Increase of urocortin-like immunoreactivity in the supraoptic nucleus of Dahl rats given a high salt diet

Urocortin-like immunoreactivity (Ucn-LI) in the supraoptic nucleus (SON) of Dahl rats was examined. Dahl salt-sensitive (S) rats fed with a high salt diet developed hypertension. Numbers of Ucn-LI neurons in the SON in Dahl S on a high salt diet were markedly increased, compared with those in Dahl s alt-resistant (R) rats on the same. Sporadic Ucn-LI neurons were found in t he SON of both Dahl S and R on a normal diet. Numbers of Ucn-LI neurons in the SON of spontaneously hypertensive rat (SHR) and stroke-prone SHR, genet ic models of hypertension, and control rats (Sprague-Dawley and Wistar-Kyot o) were similar. These results suggest that Ucn in the SON is associated wi th salt loading-induced hypertension rather than spontaneous hypertension. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.