Dominant anti-vagal effect of pentobarbital on cardiac responses to intracardiac autonomic nerve stimulation in the dog.
The isolated canine atrium was perfused by heparinized blood of the donor dog. An adequate dose of pentobarbital that induced a potent hypotension in the donor did not produce any significant change in the atrial rate and developed tension in the isolated atrium perfused with donor's blood. Pentobarbital in doses that modified neither cardiac responses to intracardiac adrenergic nerve stimulation nor exogenously given norepinephrine or acetylcholine significantly inhibited intracardiac vagal responses. From these results, it is concluded that a large dose of pentobarbital has a dominant antivagal effect in the heart.
Chiba
S
S
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan. Chiba@sch.md.shinshu-u.ac.jp
Tsuboi
M
M
D000818:Animals; D017776:Autonomic Pathways / Q000187:drug effects* / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004285:Dogs; D004558:Electric Stimulation; D006325:Heart Atria / Q000187:drug effects / Q000294:innervation; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D009924:Organ Culture Techniques; D010424:Pentobarbital / Q000008:administration & dosage / Q000494:pharmacology*; D014630:Vagus Nerve / Q000187:drug effects* / Q000502:physiology
D006993:Hypnotics and Sedatives; D010424:Pentobarbital