Effects of diuretics on stroke development in Kyoto–Wistar stroke-prone spontaneously hypertensive rats

1991 ◽  
Vol 81 (3) ◽  
pp. 335-340 ◽  
Author(s):  
John S. Smeda ◽  
Olexa Tkachenko
Keyword(s):  
Blood Pressure ◽  
Untreated Control ◽  
Spontaneously Hypertensive Rats ◽  
Haemorrhagic Stroke ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
High K ◽  
Blood Pressures ◽  
Low K

1. Previous studies have indicated that increases in dietary K+ promote diuresis and retard stroke development in stroke-prone spontaneously hypertensive rats (spSHR) fed a Japanese-style diet containing 4% NaCl. 2. It is possible that elevations in dietary K+ retard stroke development by inducing natriuresis and facilitating the clearance of Na+, and that diuretics associated with natriuresis might also be capable of retarding stroke development in spSHR. To test if this was the case, the onset of stroke development in spSHR fed a low (0.75%) K+ diet containing 4% NaCl (controls) was monitored and compared with that in spSHR treated with (a) frusemide, (b) chlorothiazide, (c) amiloride or (d) acetazolamide, and with (e) untreated spSHR fed a high (2.11%) K+ diet. 3. The onset of stroke, as well as death resulting from stroke, occurred at a significantly later age in spSHR fed a high K+ diet than in spSHR fed a low-K+ diet, despite the fact that both groups of spSHR rats had comparable blood pressures. 4. Treatment of spSHR with the above-named diuretics before stroke development did not alter the blood pressure of the rats. The onset of stroke development and death in spSHR treated with chlorothiazide, amiloride or acetazolamide was comparable with that observed in untreated control spSHR. In spSHR treated with frusemide, the onset of stroke was comparable with that of untreated control spSHR, whereas the onset of death after stroke development was accelerated. 5. Post mortems performed on spSHR that developed stroke indicated the presence of haemorrhagic stroke of comparable severity in the six groups of spSHR studied. 6. The results indicate that treatment of spSHR with diuretics at levels which do not alter the animals’ blood pressure does not alter the timing or incidence of stroke development, and does not prolong the lifespan of the animals after stroke has developed.

Relative Effectiveness of Chlorothiazide, Reserpine and Hydrallazine in Spontaneously Hypertensive Rats

1976 ◽  
Vol 51 (s3) ◽  
pp. 635s-637s
Author(s):  
E. D. Freis ◽  
D. O. Ragan
Keyword(s):  
Blood Pressure ◽  
Drinking Water ◽  
Untreated Control ◽  
Spontaneously Hypertensive Rats ◽  
Relative Effectiveness ◽  
Good Health ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Ether Anaesthesia ◽  
Blood Pressures

1. Previous studies in this laboratory indicated that a mixture of anti-hypertensive agents in the drinking water controlled the blood pressure of spontaneously hypertensive rats (SHR). The present study was designed to determine which of the agents exerted the greatest anti-hypertensive effect. 2. Treatment was begun at 12 weeks of age in groups of eleven to seventeen rats with one of the following drugs: reserpine, chlorothiazide or hydrallazine. Blood pressures were recorded by the tail method under light ether anaesthesia every 2 weeks until the rats were approximately 70 weeks of age. 3. At 50 weeks of age, blood pressure of chlorothiazaide-treated rats averaged 40 mmHg below untreated control SHR; reserpine-treated SHR were also 40 mmHg lower than control rats, and hydrallazine-treated SHR were 85 mmHg below the control rats. 4. Rats in all groups gained weight normally and appeared in good health. Although all drugs were active, hydrallazine was considerably more effective than chlorothiazide or reserpine in the SHR.

