Simultaneous continuous monitoring of blood volume and permeability in rabbit synovium: action of histamine

Abstract

We have recently reported that daily intraperitoneal (i.p.) injections of Cimetidine hydrochloride (1 mg/kg) greatly suppressed the joint swelling occurring in the early and late phases of rat adjuvant arthritis¹. This apparent anti-inflammatory effect of Cimetidine was not due to non-specific actions. Injection of the same dose of Cimetidine hydrochloride (i.p.) suppressed the swelling produced by injection into the paw pad of the specific H₂ agonist, Dimaprit, but not that due to the H₁ agonist, 2-pyridylethylamine. To learn more about the roles of histamine H₁ and H₂ receptors in the synovial micro-vasculature, we have devised a technique to simultaneously monitor blood volume and permeability in the rabbit synovium.