ULTRASTRUCTURAL AND HISTOCHEMICAL-STUDY OF COLLAGEN-FIBERS TYPE-I ANDTYPE-III IN THE VENOM GLAND OF BOTHROPS-JARARACA DURING SECRETORY CYCLE

Fragments of snake (Bothrops jararaca) venom gland were analysed by li ght and transmission electron microscopy in order to characterize the changes in collagen fibres types I and III in the intertubular gland s epta during the secretory cycle. The snakes were sacrificed at 45 clay s (unmilked group), 6 h, 4 and 8 days after manual extraction of the v enom. The fragments were fixed, processed according to standard histol ogic technique for embedding in paraffin, and stained with haematoxyli n-eosin and Gomori's trichrome and submitted to Gomori's silver impreg nation technique and picrosirius-polarization method. For transmission electron microscopy the fragments were fixed and processed for embedd ing in Spurr's medium. At the 45th day (the gland at rest), when the s ecretory activity was at a minimum, the septa were narrow and filled w ith densely packed collagen fibrils, At 6 h, the septa were enlarged a nd exhibited wide spaces filled with finely granular Alcian Blue-posit ive material. Until the 8th day, the septa were narrower and the histo logic aspect resembled that of the gland at rest. The results demonstr ated structural modifications in the glandular septa according to the different periods of the secretory cycle. These modifications can he a ssociated with the transformation in the secretory epithelium during t he venom synthesis cycle.