Pharmacological Studies of the Hemorrhagic Principles Isolated from the Venom of Trimeresurus flavoviridis, a Crotalid

Abstract

Hemorrhage is one of the most prominent local symptoms evoked by crotalid and viperid venoms (Boquet, 1964; Ohsakaet al., 1966; Jiménez-Porras, 1968). Recently, Ohsaka et al succeeded in isolating two immunologically distinct hemorrhagic principles, HRl and HR2, from the venom ofTrimeresurus flavoviridis, a crotalid (Omori-Satoh and Ohsaka, 1970; Takahashi and Ohsaka, 1970a; Ohsaka et al., 1971a). Cinematographic observations on a microscopic level demonstrated that the early effects of crude venom or venom hemorrhagic principles on the microcirculatory system are characterized by severe vasoconstriction followed by vasodilatation of larger vessels, especially of arterioles, and subsequent hemorrhage in the capillary bed (Ohsaka et al., 1971b); the erythrocytes come out one by one through the pinpoint holes formed through the walls of true capillaries (Ohsaka et al., 1971b; Tsuchiya et al., 1974). Electron- microscopic examination of the vascular endothelial cells treated with the venom or venom hemorrhagic principle (HRl) revealed that the erythrocytes come out through the junctions of the endothelial cell lining, the adjacent basement membrane being disrupted to permit eventual extravasation of the erythrocytes (Tsuchiya et al., 1974; Ohsaka et al., 1975).