5-Carboxamidotryptamine attenuates the development of deoxycorticosterone acetate-salt hypertension in rats.
The effect of chronic i.v. infusion of the 5-HT1 receptor agonist, 5-carboxamidotryptamine (5-CT), was evaluated during the development of deoxycorticosterone acetate-salt (DOCA-salt) hypertension in rats over 4 weeks. Vehicle-treated (n = 10) Sprague-Dawley rats given DOCA (100 mg/kg, s.c.) and 1% saline as drinking fluid developed hypertension with systolic blood pressure reaching 194.6 +/- 8.99 mm Hg at 27 days. In DOCA-salt rats treated with 5-CT infusions (15.0 micrograms/kg per day, n = 10) for 4 weeks via osmotic minimpumps, systolic blood pressure was significantly lower by 41.7 mm Hg at day 27 when compared to vehicle-treated DOCA-salt rats. Systolic blood pressure values on day 27 in 5-CT-treated DOCA-salt rats were however greater than those in vehicle-treated control rats which were not given DOCA. Systolic blood pressure in 5-CT-treated DOCA-salt rats was significantly lower by day 7 compared to vehicle-treated DOCA-salt rats and remained lowered for the rest of the observation period. Heart rate was significantly greater in 5-CT-treated DOCA-salt rats on day 7 when compared to vehicle-treated DOCA-salt rats. Baroreflex sensitivity on day 28 was significantly greater in 5-CT-treated DOCA-salt rats as compared to vehicle-treated DOCA-salt rats. On day 28, hypotensive responses to hexamethonium (20 mg/kg) in 5-CT-treated DOCA-salt rats were markedly reduced compared to those in vehicle-treated DOCA-salt rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Balasubramaniam
G
G
Department of Pharmacology, Faculty of Medicine, National University of Singapore.
Lee
H S
HS
Mah
S C
SC
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone; D004573:Electrolytes / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000517:prevention & control*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D012965:Sodium Chloride
D004573:Electrolytes; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D003900:Desoxycorticosterone; D012965:Sodium Chloride; C047087:5-carboxamidotryptamine