Cerebrovascular smooth muscle culture. II. Characterization of adrenergic receptors linked to adenylate cyclase
| Autor: | Barbara Wroblewska, Joliet Bembry, Maria Spatz, Nancy Merkel |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
medicine.medical_specialty
Adrenergic receptor Adrenergic beta-Antagonists Adrenergic Propranolol Biology General Biochemistry Genetics and Molecular Biology Muscle Smooth Vascular Norepinephrine (medication) Phentolamine Internal medicine Receptors Adrenergic beta medicine Cyclic AMP Animals General Pharmacology Toxicology and Pharmaceutics Practolol Adrenergic alpha-Antagonists Cells Cultured Brain General Medicine Adrenergic beta-Agonists Receptors Adrenergic alpha Yohimbine Rats Receptors Adrenergic Epinephrine Endocrinology Adrenergic alpha-Agonists medicine.drug Adenylyl Cyclases |
| Zdroj: | Life sciences. 34(8) |
| ISSN: | 0024-3205 |
| Popis: | Cultured and propagated smooth muscle cells contain adenylate cyclase (AC) responsive to catecholamines and their analogues. Isoproterenol and zinterol were the most effective stimulants of AC activity with EC50 = 8.5 X 10(-8)M. They were followed by epinephrine, phenylephrine and norepinephrine (EC50 = 7.5 X 10(-7)M, 6.5 X 10(-6)M and 4 X 10(-6)M, respectively). When the selective antagonists for beta 1 and beta 2 receptors (beta 1-type practolol and atenolol, beta 1/beta 2-type propranolol and beta 2-type butoxamine) were tested against isoproterenol, epinephrine and norepinephrine stimulation of AC activity, the beta 1 in contrast to beta 2 antagonists were found ineffective. The alpha-blockers (phentolamine alpha 1/alpha 2-type antagonists) and yohimbine (alpha 2-type antagonist) alone or in the presence of propranolol did not significantly inhibit the catecholamine-induced enhancement of cAMP formation. On the other hand, prazosine (alpha 1-type antagonist) blocked the stimulatory effect of epinephrine and norepinephrine on AC system. Similarly, the alpha 2-agonist, clonidine, did not affect the catecholamines' stimulated AC activity while alpha 1 agonist, phenylephrine, induced an additive enhancement of norepinephrine production of cAMP. The findings of beta-2- and alpha-1-type adrenergic receptors in the cultured cerebrovascular smooth muscle provide additional support for the implicated involvement of adrenergic innervation in the regulation of cerebral blood flow and/or systemic blood pressure. |
| Databáze: | OpenAIRE |
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