Rho-kinase and the nitric oxide pathway modulate basilar arterial reactivity to acetylcholine and angiotensin II in streptozotocin-induced diabetic mice
| Autor: | Atsushi Miyamoto, Mitsuya Shiraishi, Md. Zahorul Islam, Cuong Van Dao |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Male medicine.medical_specialty Time Factors Pyridines medicine.medical_treatment Intraperitoneal injection Cerebral arteries Blood Pressure 030204 cardiovascular system & hematology Nitric Oxide Streptozocin Nitric oxide Diabetes Mellitus Experimental 03 medical and health sciences chemistry.chemical_compound Mice 0302 clinical medicine Internal medicine Diabetes mellitus Renin–angiotensin system medicine Animals Pharmacology Mice Inbred ICR rho-Associated Kinases business.industry Angiotensin II General Medicine Streptozotocin medicine.disease Amides Acetylcholine 030104 developmental biology Blood pressure Endocrinology NG-Nitroarginine Methyl Ester chemistry Cardiovascular Diseases business medicine.drug |
| Zdroj: | Naunyn-Schmiedeberg's archives of pharmacology. 390(9) |
| ISSN: | 1432-1912 |
| Popis: | Diabetes mellitus comprises a heterogeneous group of metabolic disorders with underlying hyperglycemia and secondary cardiovascular complications. Growing evidence suggests that vascular dysfunction is among the most important causes of diabetic cardiovascular disease. Therefore, we determined whether streptozotocin (STZ)-induced diabetes in mice affects blood pressure and cerebral arterial responsiveness to angiotensin (Ang) II and acetylcholine (ACh), which are important modulators of cerebrovascular autoregulation. Diabetes was induced using a single intraperitoneal injection of STZ (50 mg/kg). Blood pressure was measured in conscious mice using the indirect tail-cuff method. Functional studies of the isolated arteries’ response to vasoactive substances were performed using a micro-organ-bath system at 60 days after STZ injection. Systolic, diastolic, and mean blood pressures significantly increased at days 45 and 60 in the STZ-induced diabetic mice. In the isolated basilar arteries, ACh-induced relaxation, which is dependent on nitric oxide (NO) production from endothelial cells, decreased. In contrast, Ang II-induced contraction, mediated via rho-kinase activation in the smooth muscle, increased in the diabetic mice. There was significantly greater relaxation in the precontracted isolated basilar arteries of diabetic mice that had been treated with Y27632, a rho-kinase inhibitor, than in the control mice arteries. Pretreatment with Nω-nitro-l-arginine (L-NAME), an NO synthase inhibitor, significantly enhanced Ang II-induced contraction and Y27632-induced relaxation in the control basilar arteries but not in the STZ-induced diabetic mice arteries. These results suggest that decreased NO bioavailability and enhanced rho-kinase activity in basilar arteries contribute to altered reactivity to ACh and Ang II, respectively, in STZ-induced diabetic mice. |
| Databáze: | OpenAIRE |
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