Pharmacology of the retractor lentis muscle of the bluegill (Lepomis macrochirus)

Autor: H. Kunioka, H. Katayama, M. Fujimoto
Rok vydání: 1995
Předmět:
Zdroj: Journal of Comparative Physiology A. 176:673-677
ISSN: 1432-1351
0340-7594
DOI: 10.1007/bf01021587
Popis: We studied accommodative nerve-muscle transmission in a teleost fish, the bluegill (Lepomis macrochirus). The muscle contracted with electrical stimulation to move the spherical lens along the pupil plane in the eye ball so that the distance between the lens and retina changes. The dose-dependent effect on the lens muscle of acethylcholine and its related substances (nicotine, muscarine, curare and atropine), glutamate, gamma-aminobutyric acid, serotonin, glycine, dopamine and noradrenaline was observed with a binocular microscope. Its video image was processed by a computer to measure the shortening of the muscle. Among the transmitter candidates applied only acethylcholine caused a contraction and elicited the lens movement. Muscarine caused strong contraction of the muscle even in a low concentration (1 nM) while nicotine did not. The contraction was antagonized by atropine but not curare. Previous studies based on intraperitoneally injected reagents suggested a cholinergic innervation on the lens muscle. Our pharmacologic results verified by direct anatomical measurements on the isolated lens-muscle-nerve preparation unambiguously establish the dose-dependent muscarinic-cholinergic innervation to the lens muscle by parasympathetic postganglionic fibers.
Databáze: OpenAIRE