Modification of receptors for acetylcholine in the early embryonic heart

✍ Scribed by Roberts, Carmel Montgomery ;Gimeno, Martha A. ;Leyden Webb, J.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1965
• Tongue: English
• Weight: 481 KB
• Volume: 66
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030660304

✦ Synopsis

Whole chick embryo blastoderms at zero-to 7-somites have been explanted onto a nutrient medium and incubated at 37°C for 20 hours, in order to develop to 18to 19-somites, when the heart rate is depressed by acetylcholine and even more strongly by a number of parasympathomimetic drugs and cholinesterase inhibitors. Hence we have concluded that receptors for acetylcholine are present in the early chick embryo heart before innervation by the vagus nerve is initiated, but that the receptors do not possess the specificity of adult acetylcholine cardiac receptors. Incubation of the zero-to 7-somite blastoderms on media containing certain of the parasympathomimetic drugs and cholinesterase inhibitors greatly increased the sensitivity of the hearts to depression of rate by acetylcholine at 18-to 19-somites, and we have concluded that development of acetylcholine receptors has been stimulated by the drugs. A possible stereochemical relationship between acetylcholine receptors and drugs that are able to stimulate the development of the receptors is postulated.