Intracerebroventricular injection of neuropeptide Y modifies carbohydrate and lipid metabolism in chicks

The purpose of the present study was to investigate whether intracerebroventricular (ICV) injection of neuropeptide Y (NPY) affects heat production (HP), body temperature, and plasma concentrations of metabolic fuels in chicks. ICV injection of NPY (0, 188 or 375 pmol) did not affect HP, but significantly lowered respiratory quotient as well as the rectal temperature. These data suggest that the energy sources for HP were modified by NPY in the body. This idea was confirmed by subsequent experiments in which ICV injection of NPY significantly reduced plasma glucose and triacylglycerol concentrations but increased non-esterified fatty acid concentrations. The effect of NPY on the utilization of metabolic fuels was not associated changes in plasma catecholamine and corticosterone concentrations. In summary, the present study demonstrated that central NPY modifies peripheral carbohydrate and lipid metabolism in chicks.