A simple experimental index for the evaluation of inotropic responses.
The validity of the first derivative of systemic arterial pressure (SAdP/dt) as an indirect experimental index for the evaluation of inotropic responses was ascertained in rats anesthetized with pentobarbital sodium (40 mg/kg, i.p.), using the first derivative of left ventricular pressure (LVdP/dt) as the reference. We observed highly significant qualitative and quantitative (p less than 0.001) correlations between these two parameters, under five well-established experimental cardiovascular perturbations that are known to promote inotropic actions, viz, vagosympathetic trunk stimulation; intravenous administration of pentobarbital, epinephrine, or phenylephrine; and temporary common carotid artery occlusion. Preliminary experiments using isometric ventricular contraction as the reference also confirmed these observations. It is suggested that the SAdP/dt may qualify, at the systemic level, as an easily accessible experimental index for ventricular contractility.
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000503:physiopathology; D001794:Blood Pressure; D004558:Electric Stimulation; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains