Some aspects of vascular pharmacology of frog (Rana tigrina).

Vascular autonomic receptors in amphibians exhibit difference from more evolved mammalian species. Vascular perfusion studies in frog indicate constrictions by prominent muscarinic but rudimentary nicotinic constrictive regulation by cholinergic systems. Difference from classical effect-patterns of pharmacological interventions, observed in the study, make room to visualise complexity of additional regulatory mechanisms.