Vol 62, No 4 (2003)
Short communication
Published online: 2003-09-05
An immunohistochemical study of the thyroid parafollicular (C) cells in rats treated with cannabinoids - preliminary investigations
Folia Morphol 2003;62(4):419-421.
Abstract
The purpose of the present study was to evaluate the effect of a single intraperitoneal
injection of a stable analogue of endogenous cannabinoid anandamide
- R-(+)-methanandamide (2.5 mg/kg) and CP 55,940 (0.25 mg/kg), an
egzogenous CB1 receptor-agonist, on the calcitonin (CT) immunoreactivity of
the thyroid parafollicular (C) cells. Four hours after injection with both cannabinoids
CT immunoreactivity, evaluated with an avidin-biotin peroxidase complex
method by means of rabbit antibodies against CT, was seen to be enhanced
in the parafollicular cells in comparison to those of the control group.
In thyroids taken from cannabinoid-treated rats the majority of follicles, particularly
those located peripherally were large in size, and had low epithelium.
Moreover, dilatation of the blood vessels was observed. These changes were
accompanied by a significant decrease in CT plasma level, without changes in
calcium concentrations. This is the first evidence that a single injection of the
cannabinoids R-(+)-methanandamide and CP 55,940 significantly decreases
the activity of thyroid C cells.
Keywords: thyroid C cellscannabinoidsimmunohistochemistryrats
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