TY - JOUR
T1 - Area postrema ablation and vascular reactivity in deoxycorticosterone-salt-treated rats
AU - Bruner, Cathy A.
AU - Mangiapane, Michael L.
AU - Fink, Gregory D.
AU - Clinton Webb, R.
PY - 1988/6
Y1 - 1988/6
N2 - In rats, central administration of the neurotoxin 6-hydroxydopamine prevents hypertension and certain functional vascular changes after deoxycorticosterone (DOC)-salt treatment. In this study, the effect of electrolytic ablation of the area postrema on blood pressure and vascular reactivity in DOC-salt-treated rats was examined. Four treatment groups of rats were studied (n=5 in each): area postrema lesion, DOC-salt (DOC pivalate, 5 mg/wk s.c. for 5 weeks); sham lesion, DOC-salt; area postrema lesion, control; and sham lesion, control. Helically cut strips of carotid artery, aorta, and mesenteric artery were prepared for isometric force recording. Area postrema lesion attenuated hypertension in DOC-salt rats (mean arterial pressure, 107 vs 123 mm Hg in area postrema lesion and sham lesion rats, respectively; chronic aortic catheter). Vascular strips from sham lesion-DOC-salt rats were more sensitive to KC1, ouabain, and serotonin than were those from sham lesioncontrol rats. These changes in vascular reactivity also were observed in area postrema lesion-DOCsalt rats. DOC treatment in rats on a normal sodium intake did not result in hypertension or increased vascular reactivity. In summary, integrity of the area postrema is necessary for hypertension, but not for changes in vascular reactivity, in DOC-salt rats. It appears that 1) changes in vascular reactivity may be necessary, but they are not sufficient to produce DOC-salt hypertension, and 2) if these vascular changes are secondary to a central nervous system effect, they are mediated by a pathway distinct from the area postrema.
AB - In rats, central administration of the neurotoxin 6-hydroxydopamine prevents hypertension and certain functional vascular changes after deoxycorticosterone (DOC)-salt treatment. In this study, the effect of electrolytic ablation of the area postrema on blood pressure and vascular reactivity in DOC-salt-treated rats was examined. Four treatment groups of rats were studied (n=5 in each): area postrema lesion, DOC-salt (DOC pivalate, 5 mg/wk s.c. for 5 weeks); sham lesion, DOC-salt; area postrema lesion, control; and sham lesion, control. Helically cut strips of carotid artery, aorta, and mesenteric artery were prepared for isometric force recording. Area postrema lesion attenuated hypertension in DOC-salt rats (mean arterial pressure, 107 vs 123 mm Hg in area postrema lesion and sham lesion rats, respectively; chronic aortic catheter). Vascular strips from sham lesion-DOC-salt rats were more sensitive to KC1, ouabain, and serotonin than were those from sham lesioncontrol rats. These changes in vascular reactivity also were observed in area postrema lesion-DOCsalt rats. DOC treatment in rats on a normal sodium intake did not result in hypertension or increased vascular reactivity. In summary, integrity of the area postrema is necessary for hypertension, but not for changes in vascular reactivity, in DOC-salt rats. It appears that 1) changes in vascular reactivity may be necessary, but they are not sufficient to produce DOC-salt hypertension, and 2) if these vascular changes are secondary to a central nervous system effect, they are mediated by a pathway distinct from the area postrema.
KW - Aorta
KW - Arterial pressure
KW - Carotid artery
KW - Hypertension
KW - Mesenteric artery
KW - Ouabain
KW - Serotonin
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U2 - 10.1161/01.HYP.11.6.668
DO - 10.1161/01.HYP.11.6.668
M3 - Article
C2 - 3391678
AN - SCOPUS:0023680454
SN - 0194-911X
VL - 11
SP - 668
EP - 673
JO - Hypertension
JF - Hypertension
IS - 6
ER -