Intracerebroventricular prokineticin 2 infusion may play a role on the hypothalamus-pituitary-thyroid axis and energy metabolism.

• Icv infusion of prokineticin 2 (1.5 nMol) did not alter food and water consumption in rats, but infusion of prokineticin 2 (4.5 nMol) decreased food consumption. • Icv prokineticin 2 (4.5 nMol) infusion reduced the body weight of rats. • Icv prokineticin 2 (4.5 nMol) infusion induced the hypothalamus-pituitary-thyroid (HPT) axis. • Icv prokineticin 2 (4.5 nMol) infusion increased the expression level of PGC-1α and UCP1 genes in white and brown adipose tissue. The hypothesis of this study is to determine the effects of intracerebroventricular (icv) prokineticin 2 infusion on food consumption and body weight and to elucidate whether it has effects on energy expenditure via the hypothalamus-pituitary-thyroid (HPT) axis in adipose tissue. A total of 40 rats were used in the study and 4 groups were established: Control, Sham, Prokineticin 1.5 and Prokineticin 4.5 (n =10). Except for the Control group, rats were treated intracerebroventricularly via osmotic minipumps, the Sham group was infused with aCSF (vehicle), and the Prokineticin 1.5 and Prokineticin 4.5 groups were infused with 1.5 nMol and 4.5 nMol prokineticin 2, respectively. Food and water consumption and body weight were monitored during 7-day infusion in all groups. At the end of the infusion, the rats were decapitated and serum TSH, fT4 and fT3 levels were determined by ELISA. In addition, PGC-1α and UCP1 gene expression levels in white adipose tissue (WAT) and brown adipose tissue (BAT), TRH from rat hypothalamic tissue were determined by real-time PCR. Icv prokineticin 2 (4.5 nMol) infusion had no effect on water consumption but reduced daily food consumption and body weight (p <0.05). Icv prokineticin 2 (4.5 nMol) infusion significantly increased serum TSH, fT4 and fT3 levels when compared to Control and Sham groups (p <0.05). Also, icv prokineticin 2 (4.5 nMol) infusion increased the expression of TRH in the hypothalamus tissue and expression of PGC-1α UCP1 in the WAT and BAT (p <0.05). Icv prokineticin 2 (4.5 nMol) infusion may suppress food consumption via its receptors in the hypothalamus and reduce body weight by stimulating energy expenditure and thermogenesis in adipose tissue through the HPT axis. [ABSTRACT FROM AUTHOR]