Hyperphagia and hyperleptinemia induced by low-protein, high-carbohydrate diet is reversed at a later stage of development in rats

Abstract

This study investigated whether increased food intake after 15 days of low-protein, high-carbohydrate (LPHC) and its normalization in the later period of development change the content of key proteins related to leptin or adiponectin signaling in the hypothalamus. Male rats were divided into five groups: Control groups received a control diet (17% protein, 63% carbohydrate) for 15 (C₁₅) or 45 (C₄₅) days; LPHC groups received an LPHC diet (6% protein, 74% carbohydrate) for 15 (LPHC₁₅) or 45 (LPHC₄₅) days; and Reverse group (R): received LPHC diet for 15 days followed by control diet for another 30 days. The LPHC₁₅ group showed increased adiposity index, leptin level, and adiponectin level, as well as decreased the leptin receptor (ObRb) and pro-opiomelanocortin (POMC) content in the hypothalamus compared with the C₁₅ group. LPHC diet for 45 days or diet reversion (R group) rescued these alterations, except the adiponectin level in LPHC₄₅ rats, which was higher. In summary, LPHC diet reduced hypothalamic leptin action by diminishing ObRb and POMC levels, leading to hyperphagia and adiposity body. Medium-term administration of LPHC diet or reverting to control diet restored the levels of these proteins, thereby improving body lipid mass rearrangement in adulthood.

Key words
adiponectin; hypothalamus; low-protein high-carbohydrate diet; leptin