Differences in venom toxicity and antigenicity between females and males Tityus nororientalis (Buthidae) scorpions

Research Article

J Venom Res (2010), Vol 1, 61-70

Published online: 21 October 2010

Full Text: (PDF ~1243kb) | (PubMed Central Record HTML)

Leonardo De Sousa †‡*, Adolfo Borges ‡§, Aleikar Vásquez-Suárez †‡, Huub JM Op den Camp δ, Rosa I Chadee-Burgos †‡, Mirna Romero-Bellorín βλ, Jorge Espinoza §, Leonardo De Sousa-Insana ‡ψ, Oscar Pino-García ‡ψ

† Laboratorio de Toxinología, Sección de Farmacología, Departamento de Ciencias Fisiológicas, Escuela de Ciencias de la
Salud, Universidad de Oriente, Núcleo de Anzoátegui, PO Box 4774, Puerto La Cruz 6023, Anzoátegui, Venezuela

‡ Grupo de Investigación en Toxinología Aplicaday Animales Venenosos, Escuela de Ciencias de la Salud, Universidad de Oriente,
Núcleo de Anzoátegui, Puerto La Cruz, Venezuela

§ Laboratorio de Biología Molecular de Toxinas y Receptores, Sección de Biomembranas, Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Caracas,
Venezuela

δ Department of Microbiology, Radboud University Nijmegen, Nijmegen, The Netherlands

λ Postgrado de Biologia Aplicada, Escuela de Ciencias, Universidad de Oriente, Núcleo de Sucre, Cumaná, Venezuela

ψ Unidad Educativa Juan Jacobo Rousseau, Puerto La Cruz, Venezuela


*Correspondence to: Leonardo De Sousa, Email: leonardodesousa@yahoo.com, Tel: +58 416 6811756, Fax: +58 281 4203219


Received: 31 August 2010, Revised: 12 October 2010, Accepted: 14 October 2010


© Copyright The Authors


ABSTRACT

Venom from male and female specimens of the medically important Venezuelan scorpion Tityus nororientalis have been compared. Males showed a signifi cantly higher venom yield (2.39mg/individual) compared to female scorpions (0.98mg/individual). Female venom was significantly more toxic than that of males, with a median lethal dose (LD50) in C57BL/6 mice of 9.46 μg venom protein/gm body weight [95% confidence interval (8.91-9.94)] whereas LD50 for males was 13.36(12.58-14.03) μg/gm. Mass spectral analyses by MALDI-TOF revealed differences in venom composition between males and females. From a clinical standpoint, the time course of toxicity course indicated a tendency, in the case of the female venom, to elicit the earlier occurrence of severe signs such as sialorrhea, dyspnea (bradypnea/apnea) and exophthalmus particularly in the late toxicity phase. Female venom was signifi cantly less effi cient than male venom to inhibit the binding of anti-T. discrepans antibodies to immobilized T. discrepans venom in ELISA assays, suggesting sex-related differences in the bioactive surfaces of T. nororientalis toxins. These results indicate that males and females of T. nororientalis produce venoms with different composition and activity which may have epidemiological implications.

KEYWORDS: Intersexual variation ; scorpion ; Tityus nororientalis ; Venezuela