Comparison of Contractile Responses Relative to Protein between Isolated Diabetic and Non-diabetic Rat Aortae to KCl and a-Adrenoceptor Agonists in Different Extracellular Calcium Concentrations
| Autor: | Junko Nakasone, Satoshi Yamashiro, Matao Sakanashi, Tatsushi Itomine, Toshihiro Matsuzaki, Makie Higuchi, Kanako Miyagi, Mayuko Sakanashi, Katsuhiko Noguchi |
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| Rok vydání: | 2011 |
| Předmět: |
Male
Agonist medicine.medical_specialty medicine.drug_class Muscle Proteins chemistry.chemical_element Aorta Thoracic In Vitro Techniques Calcium Clonidine Muscle Smooth Vascular Methoxamine Diabetes Mellitus Experimental Potassium Chloride Rats Sprague-Dawley Norepinephrine Internal medicine Drug Discovery Prazosin Extracellular Animals Medicine business.industry Streptozotocin Rats Yohimbine Endocrinology chemistry cardiovascular system medicine.symptom business Adrenergic alpha-Agonists Vasoconstriction Muscle Contraction medicine.drug |
| Zdroj: | Arzneimittelforschung. 50:1078-1083 |
| ISSN: | 1616-7066 0004-4172 |
| DOI: | 10.1055/s-0031-1300344 |
| Popis: | The influence of extracellular Ca 2+ concentration on contractile responses of aortae isolated from diabetic rats to KCl and α-adrenoceptor agonists was compared with that of non-diabetic rat aortae. Diabetic rats 6 weeks after administration of streptozotocin showed significantly lower body weight and higher plasma glucose concentration, but the protein content per each aortic ring preparation was not significantly different from that of non-diabetic preparation. Both diabetic and non-diabetic aortae showed concentration-dependent contractile responses to norepinephrine, which were concentration-dependently inhibited by prazosin. On the other hand, Clonidine induced small contractions in both aortae, which tended to be more inhibited by prazosin than yohimbine. In non-diabetic aortae, the contractile responses to KCl, norepinephrine, methoxamine and Clonidine were significantly greater with 2.5 mmol/l of extracellular Ca 2+ than 1.25 mmol/l. In diabetic aortae, however, the contractile responses were not significantly influenced by changes in extracellular Ca 2+ concentration. Additionally, the contractile responses to each agonist were markedly greater in non-diabetic aortae than diabetic ones. The present results indicate that the contractions of diabetic vasculature do not respond to changes in extracellular Ca 2+ concentration, suggesting that there may be some impairment of Ca 2+ related mechanisms. |
| Databáze: | OpenAIRE |
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