Abstract
Purpose : It is generally accepted that glucocorticoids promote gluconeogenesis and enhance the degradation of fat and protein. Further, glucocorticoids are also known to play an essential role in the induction of many enzymes such as tyrosine aminotransferase and aspartate aminotransferase. However, the physiological changes by acute administration of glucocorticoids have not been elucidated systematically. Therefore, acute effects of dexamethasone (DEX) on the plasma energy substrate (glucose, total cholesterol and triglyceride) levels and hematocrit in rats were studied. Methods : 7 weeks old male SD rats (n=16) were used. DEX (dose=2 mg/kg BW) was administered to rats. An equivalent volume of 0.9% NaCl solution was administered to the rats of control (CON) group. Results : Plasma glucose concentrations were 1.2-1.5 times higher than those of the CON in 4 to 34 hrs after administration. Plasma total cholesterol concentrations were also 1.2-1.5 times higher than those of the CON in 6 to 34 hrs after administration. However, plasma triglyceride concentrations were 0.4-0.6 times lower than those of the CON in 4 to 8 hrs, and 1.4 times higher than those of the CON in 34 hours. Hematocrit values showed no significant changes. In conclusion, DEX induced the increase of plasma glucose and total cholesterol levels and the decrease of plasma triglyceride levels, without changing hematocrit values after administration. [Jpn J Physiol 54 Suppl:S233 (2004)]
