Obesity increases the risk of respiratory diseases that reduce respiratory chemosensitivity, such as Obesity Hypoventilation Syndrome and sleep apnea. Recent evidence suggests that obesity-related changes in the brain, including alterations in melanocortin signaling via the melanocortin-4 receptor (MC4R), may underly altered chemosensitivity. Setmelanotide, an MC4R agonist, causes weight loss in both humans and animal models.
View Article and Find Full Text PDFIntermittent hypoxia (IH), a key characteristic of obstructive sleep apnea, is independently associated with cardiometabolic impairment. While endogenous leptin levels may provide cardioprotective effects against hypoxia, leptin resistance is common among obese individuals presenting with obstructive sleep apnea. Here, we assessed left ventricle (LV) function using M-mode echocardiography in lean wild-type, calorically-restricted , and obese mice before and after 6 days of IH to determine how obesity and intermittent hypoxia interact to affect cardiac function independent of leptin signaling.
View Article and Find Full Text PDFSleep apnea is a common sleep disorder characterized by periodic breathing cessation and intermittent hypoxia (IH). Although previous studies have demonstrated that IH alone can influence metabolic outcomes such as body weight, it remains unclear how the timing of IH can specifically affect these outcomes. Here, we examine how pairing 10-h periods of IH to either the animals' resting phase (e.
View Article and Find Full Text PDFBromocriptine, a dopamine D2 receptor agonist originally used for the treatment of hyperprolactinemia, is largely successful in reducing hyperglycemia and improving glucose tolerance in type 2 diabetics. However, the mechanism behind bromocriptine's effect on glucose intolerance is unclear. Here, we tested three hypotheses, that bromocriptine may exert its effects on glucose metabolism by ) decreasing prolactin secretion, ) indirectly increasing activity of key melanocortin receptors in the central nervous system, or ) improving/restoring circadian rhythms.
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