Chronic cold stress (4 degrees C) produced a sustained increase in mea
n arterial pressure in both normotensive and borderline hypertensive r
ats (BHR). The high blood pressure in BHRs was significantly reversed
by a neuropeptide Y (NPY) Y-1 receptor antagonist suggesting that NPY
is involved in mediating stress-induced hypertension. Corresponding in
creases in adrenal NPY messenger RNA and NPY immunoreactivity were fou
nd during the stress; furthermore, chronic cold stress also potentiate
d the presser response of rats to a subsequent acute stress test in wh
ich NPY has been shown to play a role. These results suggest that chro
nic cold stress-induced hypertension is mediated by elevated NPY relea
se and vascular tone as a result of increased NPY gene expression and
storage. (C) 1998 Elsevier Science Inc.