EFFECTS OF THE TITYUSTOXIN ISOLATED FROM Tityus serrulatus SCORPION VENOM IN PERFUSED RAT KIDNEY

ALVES R.S. (1), MARTINS R.D. (1), SOUSA D.F. (1), ALVES C.D. (1), APRÍGIO C.C. (1), QUEIROZ M.G.R. (3), MARTINS A.M.C. (3), TOYAMA M.H. (4), FONTELES, M.C. (1), MONTEIRO, H.S.A. (1)

(1)Department of Physiology and Pharmacology, (2)Department of Pathology and Legal Medicine and (3)Department of Clinical and Toxicology Analysis/ Federal University of Ceará, (4)Department of Chemistry, Sao Paulo State University.

Tityus serrulatus is the most dangerous scorpion species accounting for fatal stings, especially among children, in Brazil. The tityustoxin is a rich source of various polypeptides with diverse physiological and pharmacological activities that generally exert their action via target specific modulation of ion channel function. The aim of present work was to determine the effects of tityustoxin isolated from Tityus serrulatus (TsTx) venom in isolated perfused kidney from Wistar rats, as it was described by Fonteles et al., 1983 (1). The effects of 3µg/mL toxin concentration (n=6) were studied on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), sodium (%TNa+), potassium (%TK+) and chloride (%TCl-) tubular transport. All experiments were preceded by 30 minutes of internal control (C). The data were analyzed by ANOVA and Student t-test with level of significance was set at *p<0.05. The TsTx increased the PP (C = 109.7 ± 0.75 vs. TsTx = 112.15 ± 0.17 mmHg*) and RVR (C = 5.95 ± 0.04 vs. TsTx = 6.13 ± 0.01mmHg.min-1.g-1.min*) at 60 min. The toxin also increased UF with maxim effect at 120 min (C = 0.10 ± 0.01 vs. TsTx = 0.13 ± 0.004 mL.g-1.min-1*). The toxin reduced %TNa+ (C = 71.92 ± 1.45 vs. TsTx = 62.3 ± 2.43%*) and %TCl- (C = 69.13 ± 1.68 vs. TsTx = 59.22 ± 2.35%*) at 90 min. In conclusion, TsTx altered the renal functional parameters evaluated and it is mainly responsible for the increase of urinary flow induced by crude venom.

KEY WORDS: scorpion, Tityus serrulatus, tityustoxin, renal effects.

REFERENCE: (1) FONTELES, M. C. et al. (1983). Am J Physiology 44: 191-197.

FINANCIAL SUPPORT: CNPq.

CORRESPONDENCE TO: MONTEIRO, Helena S. A. Department of Physiology and Pharmacology/ Federal University of Ceará. Phone: +55 85 33668247. Fax: +55 85 33668333. Email: renatasalves@gmail.com