ANALYSIS OF LUNG COMPLIANCE AFTERTityus serrulatus ENVENOMATION IN ANESTHETIZED MICE UNDER MECHANICAL VENTILATION

PERES A. C. P. (1), NONAKA P. N. (1), FERRARI E. F. (1), CARREIRO DA COSTA R. S. (1), SILVA C. A. M. (2), AMORIM C. F. (1), TOYAMA M. H. (3), RIBEIRO W. R. (1), COGO J. C. (1), OLIVEIRA L. V. F. (1)

(1) Vale do Paraíba University - UNIVAP,  IP&D,  São José dos Campos-SP,  Brazil;  (2) Department of Respiratory Physiology,  Brasília University - UNB, Brasília - DF, Brazil; (3) State University of São Paulo-UNESP, São Vicente-SP.

The severity of scorpion envenomation is related to the cardiorespiratory alterations it may provoke, with manifestations such as pulmonary edema and circulatory failure triggering death. This study aimed to test if this venom could induce lung compliance alterations after 3 h venom injection. Eighteen Swiss mice, were analysed twelve hours after intraperitoneal injection of saline (control group) or T. serrulatus crude venom (0,6 mg.g-1) The sub-lethal dose used in venom group, was determined by the LD50 previously found. The mechanical parameters were obtained by End Inspiratory Oclusion Method. The statistical analysis was carried through the Kolmogorov-Smirnov test for normality and the independent t-test in a significance level of 5%. Static elastance, dynamic elastance, P1 and P2 increased (p<0,05), after 3 hours venom injection. These finds are in part due to the fact that scorpion toxin induces pulmonary edema in humans and experimental animals, fact that could explain the increased viscous properties. Variations in the elastic and viscoelastic properties could be correlated with the severity of the pulmonary inflammation. According to the literature, histological examination of the lungs showed a slight or moderate edema characterized by intra-alveolar plasma leakage, alveolar wall thickening, areas of collapse and mononuclear inflammatory infiltration which can account for the reduction in lung elasticity and, therefore, lung compliance.

KEY WORDS: scorpion, venom, Tityus serrulatus, lung compliance, mechanical ventilation.

FINANCIAL SUPPORT: FAPESP, CAPES, UNIVAP.

CORRESPONDENCE TO: LUIS VICENTE FRANCO DE OLIVEIRA, IP&D – UNIVAP, São José dos Campos-SP, Brazil. Phone/Fax: + 55 12 39471144. Email: oliveira@univap.com