Na+, K+ and water balance in young spontaneously hypertensive rats: relationship to blood pressure after high K+ treatment

1987 ◽  
Vol 72 (3) ◽  
pp. 321-327 ◽  
Author(s):  
A. Louise Sugden ◽  
Barbara L. Bean ◽  
James A. Straw
Keyword(s):  
Blood Pressure ◽  
Water Balance ◽  
Spontaneously Hypertensive Rats ◽  
Urine Volume ◽  
Extracellular Fluid ◽  
Maximum Level ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
High K ◽  
Sufficient Magnitude

1. These studies were designed to investigate the effects of high dietary K+ on electrolyte and water balance in young spontaneously hypertensive rats (SHR) and to relate these effects to changes in blood pressure. 2. The high K+ diet reduced blood pressure by approximately 10 mmHg during the development of hypertension. Blood pressure, however, plateaued at the same maximum level as control by age 13 weeks. 3. Rats fed the high K+ diet showed a significant increase in water intake and urine volume throughout the treatment period but no change in plasma volume or extracellular fluid volume occurred. 4. A slight natriuresis was also observed in rats on the high K+ diet, but this was not of sufficient magnitude to decrease total body Na+. 5. These results confirm previous findings that K+ causes a diuresis and a natriuresis, but demonstrate that the diuretic action of K+ cannot explain its antihypertensive properties in young SHR.

High-potassium diet attenuates salt-induced acceleration of hypertension in SHR

1991 ◽  
Vol 260 (1) ◽  
pp. R21-R26 ◽  
Author(s):  
Y. Sato ◽  
K. Ando ◽  
E. Ogata ◽  
T. Fujita
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
High Potassium ◽  
Spontaneously Hypertensive ◽  
Antihypertensive Action ◽  
High K ◽  
Wistar Kyoto ◽  
Renal Vascular

We studied the effects of K supplementation (8% KCl) for 4 wk on blood pressure (BP), Na space, and renal hemodynamics in 5-wk-old, spontaneously hypertensive rats (SHR) or age-matched Wistar-Kyoto rats (WKY) eating normal-NaCl (0.66%) or high-NaCl (8%) diet. In WKY, high-Na and/or high-K diets had no effects on BP. In SHR, Na load accelerated the development of hypertension, whereas K supplementation did not affect BP of normal-Na SHR but attenuated the increase in BP with Na load. Correspondingly, Na load in SHR significantly increased renal vascular resistance (RVR), and K supplementation attenuated the increased RVR of Na-loaded SHR. Moreover, Na space of SHR was increased compared with that of WKY, and although Na load did not affect Na space, K supplementation tended to decrease Na space in SHR. These results indicate that 9-wk-old SHR is relatively volume-expanded compared with age-matched WKY, and K supplementation could improve the lowered slope of the pressure-Na excretion relationship in SHR, resulting in maintenance of Na balance. Thus the data suggest that changes in RVR, which might be intimately related to renal function for Na excretion, contribute to both salt sensitivity of SHR and antihypertensive action of K supplementation in Na-loaded SHR.

Cell Membrane Microviscosity and Ca2+-Mg2+-ATPase Activity do Not Contribute to Hypertension in the Spontaneously Hypertensive Rat Model

1993 ◽  
Vol 85 (5) ◽  
pp. 585-591 ◽  
Author(s):  
Robert I Norman ◽  
Navtej Achall
Keyword(s):  
Blood Pressure ◽  
Atpase Activity ◽  
Spontaneously Hypertensive Rats ◽  
Spontaneously Hypertensive Rat ◽  
Hypertensive Rats ◽  
Membrane Microviscosity ◽  
Spontaneously Hypertensive ◽  
Blood Pressures ◽  
Wistar Kyoto ◽  
Spontaneously Hypertensive Rat Model

1. The relationships between systolic blood pressure and altered erythrocyte Ca2+-Mg2+-ATPase activity and membrane microviscosity were assessed in membranes prepared from 20-week-old female Wistar-Kyoto normotensive and spontaneously hypertensive rats obtained from two different sources (Charles River and Harlan OLAC) and a second filial (F2) generation derived from a cross between Wistar-Kyoto rats and spontaneously hypertensive rats from one source (Charles River). 2. Spontaneously hypertensive rats from both sources had systolic blood pressures significantly higher than those of Wistar-Kyoto animals (P <0.05; 151 + 4 and 110 + 3 mmHg, Charles River; 155 + 4 and 122 + 4 mmHg, Harlan OLAC). The systolic blood pressures for the F2 rat population ranged between 73 and 168 mmHg. 3. Ca2+-Mg2+-ATPase activity was measured as ATP-dependent 45Ca2+ uptake into inside-out vesicles and microviscosity assessed by the measurement of polarization anisotropy of membrane incorporated fluorescent probes including 1,6-diphenyl-1,3,5-hexatriene, trimethylamino-1,6-diphenyl-1,3,5-hexatriene and a series of anthroyloxy fatty acids. 4. Contrary to previous studies, no relationship between adult systolic blood pressure and erythrocyte Ca2+-Mg2+-ATPase activity or general or localized membrane microviscosity was indicated by the comparison of spontaneously hypertensive and Wistar-Kyoto animals or in the analysis of the F2 rat population. 5. These results suggest that Ca2+-Mg2+-ATPase activity and membrane microviscosity are causally unrelated to hypertension in these animals. On the assumption that biophysical properties of the erythrocyte membrane reflect those of smooth muscle, our results suggest that membrane alteration does not play a significant role in the pathogenesis of hypertension in the spontaneously hypertensive rat model.

Voluntary exercise and its effects on young SHR and stroke-prone hypertensive rats

1986 ◽  
Vol 61 (1) ◽  
pp. 318-324 ◽  
Author(s):  
J. M. Overton ◽  
C. M. Tipton ◽  
R. D. Matthes ◽  
J. R. Leininger
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Activity Wheel ◽  
Voluntary Exercise ◽  
Hypertensive Rats ◽  
Voluntary Activity ◽  
Cerebrovascular Lesions ◽  
Spontaneously Hypertensive ◽  
Resting Blood Pressure ◽  
Blood Pressures

To determine whether voluntary exercise would lower resting blood pressure in spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SP-SHR), two separate but interrelated investigations were undertaken. The studies were initiated when the animals were 28–35 days of age and after they were assigned to either activity or sedentary cages. The activity cages were connected to transducers and recorders that allowed the monitoring and calculation of frequency, duration, and running speed. The SHR group ran 3–7 km/day intermittently for 12 wk at high speeds (48–68 m/min), which resulted in heart rates in excess of 500 beats/min. When the SHR exercised, they seldom exceeded 33 revolutions/bout (37 m) with the majority being less than 22 revolutions/bout. This type of exercise training significantly lowered, but did not normalize, resting blood pressure by approximately 20 mmHg [nontrained (NT) = 185 +/- 5; trained (T) = 163 +/- 5 mmHg] while increasing maximum O2 consumption (VO2max) (NT = 78 +/- 2.6; T = 95 +/- 2.2 ml X min-1 X kg-1) and endurance run time (NT = 62 +/- 9.0; T = 286 +/- 15.0 min), respectively. Although SP-SHR exhibited comparable patterns of voluntary activity, the effects were not similar. First, after approximately 5 wk of consuming a special Japanese rat chow and a 1% NaCl drinking solution, cerebrovascular lesions occurred and deaths ultimately resulted in both exercising and sedentary groups. Second, although there was statistical evidence for a training effect (higher VO2max, longer VO2 test run times), voluntary exercise had no advantage in either male or female runners in lowering resting blood pressures or in improving their life-spans. Whereas voluntary activity wheel exercise or moderate forced treadmill exercise will lower resting blood pressures in young SHR populations, similar generalizations cannot be made with young SP-SHR rats.

scholarly journals Proteomics Analysis of the Cerebellum in Spontaneously Hypertensive Rats Treated with Twirling Reinforcing Manipulation, Twirling Reducing Manipulation or Electroacupuncture

2020 ◽  
Author(s):  
Xu-dong Zhang ◽  
Xiao-min Hao ◽  
Jing-rong Liang ◽  
Jiao-juan Wu ◽  
Yan-jun Xue ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Control Group ◽  
Hypertensive Rats ◽  
Blank Control Group ◽  
Spontaneously Hypertensive ◽  
Parallel Reaction Monitoring ◽  
Differential Proteins ◽  
Blood Pressures ◽  
Electroacupuncture Treatment

Abstract Purpose: In this experiment, spontaneously hypertensive rats (SHR) were used to further explore the antihypertensive effect of acupuncture twirling reinforcing and reducing manipulation and the central effect mechanism of regulating blood pressure. Methods: 32 male SHR rats were randomly divided into 4 groups: twirling reinforcing manipulation group (RF), twirling reducing manipulation group (RD), electroacupuncture group (EA) (n = 8) and model group (M) (n = 8) and 8 WKY rats were used as blank control group (WKY). Group RD, RF and EA SHR took bilateral Taichong(LR3) point for acupuncture twirling method or electroacupuncture treatment, while WKY and M group did not use any acupuncture manipulation, but only carried out the same grasping and fixation. The differential proteins in cerebellum were screened by proteomic technology, and the key proteins and pathways involved in the pathogenesis of hypertension were selected.Results: RD, RF and EA lowered the blood pressures of the SHRs by varying degrees. The results of Parallel reaction monitoring(PRM) verification showed that among all the differential proteins, 13 differentially expressed proteins (DEPs) were selected for PRM verification. The KEGG annotations of differential proteins are involved in the regulation of lipolysis, autophagy, gap junction, phosphate inositol metabolism, splicing, lysosome, thermogenesis and RNA transport in adipocytes, etc. Conclusion: The results of the current study demonstrated that RD, RF and EA manipulations at the LR3 point reduced blood pressure and that RD was the most effective of the techniques used. Different acupuncture techniques have different pathways for screening and activating cerebellar differential proteins.

Sex and sex hormones influence the development of albuminuria and renal macrophage infiltration in spontaneously hypertensive rats

2007 ◽  
Vol 293 (4) ◽  
pp. R1573-R1579 ◽  
Author(s):  
Jennifer C. Sullivan ◽  
Laura Semprun-Prieto ◽  
Erika I. Boesen ◽  
David M. Pollock ◽  
Jennifer S. Pollock
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Sex Hormones ◽  
Spontaneously Hypertensive Rats ◽  
Macrophage Infiltration ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Blood Pressures ◽  
Over Time

There is a sex difference in hypertensive renal injury, with men experiencing greater severity and a more rapid progression of renal disease than women; however, the molecular mechanisms protecting against renal injury in women are unknown. The goal of this study was to determine whether sex hormones modulate blood pressure and the progression of albuminuria during the developmental phase of hypertension in male and female spontaneously hypertensive rats (SHR). Studies were also performed to examine how sex and sex hormones influence two major risk factors for albuminuria, overactivation of the renin-angiotensin system and oxidative stress. Blood pressure was measured by telemetry in gonad-intact and gonadectomized male and female SHR. Microalbumin excretion, measured over time, and macrophage infiltration were used to assess renal health. Male SHR had significantly higher blood pressures than female SHR, and gonadectomy decreased blood pressures in males with no effect in females. Male SHR displayed a gonad-sensitive increase in albuminuria over time, and female SHR had a gonad-sensitive suppression in macrophage infiltration. Female SHR had greater plasma ANG II levels and similar levels of renal cortical ANG II vs. levels shown in males but less AT1-receptor protein expression in the renal cortex. Female SHR also had a gonad-sensitive decrease in renal oxidative stress. Therefore, the renal protection afforded to female SHR is associated with lower blood pressure, decreased macrophage infiltration, and decreased levels of oxidative stress.

Effects of a high K+/low Na+ diet on blood pressure in young spontaneously hypertensive rats

1987 ◽  
Vol 72 (3) ◽  
pp. 313-319 ◽  
Author(s):  
A. Louise Sugden ◽  
James A. Straw ◽  
Barbara L. Bean
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Water Intake ◽  
Mechanism Of Action ◽  
Spontaneously Hypertensive Rats ◽  
Urine Volume ◽  
Plasma Renin ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
High K

1. Blood pressure was measured after treatment with a high K+, a low Na+ and a combined high K+/low Na+ diet in young spontaneously hypertensive rats (SHR). 2. A high K+ diet reduced blood pressure by approximately 10 mmHg during the development of hypertension. This decrease was accompanied by a significant increase in water intake and urine volume and a significant decrease in plasma renin activity (PRA). 3. A low Na+ diet also decreased blood pressure significantly, but, in contrast to the high K+ diet, water intake and urine volume significantly decreased and PRA increased. 4. When both diets were given together, the antihypertensive effects of both were eliminated. Thus while an increase in dietary K+ and a decrease in dietary Na+ are both effective antihypertensive regimens in SHR, the mechanism of action of each appears to be different and may be antagonistic in these animals.

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