T. bahiensis VENOM INDUCES LEUKOCYTOSIS AND MYELOPOIESIS.

CARDOSO S. S.(1), TRINDADE C. B.(2), TEIXEIRA C. F. P.(3),

KWASNIEWSKI F. H.(1)

(1)Integrated Nucleus of Biotechnology; (2)Center of Interdisciplinary Investigation in Biochemistry, University of Mogi das Cruzes; (3)Laboratory of Pharmacology, Butantan Institute, São Paulo, Brazil.

In Brazil scorpions from Tityus genus are responsible by the majority of scorpion sting. There are no data about the effects of T. bahiensis venom (Tbv), but those reported for T. serrulatus include leukocytosis and cytokines in the serum. Our goal was to study the effect of Tbv on the production and mobilisation of leukocytes from bone marrow into blood. Tbv (200µg/kg) or saline (controls) were injected ip into male Swiss mice (26g) and after 0,5, 1, 3, 6 or 24h the animals were killed for performing clonogenic assays with cells from bone marrow (BMC). In brief, the cells were maintained at 37ºC and 5% of CO2 in semi-solid medium, with or without a mixture of colony stimulating factors (CSF). After 7 days the colonies (clusters with more than 50 cells) were counted with a stereoscopic microscope (40X). To investigate the effects of Tbv on blood leukocyte numbers, total and differential leukocyte counts were performed. Results showed that one hour after poisoning (n=6-12), leukocytosis (7±0,7 X 10±0,8; NaCl X Tbv, cellsX106/µL) and neutrophilia (2±0,2 X 3±0,3) were observed up to 24h (n=8-12; 6±0,7 X 18±0,8 and 2±0,2 X 7±0,5 respectively), when an increase number of lymphocytes (4±0,5 X 8±0,5), eosinophils (0,1±0,02 X 0,3±0,1) and monocytes (0,1±0,02 X 0,4±0,1) was found. The clonogenic assay with BMC obtained from 6 or 24h poisoned animals showed a synergism between Tbv and CSF (n=8-12, respectively 101±14 X 200±33 and 82±6 X 135±12). Tbv modifies the circulating leukocyte dynamics probably by mobilizing these cells from both the circulation marginal (1h after the Tbv injection) and from medullary pools (3, 6 and 24h).

KEY WORDS: scorpion venom, myelopoiesis, leukocytosis, inflammation

FINANCIAL SUPPORT: FAEP (Fundação de Amparo ao Ensino e Pesquisa)/UMC

CORRESPONDENCE TO:

Fábio Henrique Kwasniewski, Núcleo Integrado de Biotecnologia, Universidade de Mogi das Cruzes, Av. Dr. Cândido Xavier de Almeida Souza 200, Centro Cívico, CEP 08780-911 - Mogi das Cruzes, SP. Email: fhkwas@umc.br