PHARMACOLOGY OF INSECT VISCERAL MUSCLE

1. 1. At least five sites-of-action must be considered in most visceral nerve-muscle preparations. 2. 2. L-Glutamate is perhaps the excitatory neuromuscular transmitter in some organs of the viscera but not others. Proctolin is probably a neuromuscular transmitter in some organs of the viscera defined criteria for rapid chemical transmission. 3. 3. Although 5-HT and certain catecholamines are present in insects and have a pronounced effect on visceral muscle no functional roles has been established for them. 4. 4. Various peptides released from neuroendocrine organs probably regulate visceral muscle function. Moreover such hormonal actions seem to be mediated by cyclic AMP in some cases. 5. 5. Recent developments in methods for detecting peptides and prospective transmitters have increased the possibility of rapid progress in insect nerve-muscle pharmacology. © 1979.