Lack of increase in platelet Ca2+ and Na+ in deoxycorticosterone acetate-salt hypertensive rats
| Autor: | Ryoji Ozono, Tetsuya Oshima, Hideo Matsuura, Mari Ishida, G. Kajiyama, Tomoko Ishida |
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| Rok vydání: | 1994 |
| Předmět: |
Blood Platelets
Male medicine.medical_specialty Physiology Salt (chemistry) Blood Pressure In Vitro Techniques chemistry.chemical_compound Cytosol Thrombin Ethers Cyclic Heart Rate Reference Values Physiology (medical) Internal medicine medicine Animals Platelet Rats Wistar Desoxycorticosterone Benzofurans Fluorescent Dyes chemistry.chemical_classification Body Weight Sodium Sodium Dietary Metabolism Rats Endocrinology chemistry Hypertension Ionomycin Calcium Deoxycorticosterone acetate Intracellular medicine.drug |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 267:R1288-R1293 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | We have previously characterized abnormal Ca2+ handling in platelets of spontaneously hypertensive rats (SHRs). In this study, we investigated whether cellular Ca2+ metabolism and/or Na+ concentration is altered in platelets of deoxycorticosterone acetate-salt hypertensive rats (DOCA rats). The resting cytosolic Ca2+ concentration ([Ca2+]i) in platelets was significantly lower in DOCA rats than controls (54.5 +/- 1.4 vs. 61.2 +/- 2.3 nmol/l). The amplitude of the [Ca2+]i transient induced by thrombin was significantly increased in the absence, but not the presence, of external Ca2+ in DOCA rats compared with control rats. The [Ca2+]i response to 5 mumol/l ionomycin in the Ca(2+)-free buffer was greater in DOCA rats than in controls (546 +/- 23 vs. 470 +/- 18 nmol/l), indicating larger intracellular Ca2+ stores. The rate of recovery of [Ca2+]i after the peak response to thrombin was decreased in DOCA rats (79% at 0.1 U/ml and 91% at 1.0 U/ml thrombin of control rats). Cytosolic Na+ concentration ([Na+]i) in platelets was similar in DOCA and control rats. Altered Ca2+ levels are not correlated with [Na+]i in this salt-sensitive hypertensive model. Therefore, an increased [Ca2+]i is not an obligatory phenomenon in hypertension. |
| Databáze: | OpenAIRE |
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