AJP - Heart and Circulatory Physiology, Vol 242, Issue 1 37-H43, Copyright © 1982 by American Physiological Society
Acute interaction of vasopressin and neurogenic mechanisms in DOC-salt hypertension
H. Matsuguchi and P. G. Schmid
We investigated the relative role of vasopressin and neurogenic factors in
the control of vascular resistance in rats treated with
desoxycorticosterone (DOC) and salt and in control rats. DOC-salt-treated
rats had elevated hindquarter vascular resistance (P less than 0.05).
Vasopressin and neurogenic tone contributed significantly (P less than
0.05) to increased resistance. Vasodilator responses to a specific
vasopressin antagonist, I-deaminopenicillamine, 4-valine, 8-D-arginine
vasopressin (dPVDAVP), and lumbar sympathectomy in separate DOC-salt groups
accounted for 40 +/- 5 (SE) and 43 +/- 6%, respectively, of the total
vasodilator capacity. In contrast, corresponding responses to dPVDAVP and
lumbar sympathectomy in control rats were smaller (P less than 0.01), were
significantly different (P less than 0.05), and accounted for 8 +/- 3 and
20 +/- 3%, respectively, of the total vasodilator capacity. Effects of
dPVDAVP compared in innervated hindquarters of DOC-salt-treated and control
rats were greater in DOC-salt-treated rats (P less than 0.001); in the
denervated hindquarters the effects of dPVDAVP were similar in
DOC-salt-treated and control rats. Therefore, effects of vasopressin on
vascular resistance were augmented in DOC-salt-treated hypertensive rats;
furthermore this augmented effect was dependent on an intact innervation.
