Effects of seasonal and physiological variations on the serum chemistry, vitamins and thyroid hormone concentrations in sheep.

The aim of this study was to investigate the possible effects of the reproductive status and seasonal variations on the serum chemistry and vitamin status and their relationships with the thyroid hormones in Sakiz-Awassi crossbreed sheep. The sheep (n = 34) were divided into two groups. The first group (n = 22) was mated; the second group (n = 12) was not mated. Their serum samples were collected four times a year at the each season and under reproductive status. The periods are 1, early pregnancy (October); 2, late pregnancy (January); 3, lactation (April); and 4, dry season (July). The results of this study indicated that (1) total protein (TP), globulin, cholesterol, creatinine, uric acid and T4/T3 vary with reproductive status but not seasonal variations; (2) alanine aminotransferase, T4, fT4 concentrations in serum vary only with reproductive status; (3) the urea, creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, amylase, albumin, triglyceride, VLDL, Vit A-E, T3 and fT3 concentration could vary with both reproductive status and seasonal variations; (4) the glucose, gamma-glutamyl transpeptidase, folate concentrations were altered neither season of the year nor the reproductive status; (5) a single reference interval for folate, gamma-glutamyl transpeptidase (GGT), glucose, TP, globulin, cholesterol, creatinine, uric acid and T4/T3 can be used for both mated and non-mated sheep because of no differences were found due to the reproductive status. Taking the results together suggests that reproductive status and seasonal variations have to be taken into consideration for a correct interpretation of the serum chemistry values of sheep. Nutritional supplements are required for sheep during certain periods to avoid a decline of their performance, which would then represent consequent economic, loses.

The effect of dexamethasone on gastric mucosal changes following sialoadenectomy in rat.

In this study, dexamethasone-induced gastric lesions were studied in rats that had undergone sialoadenectomy. The ultrastructural changes developed during the study were detected by electron microscopically, while blood serum and stomach epidermal growth factor (EGF) concentrations were measured by RIA. The result of the study showed that gastric lesions were correlated with gastric mucus secretion and both serum and mucosa EGF levels. After the administration of dexamethasone, it was found that sialoadenectomy significantly (p<0.01) raised the incidence of stomach lesions (p<0.01), and a significant increase in mucus secretion was also found. Additionally, the serum and gastric mucosal EGF levels fell after sialoadenectomy when compared to normal rats. The most important gastric mucosal changes were observed in rats treated with dexamethasone and those both sialoadenectomised and treated with dexamethasone.