Caffeine enhances the slow-pressor response to angiotensin II in rats. Evidence for a caffeine-angiotensin II interaction with the sympathetic nervous system.
AUTOR(ES)
Ohnishi, A
RESUMO
The purpose of this study was to determine if caffeine augments the slow-pressor response to chronic low-dose infusions of angiotensin II (AII) or the rapid-pressor response to acute infusions of AII. AII was infused (125 ng/min i.p.) for 12 d via mini-osmotic pumps in four groups of rats: group I, intact rats not treated with caffeine (n = 9); group II, intact rats treated with caffeine (0.1% in drinking water, n = 9); group III, rats previously sympathectomized with 6-hydroxydopamine, but not treated with caffeine (n = 10); and group IV, rats previously sympathectomized with 6-hydroxydopamine and treated with caffeine (n = 10). Chronic low-dose AII infusions slowly elevated systolic blood pressure in all groups. Caffeine greatly augmented this slow-pressor response to AII in intact animals; however, caffeine failed to enhance AII-induced hypertension in sympathectomized rats. Caffeine pretreatment did not enhance the rapid-pressor response to acute intravenous infusions of AII. We conclude that caffeine augmented the slow-pressor effect of chronic low-dose infusions of AII via a mechanism that involved the sympathetic nervous system.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=442195Documentos Relacionados
- The relationship of the renal vascular activity of angiotensin II to the autonomic nervous system.
- Changes in glomerular hemodynamic response to angiotensin II after subacute renal denervation in rats.
- Evidence for descending tonic inhibition specifically affecting sympathetic pathways to the kidney in rats.
- A Study of Angiotensin II Pressor Response throughout Primigravid Pregnancy
- Role of the sympathetic nervous system in the renal response to hemorrhage