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Effect of Inhibition of Sarcoplasmic $Ca^{2+}$-ATPase on Vasoconstriotion and Cytosolic $Ca^{2+}$in Aortic Smooth Muscle from Spontaneously Hypertensive and Normotensive Rats
| Content Provider | Scilit |
|---|---|
| Author | Tepel, M. Ruess, C. Mehring, N. Neusser, M. Zidek, W. |
| Copyright Year | 1994 |
| Description | To evaluate the influence of the sarcoplasmic $Ca^{2+}$ -ATPase, isometric vaso-constrictions of aortic strips from spontaneously hypertensive rats from the Münster strain (SHR) and normotensive Wistar-Kyoto rats (WKY) were measured after inhibition of $Ca^{2+}$-ATPase by thapsigargin. Inhibition of $Ca^{2+}$ -ATPase by thapsigargin caused a biphasic contractile response of the aorta in both SHR and WKY (maximum increase of tension: 1.7 ± 0.3 $x10^{−3}$ Newton and 2.1 ± 0.3 $x10^{-3}$ Newton, respectively; mean ± SE). The second peak of the contractile response was abolished in the absence of external calcium or by infebition of transplasmamembrane calcium influx by nifedipine, indicating that the second peak occurs as a consequence of calcium influx from the extracellular space. The initial peak of the contractile response after thapsigargin administration was abolished in the presence of an intracellular calcium antagonist, 8-(diethylamino-)-octyl-3,4,5-trimethoxy-benzoate (TMB-8), indicating that the initial response was due to calcium release from intracellular stores. Measurements using the fluorescent dye fura2 showed that thapsigargin increased the cytosolic free calcium concentration ([Ca^{2+}$]_{i}$) in SHR by 72.6 ± 7.3 nmol/1 (n=34) and in WKY by 53.3 ± 6.6 nmol/1 (n=39), showing no significant differences between the two strains. The inhibition of $Ca^{2+}$ -ATPase increases [Ca^{2+}$]_{i}$ and causes vasoconstriction. The vasoconstriction produced by thapsigargin is not significantly different between SHR and WKY. |
| Related Links | https://www.tandfonline.com/doi/pdf/10.3109/10641969409067958 |
| Ending Page | 506 |
| Page Count | 14 |
| Starting Page | 493 |
| ISSN | 10641963 |
| e-ISSN | 15256006 |
| DOI | 10.3109/10641969409067958 |
| Journal | Clinical and Experimental Hypertension |
| Issue Number | 4 |
| Volume Number | 16 |
| Language | English |
| Publisher | Informa UK Limited |
| Publisher Date | 1994-01-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Clinical and Experimental Hypertension Peripheral Vascular Disease Ca2+ -atpase Thapsigargin Vasoconstriction Primary Hypertension |
| Content Type | Text |
| Resource Type | Article |
| Subject | Physiology Internal Medicine |
