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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Anorexia, Dietary Fats, Dose-Response Relationship, Drug, Drug Implants, Estradiol, Hypothalamic Hormones, Leptin, Male, Melanins, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Obese, Pituitary Hormones.
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Is estradiol-induced anorexia independent of leptin and melanin-concentrating hormone? Context: Treatment of male rodents with estradiol (E2) is associated with anorexia and weight loss by poorly understood mechanisms. We examined the role of the orexigenic hypothalamic peptide melanin-concentrating hormone (MCH) and the appetite-inhibiting, fat-derived hormone leptin in mediating E2-induced anorexia. We studied the effect of E2 treatment (implantation of either E2 pellet or matching placebo) in male C57Bl/6J mice, as well as in a lean mouse model (MCH knockout mice) and an obese model (leptin-deficient ob/ob mice). We also studied the effect of E2 treatment in the context of high-fat diet. We confirmed E2 dose-dependent anorexia in male wild type mice fed a normal chow diet. E2 treatment was associated with a significant decrease in body fat, serum leptin levels, and arcuate hypothalamic proopiomelanocortin expression. E2-implanted mice also showed increased hypothalamic neuropeptide Y and MCH expression. As MCH has been implicated in E2-induced hypophagia, we performed E2 pellet implantation in MCH knockout mice and observed hypophagia and weight loss, indicating that MCH is not an essential mediator of E2-induced anorexia. E2-implanted ob/ob mice also had hypophagia and weight loss, indicating that leptin is not essential for E2-induced anorexia. High-fat diet significantly exacerbated the effect of E2 treatment, leading to a 99.6% decrease in food intake at 48 hours and a 30% loss of body weight within 1 week.
assistant
The anorectic effects of E2 were independent of MCH and leptin. Our results suggested that E2 may have effects on nutrient preferences. Final Decision: yes