethoxyethyltrimethylammonium, 4-oxopentyltrimethylammonium, and n-pentyltrimethylammonium moieties substituted for the 2-acetylethyltrimethylammonium (acetylcholine) moieties of AcHC-3 (2) to form the ether 2, ketone 4, and alkane 5 analoggues of AcHC-3 (2). Although AcHC-3 (2) has been shown to undergo deesterification rapidly in basic solutions and slowly at pH 7.