The role of .ALPHA.1- and .ALPHA.2-adrenoceptors in canine systemic capacitance vessels. A study with measurement of mean circulatory pressure
| Autor: | Isao Hirose, Kuniyuki Takai, Senri Hirakawa, Hisayasu Wada, Teruchika Sahashi, Hiroyasu Ito, Kijun Nagata |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Pentobarbital Physiology Blood Pressure Phenylephrine Dogs α2 adrenoceptor Heart Rate Internal medicine medicine Prazosin Animals Cardiac Output business.industry Yohimbine Azepines Receptors Adrenergic alpha Endocrinology Mean blood pressure Epinephrine Anesthesia Circulatory system Vascular Resistance Cardiology and Cardiovascular Medicine business Adrenergic alpha-Agonists medicine.drug |
| Zdroj: | Japanese Circulation Journal. 54:152-160 |
| ISSN: | 1347-4839 0047-1828 |
| DOI: | 10.1253/jcj.54.152 |
| Popis: | We investigated the presence of alpha-adrenoceptor subtypes in systemic capacitance vessels by examining the effects of alpha 1- and alpha 2-agonists or antagonists on the mean circulatory pressure (MCP). Dogs were anesthetized with pentobarbital, and after total spinal anesthesia, epinephrine was given intravenously to maintain mean blood pressure at about 80 mmHg. 1. With intravenous injection of phenylephrine (alpha 1-agonist, 10 micrograms/kg, n = 7), and of BHT 920 (alpha 2-agonist, 5 micrograms/kg, n = 7), MCP increased significantly from 9.8 +/- 0.4 (mean +/- SE) to 10.9 +/- 0.3 mmHg (+11.2%, p less than 0.01), and from 9.3 +/- 0.4 to 10.3 +/- 0.4 mmHg (+10.8%, p less than 0.05), respectively. 2. Intravenous injection of prazosin (alpha 1-antagonist, 150 micrograms/kg, n = 7) and of yohimbine (alpha 2-antagonist, 30 micrograms/kg, n = 7) decreased MCP significantly from 9.9 +/- 0.4 to 8.2 +/- 0.5 mmHg (-17.2%, p less than 0.01), and from 9.8 +/- 0.2 to 7.6 +/- 0.3 mmHg (-22.4%, p less than 0.01), respectively. 3. Intravenous injection of phenylephrine (10 micrograms/kg, n = 7) after pretreatment with prazosin (150 micrograms/kg) decreased MCP significantly from 9.5 +/- 0.3 to 7.8 +/- 0.3 mmHg (-17.9%, p less than 0.01). MCP decreased significantly from 9.9 +/- 0.3 to 8.2 +/- 0.3 mmHg (-17.2%, p less than 0.01) after intravenous injection of BHT 920 (5 micrograms/kg, n = 7) following pretreatment with yohimbine (30 micrograms/kg).(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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