Caracterização histológica da glândula de Duvernoy da serpente Philodryas nattereri Steindachner, 1870

Abstract

Philodryas nattereriis a snake known popularly as field-runner or board, founded in regions of caatinga and in the Brazilian semiarid region. These snakes have a well-developed Duvernoy gland, connected to a grooved tooth, specialized for toxin inoculation. The work aimed to perform the histological characterization of the Duvernoy gland of the P. nattererisnake. For the study, four pairs of animal glands from research projects in natural history and distribution of herpetofauna were used, which were registered and deposited in the NUROF Herpetological Collection. After dissection, the glands underwent histologicalprocessing, where they were fixed in 10% buffered formaldehyde, dehydrated in increasing concentrations of alcohol and later diaphanized in xylol. After inclusion in paraffin, the blocks were microtomized, with 5 μm cuts to make the slides. Hematoxylin-eosin and toluidine blue were used for staining. For the histochemical study, Schiff's periodic acid (PAS) and PAS + salivary amylase were used. Macroscopically, the Duvernoy gland had an ovulated, lobulated and elongated shape, with a whitish color. The average length was 6 mm for the left gland and 7 mm for the right. Regarding height measurement, the left and right glands had an average of 3 mm each. Photomicrographs revealed that the Duvernoy gland is lined by a dense connective tissue capsule, divided into lobes by septic connective tissue. Each lobe contains secretory tubules formed by serous cells, which indicates production of proteins as enzymes. Glands with mucous cells were observed in the excretory duct, which may be related to the production of glycoproteins. We conclude that the Duvernoy gland of the snake P.nattererifalls into the second histological category according to Taub (1967), which consists of a predominantly serous gland, with intercalated mucous cells