Comparison of sarcoplasmic reticulum characteristics in aortic smooth and ventricular muscles using chemically skinned preparations
| Autor: | A. O. Grassi de Gende, Ernesto A. Aiello |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Male
Ruthenium red medicine.medical_specialty Heart Ventricles chemistry.chemical_element In Vitro Techniques Calcium Muscle Smooth Vascular chemistry.chemical_compound Internal medicine medicine Animals Rats Wistar Aorta Ion transporter Ryanodine receptor Endoplasmic reticulum Histological Techniques Cardiac muscle Biological Transport General Medicine Rats Sarcoplasmic Reticulum medicine.anatomical_structure Endocrinology chemistry Circulatory system cardiovascular system Liberation |
| Zdroj: | Archives Internationales de Physiologie, de Biochimie et de Biophysique. 101:17-20 |
| ISSN: | 0778-3124 |
| DOI: | 10.3109/13813459308998123 |
| Popis: | The active Ca2+ transport and the kinetics of Ca2+ efflux in sarcoplasmic reticulum (SR) of skinned aortic smooth muscle cells are compared with those in SR of skinned ventricular muscle cells. 45Ca uptake was measured at pCa 6.6 in the presence of 10 mM of K oxalate from 2 to 30 min. Unstimulated and Ca2+ stimulated Ca2+ efflux were assessed on Ca2+ desaturation curves performed in skinned cells preloaded with 45Ca in the absence of K oxalate. Results demonstrate that SR in aortic smooth muscle cells compared with SR in ventricular cells has: a) 2 times lower initial phase of Ca2+ uptake, b) 10 times lower enclosed volume, c) higher rate of unstimulated Ca2+ efflux and d) higher plus more sustained release of Ca2+ induced by Ca2+. It is also proved that the stimulated release of Ca2+ can be suppressed by 0.6 mM of ryanodine in aortic smooth muscle and by 50 microM of ruthenium red in ventricular muscle. This work provides direct measurements of Ca2+ transport capacity and of Ca2+ release of in situ sarcoplasmic reticulum. It quantifies the functional differences between vascular smooth and ventricular muscles. |
| Databáze: | OpenAIRE |
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