Adrenergic activity in arteries of spontaneously hypertensive rats

1981 ◽  
Vol 59 (10) ◽  
pp. 1104-1107 ◽  
Author(s):  
Thomas T. Zsotér ◽  
Steve Sirko ◽  
Camille Wolchinsky ◽  
Dezso Kadar ◽  
Laszlo Endrenyi
Keyword(s):  
Column Chromatography ◽  
Spontaneously Hypertensive Rats ◽  
Similar Proportion ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Tail Artery ◽  
Wistar Kyoto Rats ◽  
Adrenergic Activity ◽  
Wistar Kyoto ◽  
Uptake And Release

This study compares the uptake and release of [3H]norepinephrine and residual 3H content in the tail artery of 7- to 9-week-old and 16- to 18-week-old spontaneously hypertensive rats (SHR) and age matched normotensive Wistar Kyoto rats (WKR). The composition of the 3H overflow from the artery, analyzed with column chromatography, revealed similar proportion of norepinephrine and in metabolites, namely normetanephrine, O-methylated deaminated products, dihydroxy-phenylglycol, and dihydroxymandelic acid in SHR and WKR. [3H]Norepinephrine was retained however in greater proportion in vessels of young and older SHR than in WKR.

Contribution of Vascular Nitric Oxide to Basal Blood Pressure in Conscious Spontaneously Hypertensive Rats and Normotensive Wistar Kyoto Rats

1995 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Naoyoshi Minami ◽  
Yutaka Imai ◽  
Jun-Ichiro Hashimoto ◽  
Keishi Abe
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Methyl Ester ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Basal Blood Pressure ◽  
Wistar Kyoto

1. The aim of this study was to clarify the extent to which vascular nitric oxide contributes to basal blood pressure in conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. 2. The contribution of vascular nitric oxide to maintenance of blood pressure was estimated by measuring the pressor response to an intravenous injection of nitric oxide synthase inhibitor, Nω-l-arginine methyl ester, given after serial injections of captopril, vasopressin V1-receptor antagonist (V1-antagonist) and ganglion blocker (pentolinium) in conscious spontaneously hypertensive and Wistar Kyoto rats aged 20–28 weeks. To estimate the ‘amplifier property’ of hypertrophied vasculature in spontaneously hypertensive rats, which is known to modulate pressor responses, the lower blood pressure plateau after serial injections of captopril, V1-antagonist and pentolinium and the maximum blood pressure elicited by subsequent injection of increasing doses of phenylephrine were also measured. 3. The serial injections of captopril, V1-antagonist and pentolinium decreased mean arterial pressure from 164 ± 9 mmHg to 67 ± 2 mmHg and from 117 ± 2 mmHg to 49 ± 1 mmHg in spontaneously hypertensive and Wistar Kyoto rats respectively. The subsequent injection of Nω-l-arginine methyl ester restored mean arterial pressure almost to its control levels in both spontaneously hypertensive and Wistar Kyoto rats. The absolute changes in mean arterial pressure elicited by Nω-l-arginine methyl ester were significantly greater in spontaneously hypertensive than in Wistar Kyoto rats (P < 0.01), but there was no significant difference in the responses to Nω-l-arginine methyl ester when they were expressed as percentages of either the lower blood pressure plateau or maximum blood pressure. 4. These results indicate that basal blood pressure in both spontaneous hypertensive and Wistar Kyoto rats is maintained by a balance between vascular nitric oxide and major pressor systems. They also suggest that the vasodilatory effect of vascular nitric oxide does not differ between spontaneously hypertensive and Wistar Kyoto rats, and that the increased pressor effect of Nω-l-arginine methyl ester in spontaneously hypertensive rats is due to a vascular amplifier mechanism.

Calmodulin levels in hypertensive rats

1985 ◽  
Vol 68 (4) ◽  
pp. 407-410 ◽  
Author(s):  
J. Higaki ◽  
T. Ogihara ◽  
Y. Kumahara ◽  
E. L. Bravo
Keyword(s):  
Intracellular Calcium ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Deoxycorticosterone Acetate ◽  
Spontaneously Hypertensive ◽  
Calcium Dependent ◽  
Wistar Kyoto Rats ◽  
Regulatory Systems ◽  
Wistar Kyoto ◽  
The Brain

1. Intracellular calmodulin levels were measured by direct radioimmunoassay in spontaneously hypertensive rats (SHR) and Wistar—Kyoto rats (WKY). 2. Decreased calmodulin levels were demonstrated in the brain, heart, aorta and kidney of spontaneously hypertensive rats compared with those in Wistar—Kyoto rats. 3. Calmodulin levels in the brain were also decreased in deoxycorticosterone acetate (DOCA)-salt rats, but not changed significantly in the heart, aorta and kidney compared with those in Wistar—Kyoto rats. 4. These findings suggest that intracellular calcium-dependent regulatory systems are genetically disrupted in spontaneously hypertensive rats, but this is probably not an important factor in the development of hypertension.

Distensibility of the Left Atrial Wall in Spontaneously Hypertensive Rats Compared with That in Normotensive Wistar-Kyoto Rats

1980 ◽  
Vol 59 (s6) ◽  
pp. 361s-363s
Author(s):  
S.-E. Ricksten ◽  
T. Yao ◽  
B. Ljung ◽  
P. Thorean
Keyword(s):  
Left Atrial ◽  
Spontaneously Hypertensive Rats ◽  
Relative Length ◽  
Hypertensive Rats ◽  
Atrial Wall ◽  
Cross Sectional ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Left Atrial Wall ◽  
Wistar Kyoto

1. The cardiac mechanoreceptors, which in rats are mainly located in the left atrial wall, are reset in spontaneously hypertensive rats. The atrial pressure has to be almost twice as high in spontaneously hypertensive rats as in normotensive controls to produce similar receptor activations, as is apparent from previous studies. 2. The present study was performed to investigate whether this resetting is due to decreased distensibility of left atrial walls in the spontaneously hypertensive rats. 3. Static load-length relationships were investigated in vitro on left atrial strips, and pressure-volume relationships were studied on isolated left atria from spontaneously hypertensive and normotensive Wistar-Kyoto rats. 4. The force per cross-sectional area exerted during a relative length increase of 80% was significantly greater in spontaneously hypertensive rats. The dynamic but not the static distensibility was significantly lower in these animals. 5. The decreased dynamic distensibility of left atrial walls in spontaneously hypertensive rats can at least partly explain the resetting of atrial receptor function.

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