Systemic pathological alterations caused by Philodryas patagoniensis colubrid snake venom in rats

Abstract

Very little is known about the systemic effects caused by Philodryas patagoniensis colubrid snake venom. In this work, this venom was tested for its ability to induce histopathological changes in rats after its intramuscular, subcutaneous, or intravenous administration, by light microscopic examination of some organs (cerebellum, cerebrum, lung, liver, kidney, and heart). Four rats were used for each dose of 0.23, 0.45, and 0.90 mg of venom in 0.3 ml of phosphate-buffered saline solution (pH 7.4). Aliquots of blood were withdrawn at different time intervals for enzymatic determination of alanine aminotransferase, aspartate aminotransferase, and creatine kinase levels. After 2 h the animals were killed by an overdose of anesthetic, and samples of kidney, heart, liver, lung, cerebrum, and cerebellum were taken for microscopic examination (hematoxylin and eosin stain). Histologically, no abnormality was observed in heart tissue in any of the administration routes of the venom used. However, histological observations showed multifocal hemorrhage in cerebellum, cerebrum, and lung sections; severe peritubular capillary congestion in kidney sections; and hydropic degeneration in liver sections when venom was administered intravenously. The subcutaneous route showed similar results to the previous one, with the exception of cerebellar hemorrhage. Intramuscularly, neither cerebral nor cerebellar hemorrhage was observed. Plasma alanine aminotransferase and aspartate aminotransferase increased levels were demonstrated, mainly when venom was administered intravenously or subcutaneously. Our results suggest that P. patagoniensis venom induces moderate histopathological changes in vital organs of rats. These changes are initiated at early stages of the envenomation and may be associated with a behavioral or functional abnormality of those organs during envenoming.