[3H]5-hydroxytryptamine uptake and release in cat cerebral arteries.
1. Field electrical stimulation induced tritium release from cat cerebral arteries preincubated with [3H]serotonin (5-HT). 2. This release was markedly reduced by tetrodotoxin (0.8 microM), B-HT 920 (1 microM), denervation with 6-OH-dopamine (6-OHDA) and OCa2+, and increased by phentolamine (1 microM) and phorbol 12,13-dibutyrate (1 and 3 microM). 3. 5-HT (10 and 100 microM) and NA (0.1, 1 and 10 microM) caused concentration-dependent tritium release in control arteries, but not in those denervated with 6-OHDA. 4. [3H]5-HT uptake was greatly reduced by preincubation of arteries with cocaine (10 microM), ouabain (100 microM) or denervation with 6-OHDA. 5. 5-HT did not amplify contractions elicited by noradrenaline (NA) in middle cerebral arteries. 6. These data indicate: (1) 5-HT is mainly accumulated in adrenergic nerve endings; (2) 5-HT release is modulated by presynaptic alpha 2-adrenoceptors; (3) protein kinase C of perivascular adrenergic nerve endings participates in 5-HT release, and (4) 5-HT did not amplify NA responses.
Barrús
M T
MT
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid, Spain.
Balfagón
G
G
Salaíces
M
M
Marín
J
J
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D002415:Cats; D002536:Cerebral Arteries / Q000378:metabolism; D003042:Cocaine / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism*; D013563:Sympathectomy, Chemical; D013779:Tetrodotoxin / Q000494:pharmacology
D001381:Azepines; D012701:Serotonin; D015240:Phorbol 12,13-Dibutyrate; D013779:Tetrodotoxin; D010042:Ouabain; C024763:talipexole; D011493:Protein Kinase C; D003042:Cocaine; D009638:Norepinephrine; D010646:Phentolamine