Treatment with an SSRI antidepressant restores hippocampo-hypothalamic corticosteroid feedback and reverses insulin resistance in low-birth-weight rats.

Low birth weight (LBW) is associated with type 2 diabetes and depression, which may be related to prenatal stress and insulin resistance as a result of chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. We examined whether treatment with a selective serotonin reuptake inhibitor [escitalopram (ESC)] could downregulate HPA axis activity and restore insulin sensitivity in LBW rats. After 4-5 wk of treatment, ESC-exposed LBW (SSRI-LBW) and saline-treated control and LBW rats (Cx and LBW) underwent an oral glucose tolerance test or a hyperinsulinemic euglycemic clamp to assess whole body insulin sensitivity.

Evaluation of the relationship between hyperinsulinaemia and myocardial ischaemia/reperfusion injury in a rat model of depression.

Major depression is associated with medical co-morbidity, such as ischaemic heart disease and diabetes, but the underlying pathophysiological mechanisms remain unclear. The FSL (Flinders Sensitive Line) rat is a genetic animal model of depression exhibiting features similar to those of depressed individuals. The aim of the present study was to compare the myocardial responsiveness to I/R (ischaemia/reperfusion) injury and the effects of IPC (ischaemic preconditioning) in hearts from FSL rats using SD (Sprague-Dawley) rats as controls and to characterize differences in glucose metabolism and insulin sensitivity between FSL and SD rats.

Metformin induces cardioprotection against ischaemia/reperfusion injury in the rat heart 24 hours after administration.

The UK Prospective Diabetes Study demonstrated that the hypoglycaemic drug metformin is associated with a reduction in cardiovascular events in a group of obese type 2 diabetes patients. The energy sensing enzyme AMP-activated protein kinase (AMPK) has been indicated to play an important protective role in the ischaemic heart and is activated by metformin. The aim of this study was to determine whether a single dose of metformin protects the myocardium against experimentally induced ischaemia 24 hr after the administration, and furthermore to determine whether a single dose of metformin results in an acute increase in myocardial AMPK activity.

Long-term AICAR administration and exercise prevents diabetes in ZDF rats.

Lifestyle interventions including exercise programs are cornerstones in the prevention of obesity-related diabetes. The AMP-activated protein kinase (AMPK) has been proposed to be responsible for many of the beneficial effects of exercise on glucose and lipid metabolism. The effects of long-term exercise training or 5-aminoimidazole-4-carboxamide-1-beta-d-riboruranoside (AICAR) treatment, both known AMPK activators, on the development of diabetes in male Zucker diabetic fatty (ZDF) rats were examined.

Effects of AICAR and exercise on insulin-stimulated glucose uptake, signaling, and GLUT-4 content in rat muscles.

Physical activity is known to increase insulin action in skeletal muscle, and data have indicated that 5'-AMP-activated protein kinase (AMPK) is involved in the molecular mechanisms behind this beneficial effect. 5-Aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) can be used as a pharmacological tool to repetitively activate AMPK, and the objective of this study was to explore whether the increase in insulin-stimulated glucose uptake after either long-term exercise or chronic AICAR administration was followed by fiber-type-specific changes in insulin signaling and/or changes in GLUT-4 expression. Wistar rats were allocated into three groups: an exercise group trained on treadmill for 5 days, an AICAR group exposed to daily subcutaneous injections of AICAR, and a sedentary control group.

Long-term AICAR administration reduces metabolic disturbances and lowers blood pressure in rats displaying features of the insulin resistance syndrome.

The insulin resistance syndrome is characterized by several risk factors for cardiovascular disease. Chronic chemical activation of AMP-activated protein kinase by the adenosine analog 5-aminoimidazole-4-carboxamide-1-beta -D-ribofuranoside (AICAR) has been shown to augment insulin action, upregulate mitochondrial enzymes in skeletal muscles, and decrease the content of intra-abdominal fat. Furthermore, acute AICAR exposure has been found to reduce sterol and fatty acid synthesis in rat hepatocytes incubated in vitro as well as suppress endogenous glucose production in rats under euglycemic clamp conditions.