Histological analysis of the damage to toad bladders caused by a myotoxic Lysine-49 phospholipase A2 from Agkistrodon contortrix laticinctus snake venom
Braz. j. morphol. sci
;
24(1): 55-58, jan.-mar. 2007. ilus
Article
in English
| LILACS
| ID: lil-497607
ABSTRACT
Agkistrodon contortrix laticinctus myotoxin (ACLMT) is a myotoxic Lys49 phospholipase A2 isolated from the venom of the broad-banded copperhead, A. c. laticinctus. We have previously shown that ACLMT affects water transport in toad bladders, but little in known about the mechanisms involved in the action of this toxin on membrane permeability. In this study, we examined the morphological alterations caused by ACLMT in toad bladder epithelium. The bladders were exposed to the toxin (20 nM) for 30 min at 23o C using Bentleys technique. Longitudinal and cross sections were obtained from paraffin-embedded bladders and stained with hematoxylin-eosin prior to analysis by light microscopy. Exposure to the toxin resulted in disorganization of the epithelial cell layer and damage to the smooth muscle bundles. The smooth muscle cells were swollen, with hypercontracted myofi laments and clear areas among the fibers. These findings suggest that ACLMT affects the structural integrity of the epithelium, and that the pathological changes induced by this toxin in smooth muscle cells may be caused by an increase in the cytosolic calcium concentration. These results contribute to our understanding of the mechanisms involved in the action of snake venom Lys49 PLA2 myotoxins in biological tissues.
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Index:
LILACS (Americas)
Main subject:
Phospholipases A
/
Urinary Bladder
/
Agkistrodon
/
Crotalid Venoms
/
Myocytes, Smooth Muscle
/
Epithelial Cells
Limits:
Animals
Language:
English
Journal:
Braz. j. morphol. sci
Journal subject:
Anatomy
Year:
2007
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Federal University of São Carlos/BR
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