The responses of carotid vascular strips from spontaneously hypertensive and normotensive rats

1980 ◽  
Vol 58 (1) ◽  
pp. 53-59 ◽  
Author(s):  
V. C. Swamy ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Spontaneously Hypertensive Rats ◽  
Carotid Arteries ◽  
Age Groups ◽  
Extracellular Calcium ◽  
Induced Responses ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Vascular Responses ◽  
Carotid Arterial

The responses to noradrenaline (NA) and KCl of carotid arterial strips from spontaneously hypertensive rats (SHR) and three strains of normotensive rats (NR) were compared using tissues obtained from young (5–7 weeks) or older (15–17 weeks) rats. The maximum responses and sensitivity of strips from SHR were less than those of NR in both age groups. Relaxation of maximum NA-induced responses was consistently faster, and relaxation of KCl-induced responses generally slower with strips from SHR. Carotid strips from young SHR showed a greater dependence on extracellular calcium in their responses to NA and a lesser dependence in their KCl-induced responses than tissues from NR. We conclude that the smooth muscle of carotid arteries from SHR differs intrinsically from that of NR and that the differences in vascular responses may be related to altered excitation-contraction processes in the SHR.

Inhibition by cinnarizine of the responses of smooth muscle from spontaneously hypertensive and normotensive rats

1983 ◽  
Vol 61 (12) ◽  
pp. 1523-1525 ◽  
Author(s):  
C. Nghiem ◽  
V. C. Swamy ◽  
D. J. Triggle
Keyword(s):  
Smooth Muscle ◽  
Calcium Antagonist ◽  
Spontaneously Hypertensive Rats ◽  
Carotid Arteries ◽  
Induced Responses ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Tissue Responses ◽  
Wistar Kyoto ◽  
Carotid Arterial

A comparison was made of the inhibition by cinnarizine, a calcium antagonist, of the contractile responses of aortic, carotid, and iliac arterial strips and vasa deferentia from 15- to 17-week-old spontaneously hypertensive rats (SHR) and their normotensive counterparts, Wistar Kyoto (WKY) rats. KCl-induced responses of the aorta from both strains of rats and carotid arteries from WKY only were more sensitive to inhibition than were responses to norepinephrine. No significant differences were observed in the inhibition of tissue responses from the two strains of rats with the exception of the K+-induced responses of carotid arterial strips from SHR which were significantly less sensitive to inhibition when compared with carotid strips from WKY.

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.

Calcium reactivity and antagonism in portal veins from spontaneously hypertensive and normotensive rats

1984 ◽  
Vol 62 (1) ◽  
pp. 146-150 ◽  
Author(s):  
A. L. Harris ◽  
V. C. Swamy ◽  
D. J. Triggle
Keyword(s):  
Inhibitory Activity ◽  
Spontaneously Hypertensive Rats ◽  
Age Groups ◽  
Induced Responses ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Activity Frequency ◽  
Blood Pressures ◽  
Portal Veins ◽  
Wistar Kyoto

Reactivities of portal veins from spontaneously hypertensive rats (SHR) and normotensive controls (Wistar Kyoto, WKY) at 5–7 and 15–17 weeks of age were compared. Systolic blood pressures were not different at 5–7 weeks but those of SHR were significantly elevated (177 ± 4 mmHg) (1 mmHg = 133.322 Pa) at 15–17 weeks. Spontaneous activity, frequency, and tension were greater in SHR for both age groups. Young SHR were more sensitive to K+ at 5–7 weeks but less sensitive at 15–17 weeks than age-matched WKY rats. Sensitivity to Ca2+ in a K+-depolarizing medium was higher in SHR than in WKY for both age groups. Maximum tension responses to K+ or Ca2+ were greater in SHR. The Ca2+ channel antagonists nifedipine, nitrendipine, and nisoldipine were potent inhibitors of both noradrenaline- and K+-induced responses but did not show differences in inhibitory activity between WKY and SHR.

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