We studied the effects of intense sympathetic stimulation on the chronotropic responses of the heart to subsequent test stimulations of the cardiac autonomic nerves in dogs anesthetized with a-chloralose. Such intense sympathetic stimulations (which we refer to as "release stimulations") are known to release neuropeptide Y as well as norepinephrine. The changes in cardiac cycle length evoked by...

Within the neuropeptide Y (NPY) family of peptides, pancreatic polypeptide is the most divergent across species. It differs in 20 of 36 positions between human and chicken. In mammals, it binds primarily to the Y4 receptor, to which NPY and peptide YY (PYY) bind with lower affinities. Because of these large sequence differences in pancreatic polypeptide, we decided to characterise the chicken Y...

Neuropeptide Y, a neuropeptide abundantly expressed in the brain, has been implicated in the regulation of the hypothalamo-pituitary-somatotropic axis and the hypothalamo-pituitary-gonadotropic axis. Elevated hypothalamic neuropeptide Y expression, such as that occurs during fasting, is known to inhibit both of these axes. However, it is not known which Y receptor(s) mediate these effects. Here...