[Nicardipine attenuates the sympathetic reflex of orthostatism: do dihydropyridine-sensitive calcium channels regulate noradrenaline release?].
Twelve hypertensive subjects were treated for 2 weeks with the dihydropyridine calcium channel antagonist nicardipine (40 mg daily) according to a double-blind, placebo-controlled study protocol. Nicardipine treatment significantly decreased systolic and diastolic blood pressure and increased plasma noradrenaline levels measured at supine rest. However, the treatment significantly inhibited the physiological increase of circulating neurotransmitter following sympathetic stimulation induced by orthostatism. These results suggest that dihydropyridine-sensitive calcium channels may modulate the noradrenaline release from nerve terminals of the peripheral sympathetic nervous system.
Istituto di Cardiologia, Università degli Studi, Cagliari.
G
G
Mercuro
Z L
ZL
Rossetti
L
L
Lai
M R
MR
Manca
G
G
Longu
M
M
Ruscazio
A
A
Cherchi
D000328:Adult; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000008:administration & dosage / Q000494:pharmacology*; D009638:Norepinephrine / Q000097:blood / Q000378:metabolism*; D011187:Posture / Q000502:physiology*; D012018:Reflex / Q000187:drug effects* / Q000502:physiology; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000503:physiopathology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009529:Nicardipine; D009638:Norepinephrine
La nicardipina attenua il riflesso simpatico dell'ortostatismo: i canali al calcio diidropiridino-sensibili regolano la liberazione di noradrenalina?