Effects of chronic dexamethasone administration on hyperglycemia and insulin release in goats

Abstract

BackgroundDexamethasone (Dex), a synthetic glucocorticoid, is among the most commonly used drugs worldwide in animals and humans as an anti-inflammatory and immunosuppressive agent. GC has profound effects on plasma glucose level and other metabolic conditions. However, the effect of prolonged use of Dex on glucose metabolism in ruminants is still unclear.ResultsTen goats were randomly assigned to two groups: the control goats were injected with saline, and the Dex-treated goats were intramuscularly injected daily for 21 d with 0.2 mg/kg Dex. The results showed that plasma glucose and insulin concentrations were significantly increased after Dex administration (P < 0.05). Additionally, the content of hepatic glycogen was also markedly increased in Dex-treated goats (P < 0.01), while the content of glycogen in dorsal longissimus was unchanged by Dex (P > 0.05). The expression of several key genes, involved in blood glucose regulation, was detected by real-time PCR in the small intestine, skeletal muscle and liver. The expression of glucose transporter type 2 (GLUT2), sodium-glucose transporter 1 (SGLT1) and sodium-potassium ATPase (Na-K/ATPase) in the small intestine were generally increased by Dex, and GLUT2 mRNA expression was significantly up-regulated (P < 0.05). In liver, the expression of genes involved in gluconeogenesis including glucose-6-phosphatase catalytic subunit (G6PC), cytosolic form of phosphoenolpyruvate carboxykinase (PCK1) and pyruvate carboxylase (PC), were significantly down-regulated by Dex. However, the protein expression levels of PCK1 & PCK2 were significantly increased by Dex, suggesting a post-transcriptional regulation. In dorsal longissimus, the mRNA expression of genes associated with gluconeogenesis and the insulin signaling pathway were generally up-regulated by Dex, but the mRNA expression of two markers of muscle atrophy, namely F-box protein 32 (FBXO32/Atrogin1) and muscle RING-finger protein 1 (MuRF1), was not altered by Dex.ConclusionsTaken together, these results indicate that chronic administration of a low dosage of Dex induces hyperglycemia mainly through gluconeogenesis activation in the goat liver.

Effect of Parkia biglobosa seed on lipid profile of dexamethasone-treated pregnant rats

“…Exposure of animals to dexamethasone was observed to significantly (p<0.05) increased the concentration of plasma glucose when compared with the control as well as animals treated with P. biglobosa only (figure 1). This corresponds to the findings of Niu et al [19] who treated goats with dexamethasone. It also agrees with the observation of Hans et al [20] who studied the blood glucose concentration profile after 10 mg dexamethasone in non-diabetic and type 2 diabetic patients undergoing abdominal surgery.…”

Molecular Mechanism Induced by Beta-Glucans from Maitake to Recover T Cell-Subpopulations during Immunosuppression

“…Moreover, in the hematological analysis of mouse peripheral blood in various experimental conditions, we have observed that the dexamethasone (immunodepleted) group had many giant cells of immature appearance compatible with megakaryocytes, while the condition with Maitake + dexamethasone group presented low number of immature cells, in addition to increasing number of lymphocytes, PMN neutrophils, basophils, and some megakaryocytes. In turn, the group dexamethasone + verapamil + Maitake exhibited megakaryocytes and mast cells in degranulation [38]. The healthy control group did not have immature cells, with clustered platelets, lymphocytes, neutrophils, and monocytes observed.…”

Elevated thyroid hormone caused by high concentrate diet participates in hepatic metabolic disorders in dairy cows

“…The studies on dairy goats also showed that high concentrate diet signi cantly elevated plasma cortisol and glucocorticoid receptor protein expression in the liver, indicating animals under a state of stress (Dong et al, 2013, Jia et al, 2014. Our previous studies on goats con rmed that intramuscular injection dexamethasone, a synthetic glucocorticoid, signi cantly increased liver glycogen deposition, accompanied with increased expression of proteins related to gluconeogenesis in the liver (Niu et al, 2018).…”