Assuntos
Arteriosclerose/patologia , Vasos Coronários/patologia , Modelos Animais de Doenças , Miocárdio/patologia , Adolescente , Adulto , Idoso , Envelhecimento , Animais , Aorta/crescimento & desenvolvimento , Aorta/patologia , Artérias/metabolismo , Artérias/ultraestrutura , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Bovinos , Criança , Pré-Escolar , Endotélio/ultraestrutura , Estro , Feminino , Glicosaminoglicanos/metabolismo , Humanos , Lactente , Metabolismo dos Lipídeos , Lipoproteínas/metabolismo , Pessoa de Meia-IdadeRESUMO
The distribution of mast cells (MCs) and their participation in mural glycosaminoglycan (GAGs) metabolism was investigated in the left coronary arteries of 40 5-10 year old Holstein-Friesian cows. Usually MCs were present in the outer media and adventitia, but they also occurred in areas where local circumstances required their support. The distribution of MC was related to local conditions, with regard to the utilization of the contents of their granules. Large and small MCs were present; some of them stained darker with toluidine blue than others. MCs liberated their contents by expelling whole granules or by granulolysis. Granular release was associated with the metabolism of hyaluronic acid and granulolysis with heparan sulphates. Activity of mural MCs and GAGs was influenced by hormones regulating the sexual cycle. The curves obtained from MCs counts and GAGs levels at different stages of the sexual cycle indicate that MC were taking part in the GAG metabolism. MC also participated in the production of hyaluronic acid and heparan sulphates. Any disorder of the metabolism of mural GAG characterized by an increase of heparan sulphates promoted under certain circumstances the development of histochemically identifiable, primary biochemical lesions of the arterial mesenchyme.