Plasma neuropeptide Y-like immunoreactivity (NPY-LI) and platelet cyclic AMP (cAMP) activity were determined in 13 women with bipolar disorder stabilized on lithium (Li) and 12 matched healthy controls. No differences in plasma NPY-LI were found between the two groups. In euthymic Li-treated bipolar patients, there was an inverse correlation between plasma NPY-LI levels and intracellular cAMP in prostaglandin E1-stimulated platelets. A positive correlation was found between plasma NPY-LI levels and age in both the patient and the control group. Our findings support earlier findings that NPY is capable of inhibiting adenylyl cyclase and that aging is a physiological factor in regulating NPY-LI levels.
Adenylyl Cyclases Adult