Hepatic sinusoidal responses to intraportal injections of phenylephrine and isoprenaline in the rat.
1. Specific alpha- and beta-adrenoreceptor agonists, phenylephrine and isoprenaline, were injected intraportally into the intact rat liver under direct microscopic observation by an in vivo transillumination technique. 2. The diameter of a hepatic sinusoid and the intra-sinusoidal erythrocyte velocity were quantitatively measured, and the sinusoidal volume flow was calculated from these two parameters. 3. Results show that phenylephrine causes a sinusoidal constriction and an increased sinusoidal blood flow, whereas isoprenaline causes the opposite effects on the sinusoids. 4. All the sinusoidal responses to phenylephrine and isoprenaline were dose-dependent and were possibly related to the direct effect of these drugs on the sinusoids.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D007275:Injections, Intravenous; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects*; D008102:Liver Circulation / Q000187:drug effects; D008297:Male; D010656:Phenylephrine / Q000008:administration & dosage / Q000494:pharmacology*; D011169:Portal Vein; D051381:Rats
D010656:Phenylephrine; D007545:Isoproterenol