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Characterization of the endothelin receptor in primary cultures of human aortic smooth muscle cells.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Yazawa, Hidenori Iida-Kubota, E. Honma, Yusuke Honda, Kenji |
| Copyright Year | 1993 |
| Abstract | We characterized the endothelin receptor subtypes in primary cultures of human aortic smooth muscle cells (HASMCs) by binding studies. [125I]-Endothelin (ET)-1 saturation experiments showed the existence of a homogeneous population of binding sites with the high affinity (KD value) of 97 +/- 37 pM and maximum number of binding sites (Bmax) of 54 +/- 10 fmol/mg protein. However, almost no specific [125I]-ET-3 binding was observed. Inhibition of [125I]-ET-1 binding in the HASMCs membrane by nonlabeled compounds showed the following order of effectiveness: ET-1 = ET-2 = FR139317 >> ET-3. These results suggest that the endothelin receptor of HASMCs is of the ETA type. We also studied the effect of ET-1 on the cytosolic [Ca2+]i in HASMCs loaded with fura-2/AM. In 1.3 mM Ca2+, ET-1 produced a dose-dependent, biphasic increase in signal with a maximal effect at 10 nM. At this concentration, ET-1 produced a transient increase in [Ca2+]i that reached a peak at 1 min, which was followed by a slow but sustained increase in [Ca2+]i. This second phase was attenuated in Ca(2+)-deficient medium. Furthermore, ET-1 increased inositol 1,4,5-triphosphate in a time- and dose-dependent manner. These results suggest that the endothelin receptors of HASMCs are of the ETA type, which couple with Ca2+ channels. |
| Starting Page | 7168 |
| Ending Page | 7171 |
| Page Count | 4 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.jstage.jst.go.jp/article/jphs1951/63/3/63_3_313/_pdf |
| PubMed reference number | 8107324v1 |
| Volume Number | 63 |
| Issue Number | 3 |
| Journal | Japanese journal of pharmacology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Affinity Binding Sites Calcium ion Endothelin Receptor Femtomole Inositol 1,4,5-Trisphosphate Muscle Cells Myocytes, Smooth Muscle Smooth muscle (tissue) Subtype (attribute) Tissue membrane |
| Content Type | Text |
| Resource Type | Article |
