RESUMO
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.
Assuntos
Ácidos Araquidônicos/farmacologia , Canabinoides/farmacologia , Glândula Tireoide/fisiologia , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Cicloexanóis/farmacologia , Endocanabinoides , Masculino , Alcamidas Poli-Insaturadas , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptor CB1 de Canabinoide/fisiologia , Receptor CB2 de Canabinoide/efeitos dos fármacos , Receptor CB2 de Canabinoide/fisiologia , Somatostatina/metabolismo , Sinaptofisina/metabolismo , Glândula Tireoide/efeitos dos fármacosRESUMO
Concentrations of kininogens, prekallikrein, fibrinogen and antigens of protease inhibitors as well as kininase, fibrinolytic and antipapain activities were estimated in blood plasma (or serum) of patients with coronary artery disease (CAD) before and after the exercise test. The study was conducted on 44 subjects with chronic, stable CAD and 54 myocardial infarction patients (15 treated with streptokinase and 39 subjected to primary percutaneous transluminal coronary angioplasty, PTCA). The patients were divided into two subgroups: treated and untreated with angiotensin I-converting enzyme inhibitor (ACE-I), enalapril. Activation of the fibrinolytic system and the prekallikrein during the exercise test was demonstrated. No significant kininogen consumption was observed. A decrease in kininase activity was found. The results suggest the possibilities of endothelial cells contribution to plasminogen activation in CAD patients. Kininogen and kallikrein directly, or through the released kinins, may participate in regulation of endothelial cell hemostatic functions. Conversion of plasminogen to plasmin may undergo under the influence of kallikrein. The bradykinin induces the tissue plasminogen activator (t-PA) secretion, which depends also on the increased blood flow during the exercise test.
