Fuzi-Lizhong pill compensates hypothyroid-hypothermia via ghrelin release

Ethnopharmacological relevance: Fuzi-Lizhong pill (FLZ) is a traditional Chinese medicine for treating patients with Spleen Yang deficient syndrome. Ghrelin, a peptide with 28 amino acid residues, plays multiple roles in thermogenesis. This study aims to explore FLZ regulating ghrelin to compensate hypothermia in rats with hypothyroid and indigestion. Materials and methods: In litter-matched rats, hypothermia was developed with both thyroidectomy at d(1) and interscapular brown adipose (IBA) removal at d(42), indigestion was induced with both high fat diet and fasting-feeding cycle from d(56); the littermates with hypothermia and indigestion were administrated with FLZ from d(70). Adaptive thermogenesis, thyroid hormones, metabolites, ghrelin dynamics were measured at d(98). Results: The results showed that plasma ghrelin levels were inversely correlated with the gastric ghrelin levels and adaptive thermogenesis in rats undergone both thyroidectomy and IBA removal. Fatty diet and FLZ enhanced the increase of plasma ghrelin of hypothyroid rats. These were supported by the changes of plasma thyroid related hormones, plasma metabolites, gastric ghrelin mRNA and protein, and the effects of fatty diet or FLZ. Conclusions: Our results suggest that more ghrelin release compensate chronic hypothermia in rats with both hypothyroidism and indigestion. It could explain the mechanisms of FLZ in relieving chronic hypothermia. (C) 2013 Elsevier Ireland Ltd. All rights reserved.