Chronic cardiovascular effects of central vasopressin in conscious rats.
To clarify the cardiovascular effects of central vasopressin (AVP), a chronic intracerebroventricular (ICV) infusion of AVP was performed in conscious Wistar normotensive rats. Animals were divided into 3 groups: 1) AVP 1 ng/hr (Low), 2) AVP 100 ng/hr (High), and 3) saline (control) ICV infusion. After a 6 day control period, AVP or saline was continuously infused into the lateral cerebroventricle at a rate of 1 microliter/hr using osmotic minipump for 7 days. As a result, a dose-related elevation of AVP concentration in CSF was achieved. Systolic blood pressure in both Low and High AVP infusion was slightly (7-12 mmHg) but significantly higher than that in control. ICV infusion of AVP did not alter urine volume, electrolytes excretion or osmolality, and AVP vascular antagonist injected intravenously failed to affect mean arterial pressure. Furthermore, plasma catecholamines and renin activity did not differ significantly among the groups. Thus, chronic ICV infusion of AVP induced the elevation of blood pressure, which is due to centrally mediated effect of AVP.
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka City, Japan.
T
T
Tsuchihashi
Y
Y
Takata
Y
Y
Tomita
S
S
Takishita
Y
Y
Nakao
K
K
Kobayashi
M
M
Fujishima
D000818:Animals; D001127:Arginine Vasopressin / Q000008:administration & dosage* / Q000097:blood / Q000134:cerebrospinal fluid; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology; D002319:Cardiovascular System / Q000187:drug effects*; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D007260:Infusion Pumps; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012084:Renin-Angiotensin System / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects
D006584:Hexamethonium Compounds; D001127:Arginine Vasopressin; D018738:Hexamethonium; D002216:Captopril