Expressão imuno-histoquímica da calponina em glândula parótida de rato após obstrução do ducto excretor principal

Abstract

Glandular atrophy is one of several alterations which can aflict the salivary glands, caused generally by obstructive lesions such as sialo1ithiasis, infections or compression by neoplastic processes arnong others. In this work, a morphological and immunohistochemical study was carried out in rat parotid glands, which were submitted to obstruction of the main excretory duct suffering atrophy at varied time intervals, with the aim of appraising the behavior of myoepithelial cells during the process of glandular atrophy. It was analized the immunohistochemical expression of calponin which detects myoepithelial cells in the parotids of 28 animaIs, which were divided into 7 groups, each one made up of 4 rats, afier the ductal ligature procedure, in the following time intervals: zero hour (control), 24 hours, 7, 15, 21, 30 and 60 days. Analysis of the immunohistochemicaI profile was carried through in which the calponin expression was veritied through its distribution pattem and numericaI index. All specimens exhibited positivity for calponin in myoepithelial cells which were distributed around the acini and the ductaI structures, a small number of positiveIy marked cells being detected in the controI group and in the 24-hour group when compared to subsequent ones, where it was perceived a Iarge increase in the number of positiveIy marked cens, mainly surrounding the ductiform structures which originated during the obstruction time. Upon application of statistical tests it was verified that the rise in the number the myoepithelial positive cells for calponin, when the control groups (zero hour) was compared to the 7, 15,21, 30 and 60-day groups afier obstruction, was statistica1ly significant. It was concluded then that the detected rise probably carne about due to an elevation in the rate of proliferation of the myoepitheliaI cells subsequent to the ductal obstruction, associated with a growing resistance of these cells to glandular atrophy.