A Humoral Mechanism Modifies Pulmonary Artery Pressure in Rabbits after Tityus discrepans Envenomation.
1Novoa, E.; 2D'Suze, G.; 1Marcano, H.; 1Friedman, E.; 1Crespo, A.; 1Tortoledo, M.; 1Sanchez de León, R. and 2Sevcik, C.
1Unit of Respiratory Physiology, UCV. Caracas and 2Laboratory on Cellular Neuropharmacology, IVIC. CBB, Caracas, Venezuela
Tityus scorpion venom is known to produce lung damage in humans and other animals. Previous studies have shown that 2 mg of Tityus venom added to 250 ml of perfusate (Krebbs-BSA saline) did not harm isolated rabbit lung preparations. In this study, we used rabbit lungs perfused with expanded rabbit blood. Six isolated rabbit lungs were used as controls. The perfusate of the other preparations (6 preparations per group, 4 experimental groups) was mixed with 10 ml of serum (SV) from other rabbits obtained 0.5, 2, 4, or 6 hours after 2 mg SQ injection of venom. Pulmonary artery pressure (Pap), airway pressure, left atrium pressure, and fluid filtration rate were always recorded. Only Pap changed, increasing transiently but significantly, in all experimental groups after SV addition to the perfusate (P<0.05). The maximum change in Pap occurred 2 min after adding SV, and the increase lasted < 30 min prior to returning to basal values. We did not observe significant differences between the 4 experimental groups. These results show that scorpion venom produces changes in Pap through an indirect humoral mechanism, which is completely active 30 min after SQ venom injection. The effect of SV was similar to that produced by 0.5 mg/l platelet aggregating factor (PAF) in isolated rabbit lungs. Financed in part by CONICIT (Venezuela) grants No. S1-970000034 and S1-95000722.
Publication Dates
-
Publication in this collection
08 Oct 2002 -
Date of issue
Dec 2001
