title: Innervation of bat heart: cholinergic and adrenergic nerves innervate all chambers.
abstract: Adult Miniopterus schreibersii were anesthetized with chloroform, and in vitro preparations of cardiac chambers were prepared. Stimulation of intramural nerves in right ventricles paced at 6 Hz caused an inhibition (56.3 +/- 3.5% decrease on basal force) mediated by cholinergic nerves and an excitation (91.5 +/- 9.9% increase on basal force) mediated by adrenergic nerves. Mean pD2s (-log effective concentration, 50%) for ventricular beta-adrenoceptors and muscarinic cholinoceptors were 6.99 +/- 0.03 and 6.42 +/- 0.07, respectively. The inhibition of ventricular contractility, by nerve stimulation or exogenous acetylcholine, occurred even after blockade of beta-adrenoceptors. The results were comparable to those obtained on atria. In some experiments, the heart was perfused in situ and paced via electrodes on the ventricle: stimulation of the right vagus nerve decreased right ventricular contractility by up to 90%. The results show that, at least in this hibernating mammal, there is an adrenergic innervation of the ventricle. The presence of a cholinergic vagal innervation capable of inhibiting the basal force of ventricular contraction has not been shown in any other mammal.
mesh_terms: D000818:Animals; D002302:Cardiac Output; D002304:Cardiac Pacing, Artificial; D002685:Chiroptera / Q000033:anatomy & histology*; D004734:Energy Metabolism; D005260:Female; D006321:Heart / Q000294:innervation* / Q000502:physiology; D006605:Hibernation; D008297:Male; D051379:Mice; D009200:Myocardial Contraction; D010275:Parasympathetic Nervous System / Q000033:anatomy & histology*; D013564:Sympathetic Nervous System / Q000033:anatomy & histology*; D014630:Vagus Nerve / Q000033:anatomy & histology / Q000502:physiology