Attenuated cardiovascular and sympathetic nerve responses to aortic nerve stimulation in DOCA-salt hypertensive rats.
In order to verify, whether baroreflex sensitivity is changed centrally in DOCA-salt hypertension, the left aortic depressor nerve (ADN) was electrically stimulated in DOCA-salt hypertensive rats. After 3 weeks, tail-cuff systolic pressure was significantly higher in DOCA-salt treated rats than in untreated rats (169 +/- 4 versus 130 +/- 4 mmHg, respectively; P less than 0.001). After cutting both ADN and the carotid sinus nerves, the central cut end of the left ADN was electrically stimulated and frequency dependent depressor, bradycardic and sympatho-inhibitory responses were elicited in both control and DOCA-salt hypertensive rats. However, these responses were significantly smaller in DOCA-salt hypertensive rats than in normotensive controls. Bradycardic and sympatho-inhibitory responses to i.v. injection of norepinephrine were also blunted in DOCA-salt hypertensive rats. These findings suggest that baroreflexes were centrally attenuated in DOCA-salt hypertensive rats and possibly contribute to overall baroreflex attenuation.
Takeda
K
K
Second Department of Medicine, Kyoto Prefectural University of Medicine, Japan.
Nakamura
Y
Y
Okajima
H
H
Hayashi
J
J
Kawasaki
S
S
Lee
L C
LC
Sasaki
S
S
Nakagawa
M
M
D000818:Animals; D001011:Aorta / Q000294:innervation; D001794:Blood Pressure; D003900:Desoxycorticosterone / Q000009:adverse effects*; D004558:Electric Stimulation; D006339:Heart Rate; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D011311:Pressoreceptors / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012021:Reflex, Abnormal / Q000503:physiopathology*; D012982:Sodium, Dietary / Q000009:adverse effects*; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D012982:Sodium, Dietary; D003900:Desoxycorticosterone