Oct 15, 1992

Positive and negative inotropic effects of carbachol on the embryonic chick atrium

L L Protas


The effect of carbachol on twitch tension of atrial preparations from chick embryos of different incubation ages (3-14 days) was studied. At every age carbachol evoked negative (at low concentrations) and positive (at higher concentrations) inotropic responses. Maximal response values for both effects increased with age; in 3- and 5-day atria the positive inotropic response prevailed. The muscarinic antagonist pirenzepine inhibited the positive (on 5-day atria) and negative (on strips of 14-day atria) inotropic effects of carbachol with pA2 values of 6.8 and 8.0, respectively, suggesting that muscarinic receptors mediating these effects belong to different receptor subtypes.

Mentioned in this Paper

Myocardial Contraction
Cholinergic Muscarinic Antagonist [EPC]
Right Atrial Structure
Chick Embryo
Entire Atrium
Heart Atrium
Muscle Twitch

Related Feeds

Cardiac Electrophysiology

Cardiac electrophysiology is the study of electrical activities of the heart and includes the assessment, diagnosis, and treatment of cardiac events. Find the latest research on cardiac electrophysiology here.