Decreased density of endothelin-1 binding sites in aortic smooth muscle cells of spontaneously hypertensive rats

1991 ◽  
Vol 9 (6) ◽  
pp. S192 ◽  
Author(s):  
Lucia Zanin ◽  
GianPaolo Rossi ◽  
Paolo Pauletto ◽  
Marta Tonello ◽  
Gabriella Cargnelli ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Binding Sites ◽  
Spontaneously Hypertensive Rats ◽  
Muscle Cells ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Endothelin 1

Incidence of multinucleated and polyploid aortic smooth muscle cells cultured from different age groups of spontaneously hypertensive rats

1992 ◽  
Vol 70 (11) ◽  
pp. 1496-1501 ◽  
Author(s):  
Robert M. K. W. Lee ◽  
Roop B. Conyers ◽  
Chiu-Yin Kwan
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Spontaneously Hypertensive Rats ◽  
Age Groups ◽  
Muscle Cells ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Aortic Smooth Muscle Cells ◽  
Positive Correlation ◽  
Aortic Smooth Muscle

Cell size and incidence of multinucleated, polyploid cells in cultured aortic smooth muscle cells from different age groups of spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto rats (WKY) were compared. Smooth muscle cells from SHR were generally larger than those from WKY, and the percentage of multinucleated smooth muscle cells was always higher in SHR than WKY in the three age groups of rats studied (3–4, 10–12, and 28–30 weeks). In smooth muscle cells from the 3- to 4-week group, there was a positive correlation between cell diameter and the percentage of multinucleated smooth muscle cells. Microdensitometric measurements also showed that the incidence of polyploid smooth muscle cells was always higher in SHR than WKY in the three age groups. There was a positive correlation between DNA density and nuclear area measurements in all the age groups of SHR and WKY. We conclude that cultured aortic smooth muscle cells from different age groups of SHR and WKY contained heterogeneous populations of cells and that, under our culture conditions, the polyploidy of the smooth muscle cells found in vivo was maintained in the SHR and WKY.Key words: hypertension, cultured smooth muscle cells, aorta, polyploidy.

Changes of β-adrenoceptors in the aortic muscle cells of spontaneously hypertensive rats

1990 ◽  
Vol 68 (11) ◽  
pp. 1461-1468 ◽  
Author(s):  
C. Y. Kwan ◽  
R. M. K. W. Lee
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Spontaneously Hypertensive Rats ◽  
Muscle Cells ◽  
Hypertensive Rats ◽  
Intact Cells ◽  
Spontaneously Hypertensive ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle

The characteristics of [125I]monoiodocyanopindolol (ICYP) binding to β-adrenoceptors of cultured aortic smooth muscle cells derived from 4-week-old spontaneously hypertensive rats (SHR) and the Wistar–Kyoto normotensive rats (WKY) were examined. During optimization of the binding assays, we found that the specific binding of ICYP by intact cells was masked by a high level of nonspecific ICYP accumulation in intact cells presumably owing to the lipophilic nature of ICYP. Optimal specific ICYP binding requires that the cells be gently lysed with hypotonic dilution followed by a freeze-and-thaw cycle. Under most experimental conditions tested, the total number of ICYP binding sites in WKY aortic muscle cells was considerably and consistently smaller than that in SHR cells. There was no difference in the Kd values for ICYP binding to SHR and WKY cells. However, when ICYP binding was carried out using crude membrane fractions with well-defined plasma-membrane content isolated from aortic muscle strips of adult rats, we found no difference in the number of β-adrenoceptor sites between SHR and WKY. Morphological evidence indicated that cultured SHR aortic muscle cells contained a greater proportion of larger cells with multinuclear features. These results suggest that an increase in the number of β-adrenoceptor density per cell in SHR may be associated with cellular hypertrophy of aortic smooth muscle cells. We conclude that under cultured conditions, a higher incidence of polyploid smooth muscle cells in the SHR as compared with WKY was expressed earlier than under in vivo conditions. Therefore, the interpretation of results obtained from cultured cell studies in relation to under in vivo conditions should be exercised with caution.Key words: β-adrenoceptor, vascular smooth muscle, aorta, cell membranes, hypertension, hypertrophy.

ETB receptors on aortic smooth muscle cells of spontaneously hypertensive rats

1993 ◽  
Vol 264 (2) ◽  
pp. C479-C484 ◽  
Author(s):  
V. K. Batra ◽  
J. R. McNeill ◽  
Y. Xu ◽  
T. W. Wilson ◽  
V. Gopalakrishnan
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Spontaneously Hypertensive Rats ◽  
Muscle Cells ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Subtype B ◽  
Sd Rats

The effect of the agonist sarafotoxin 6c (S6c), selective for endothelin (ET) receptor subtype B (ETB), on cytosolic free Ca2+ concentrations ([Ca2+]i) was determined by fura-2 methodology using aortic smooth muscle cells (ASMC) isolated from spontaneously hypertensive rats (SHR) and two normotensive strains, Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. The basal [Ca2+]i was significantly higher in the ASMC of SHR (139 +/- 8 nM) than WKY (107 +/- 7 nM) and SD (102 +/- 4 nM) rats. S6c produced concentration-dependent elevations in [Ca2+]i in the ASMC of WKY and SHR, whereas it did not evoke significant increases in the [Ca2+]i levels in the ASMC of SD rats. The peak [Ca2+]i levels observed with maximal concentrations of S6c (500 nM) was higher (P< 0.01) in the SHR (346 +/- 36 nM) than the WKY group (148 +/- 19 nM). The natural nonselective agonist, ET-1, evoked maximal [Ca2+]i in the ASMC of SHR, WKY, and SD rats of 635 +/- 43, 304 +/- 19, and 289 +/- 24 nM, respectively. Depletion of extracellular Ca2+ concentration led to the reduction of the peak [Ca2+]i response to ET-1 by 60 and 40% in the WKY and SHR cells, respectively, whereas the response to S6c remained unaffected. The ETA-selective antagonist, BQ-123 (1 microM), did not affect the [Ca2+]i response to S6c, whereas it attenuated the response to ET-1 by 90 and 70% in the WKY and SHR cells, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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