Experimental animal models of diabetes induced either by alloxan or streptozotocin have been used to study aspects of the pathophysiology of this disease. The purpose of this study was to examine the metabolism of glycogen in the submandibular and parotid salivary glands of diabetic rats. Diabetes was induced by an intraperitoneal injection of streptozotocin. Eight weeks after the induction of diabetes, the animals were sacrificed and the submandibular and parotid salivary glands were removed. The glands were analyzed for glycogen concentration, and activities of glycogen synthase and phosphorylase. Although the diabetic rats consumed more food than controls, they had a lower body weight eight weeks after diabetes induction. Glycogen concentration in the submandibular and parotid glands increased by about 27% and 130%, respectively. Glycogen phosphorylase a in the submandibular gland of diabetic rats showed a reduction of between 75% and 68% compared with controls. In parotid glands, phosphorylase a was reduced by between 84% and 79% compared with controls. The increase in the activity of glycogen synthase a (active) varied from 64% to 130% for the submandibular glands and from 75% to 110% for the parotid compared with controls. These results suggest that the diabetic state influences glycogen metabolism in the submandibular and parotid salivary glands of rats.

A homocisteína, formada a partir da metionina hepática, é metabolizada nas vias de desmetilação e de transulfuração, sendo que seus valores plasmáticos e urinários refl etem a síntese celular. Sua determinação, realizada em jejum e após sobrecarga de metionina, caracteriza as diferenças dessas vias metabólicas, principalmente quando de natureza genética. A hiper-homocisteinemia tem sido associada a maior risco de eventos aterotrombóticos, e a literatura sugere associação causal, independente de outros fatores de risco para doença arterial. Diminuição da homocisteína plasmática para valores normais é seguida de redução signifi cante na incidência de doença aterotrombótica. A relação entre homocisteína e o fígado vem adquirindo importância nos dias atuais, uma vez que alterações das lipoproteínas e da depuração de metionina são comuns em pacientes com doença hepática crônica (hepatocelular e canalicular). O tratamento da hiper-homocisteinemia fundamenta-se na suplementação alimentar e medicamentosa de ácido fólico e vitaminas B 6 e B 12 . (49) , porém mais de 40% dos pacientes com doença primária da artéria coronária, cerebrovascular ou vascular periférica têm hiper-homocisteinemia (HHe) (25,51) .

In the chronic carbon tetrachloride intoxication, laminin levels are better correlated with the development of hepatic fibrosis than with portal hypertension.

SummaryObjectives: To determine the plasma homocysteine and von Willebrand factor levels as markers of endothelial dysfunction in rats with diabetes mellitus induced by streptozotocin.Methods: Thirty-five adult male rats (Rattus norvegicus albinus) (weight between 180-200g) were randomized into three groups: control group (n=10), which received no drugs or vehicles; sham group (n=10), which received streptozotocin solution; and diabetic group (n=15), which received streptozotocin. Eight weeks after diabetes mellitus induction, the animals were weighed and anesthesized; blood samples were collected from abdominal aorta for plasma total homocysteine, von Willebrand factor and glucose levels. Conclusion: Reduced homocysteine levels and increased von Willebrand factor levels were observed in diabetes mellitus induced by streptozotocin; nevertheless, there were no correlations between them and with final glucose levels.