Influence of cannabinoids on immunoreactivity of regulatory peptides, produced in rat thyroid C cells; preliminary investigations.

Mammalian tissues contain two types of cannabinoid receptors CB1 and CB2. The aim of our study was an evaluation of the influence of a single i.p. injection of a stable analogue of an endogenous cannabinoid anandamide--R-(+)-methanandamide (2.5 mg/kg) and CP 55,940 (0.25 mg/kg), which is an exogenous agonist of CB1 receptors, on the immunoreactivity of regulatory peptides, produced in rat thyroid C cells: calcitonin, CGRP, somatostatin and synaptophysin. This study indicates that a single injection of cannabinoids: R-(+)-methanandamide and CP 55,940 alters the immunoreactivity of regulatory peptides in thyroid parafollicular cells.