The mean circulatory pressure, reproducibility of its measurements and the effect of phenylephrine with a note on the effect of pentobarbital.
With 7 repeated measurements of the mean circulatory pressure (MCP) over a course of 35 minutes in one and the same dog, and also with paired measurements of MCP 10 minutes apart in 6 other dogs, the MCP was shown to be stable and reproducible in anesthetized, open-chest and vagus-intact dogs. Administered to 7 dogs with initial mean arterial blood pressure as low as 64 mmHg in dose of 20 mug/kg intravenously, phenylephrine nearly doubled the mean arterial blood pressure, total peripheral resistance and the MCP, indicating a marked vasoconstrictor effect on the resistance and capacitance blood vessels of the systemic circulation. The effect was transient and there were signs of tachyphylaxis. Influence of a cardiotoxic dose of pentobarbital on the peripheal circulation was discussed.
D000818:Animals; D001011:Aorta / Q000502:physiology; D016275:Atrial Function; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D008365:Manometry; D010424:Pentobarbital / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects
D010656:Phenylephrine; D010424:Pentobarbital