alexa Effects of dopaminergic drugs on the sympathoadrenal system.
Engineering

Engineering

Journal of Biosensors & Bioelectronics

Author(s): DamaseMichel C, Montastruc JL, Tran MA

Abstract Share this page

Abstract Several studies have suggested that dopamine (DA) plays a major role in cardiovascular functions. Dopaminergic receptors have been found on sympathetic nerve terminals (DA2), kidney (DA1, DA2), vascular smooth muscle (DA1) as well as on sympathetic ganglia (DA1, DA2) and adrenal gland (DA1, DA2). Previous studies have shown that DA2 receptor stimulation by a specific DA2 agonist, quinpirole (1) elicits a peripheral depressor action (decreased blood pressure) and a central pressor component involving an increase in both sympathetic tone and vasopressin release and (2) does not affect under in vivo conditions adrenal catecholamine release. The present study investigates the effects of fenoldopam, a specific DA1 receptor agonist on both cardiovascular responses and catecholamine release from the adrenal medulla. In conscious normal dogs, fenoldopam (10, 20 and 40 micrograms/kg i.v.) elicited a decrease in blood pressure and a marked increase in heart rate associated with a rise in plasma catecholamine levels. The increase in heart rate is only due to baroreflex mechanism since fenoldopam (conversely to DA2 receptor agonists like quinpirole) does not exert a central excitatory component (as shown by the absence of cardiovascular effects after intracisternal injection). Moreover, in sinoaortic denervated dogs (i.e. animals deprived from baroreflex pathways), the decrease in arterial blood pressure was more important than in normal dogs. Heart rate was unchanged. In these animals, DA1 stimulation induced a decrease in sympathetic tone, as shown by the significant fall in plasma noradrenaline levels. These "in vivo" data clearly demonstrate the inhibitory role of ganglionic DA1 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
This article was published in Hypertens Res and referenced in Journal of Biosensors & Bioelectronics

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords