Calcium Accumulation and Calcium Binding by the Cell Membranes of Cardiomyocytes and Smooth Muscle of Aorta in Spontaneously Hypertensive Rats

1980 ◽  
Vol 59 (s6) ◽  
pp. 207s-209s ◽  
Author(s):  
S. N. Orlov ◽  
Yu. V. Postnov

1. The ability of isolated membrane fractions of cardiomyocytes, aortic smooth muscle and erythrocytes from spontaneously hypertensive rats to bind calcium was investigated isotopically. 2. Plasma membranes of aortic smooth muscle and erythrocytes of spontaneously hypertensive rats possess a lower calcium-binding ability than preparations from normotensive controls. 3. Sarcoplasmic reticulum from the myocardium of spontaneously hypertensive rats had a lower ability to accumulate calcium. 4. Changes in the calcium-binding ability of the erythrocyte membrane of spontaneously hypertensive rats was related to the diminution of the amount of exchangeable calcium on the inner part of the membrane. The latter may be the cause of the increase of erythrocyte membrane permeability for sodium in spontaneously hypertensive rats and in patients with essential hypertension.




1992 ◽  
Vol 70 (11) ◽  
pp. 1496-1501 ◽  
Author(s):  
Robert M. K. W. Lee ◽  
Roop B. Conyers ◽  
Chiu-Yin Kwan

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.





1982 ◽  
Vol 63 (s8) ◽  
pp. 37s-39s ◽  
Author(s):  
P. Marche ◽  
S. Koutouzov ◽  
P. Meyer

1. The distribution and metabolism of inositol phospholipids were studied in the erythrocyte membrane of spontaneously hypertensive and normotensive Wistar-Kyoto rats. The incorporation of 32P into these lipids was considered as an index of their turnover, and a reflection of their metabolism. 2. With [γ-32P]ATP as the source of label only the polyphosphoinositides (diphosphoinositide and triphosphoinositide) incorporated 32P. The levels of labelling were lower in hypertensive than in normotensive rats. Our data indicate that, in the hypertensive rats, the kinases responsible for the labelling of polyphosphoinositides exhibited decreased Vmax. for ATP. 3. These changes may be related to those described for calcium binding and transport in the erythrocyte of spontaneously hypertensive rats.



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