ACTIONS OF GYROXIN, ISOLATED FROM Crotalus durissus cascavella VENOM, IN THE ISOLATED RAT KIDNEY

MARTINS, A.M.C., TOYAMA, M.H., OLIVEIRA, D.G., MARANGONI S., ALMEIDA, A.C.P., HAVT, A., NOBRE, A.C.L., BARBOSA, P.S.F., FACÓ, P.E.G., FONTELES, M.C., MONTEIRO, H.S.A.

Unicamp and Federal University of Ceará, UFC. 

Objectives: Envenomation by Crotalus genus leads to coagulation disorders, myotoxicity, neurotoxicity and acute renal failure, which is the principal cause of death. Thus we investigate the actions of the gyroxin isolated from Crotalus durissus cascavella on renal function.

Methods and Results: The isolated rat kidneys were perfused with Krebs-Henseleit solution containing 6% of bovine serum albumin in absence and in presence of toxins. The parameters studied included perfusion pressure (PP), renal vascular resistance (RVR), glomerular filtration rate (GFR), urinary flow (UF), percent of sodium tubular transport (%TNa⁺), percent of potassium tubular transport (%TK⁺) and percent of chloride tubular transport (%TCl^-). Maximum effects were seen in the last 30 minutes of each perfusion named 120 minutes. Treated group (gyr) was compared to a control group (ct) analyzed by Student t Test (*p<0,05). Gyroxin (5 mg/ml) increased significantly the PP (ct₁₂₀ = 114.3 ± 3.2 mmHg, gyr₁₂₀ = 144.5 ± 4.5 mmHg*) and RVR (ct₁₂₀ = 5.3 ± 0.05 mmHg/mL.g^-1.min^-1, gyr₁₂₀ = 7.0 ± 0.5 mmHg/mL.g^-1.min^-1*) and UF in the last 30 minutes of each perfusion, but GFR (ct₁₂₀ = 0.65 ± 0.01mL.g^-1.min^-1, gyr₁₂₀ = 0.67 ± 0.04 mL.g^-1.min^-1) remained stable during the 120 min. of perfusion. The %TNa⁺ (ct₁₂₀ = 81.2 ± 0.3, gyr₁₂₀ = 69.9 ± 1.9*) %TK⁺(ct₁₂₀ = 69.9 ± 0.9, gyr₁₂₀ = 63.7 ± 0.9*) and %TCl^- (ct₁₂₀ = 78.9 ± 0.9, gyr₁₂₀ = 72.0 ± 1.1*) decreased significantly after the infusion of gyroxin.

Conclusion: These results indicate that gyroxin participates in the toxic effect of Crotalus durissus cascavella venom on isolated rat kidney.

Supported by: FAPESP, CNPq

CORRESPONDENCE TO:

Alice Maria Costa Martins, Rua Antônio Augusto Apto. 101, Fortaleza, CE, CEP: 60000-000, Email: martinsalice@hotmail.com