Changes in the activity and expression of protein phosphatase-1 accompany the differential regulation of NHE3 before and after the onset of hypertension in spontaneously hypertensive rats

2014 ◽  
Vol 211 (2) ◽  
pp. 395-408 ◽  
Author(s):  
R. O. Crajoinas ◽  
T. D. Pessoa ◽  
M. V. Rodrigues ◽  
G. Malnic ◽  
A. C. C. Girardi
Keyword(s):  
Protein Phosphatase ◽  
Spontaneously Hypertensive Rats ◽  
Differential Regulation ◽  
Protein Phosphatase 1 ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Before And After

scholarly journals IL-10 treatment decreases blood pressure in male, but not female, spontaneously hypertensive rats

2020 ◽  
Vol 319 (3) ◽  
pp. F359-F365 ◽  
Author(s):  
Ellen E. Gillis ◽  
Jacqueline B. Musall ◽  
Babak Baban ◽  
Jennifer C. Sullivan
Keyword(s):  
Blood Pressure ◽  
T Cells ◽  
Spontaneously Hypertensive Rats ◽  
Interleukin 10 ◽  
Receptor Expression ◽  
No Production ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Before And After ◽  
Chronic Infusion

Interleukin-10 (IL-10) is an anti-inflammatory cytokine that induces nitric oxide (NO) production. IL-10 supplementation has been previously shown to lower blood pressure (BP) in male hypertensive mice, but the effect of exogenous IL-10 in hypertensive female rodents has not been studied. For the present study, we hypothesized that chronic infusion of IL-10 in hypertensive rats would lower BP concomitant with an increase in renal NO synthase (NOS) activity. Male and female spontaneously hypertensive rats (SHRs; 12 wk old) were randomized to receive IL-10 infusion by subcutaneous minipump (3.5 µg·kg−1·day−1) or serve as sham controls ( n = 4–6 rats per treatment per sex). BP was measured by tail cuff before and after 2 wk of treatment. Renal T cells and IL-10 were measured by flow cytometry, and NOS activity was determined by conversion of radiolabeled arginine to radiolabeled citrulline. Female SHRs had greater IL-10+ renal cells than male SHRs and greater expression of the IL-10 receptor at baseline. BP did not change in female SHRs treated with IL-10, but BP significantly decreased following IL-10 infusion in male SHRs. Contrary to our hypothesis, NOS enzymatic activity decreased with IL-10 treatment in the renal inner medulla and cortex of both sexes. Renal regulatory T cells also decreased in both sexes after IL-10 treatment. In conclusion, despite male SHRs having less IL-10 and IL-10 receptor expression in the kidney compared with female SHRs, exogenous IL-10 selectively decreased BP only in male SHRs. Furthermore, our data suggest that exogenous IL-10-induced decreases in BP in male SHRs are not dependent on upregulating renal NOS activity.

Acute exercise and gender alter cardiac autonomic tonus differently in hypertensive and normotensive rats

1998 ◽  
Vol 274 (2) ◽  
pp. R510-R516 ◽  
Author(s):  
Margaret P. Chandler ◽  
Stephen E. Dicarlo
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Acute Exercise ◽  
Female Rats ◽  
Male Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Cardiac Autonomic Regulation ◽  
Before And After ◽  
Wistar Kyoto ◽  
And Gender

Arterial pressure (AP), heart rate (HR), cardiac sympathetic tonus (ST), and parasympathetic tonus (PT) were determined in spontaneously hypertensive rats (SHR, 8 male and 8 female) and Wistar-Kyoto normotensive rats (WKY, 8 male and 12 female) before and after acute exercise. Before exercise, hypertensive rats (regardless of gender) had an increased ST (+15 beats/min), increased resting HR (+12 beats/min), and decreased PT (−11 beats/min). Similarly, female rats (regardless of strain) also had an increased ST (+15 beats/min), increased resting HR (+39 beats/min), and decreased PT (−14 beats/min). Hypertensive rats had a significant reduction in AP (−17 ± 3 mmHg), ST (−26 beats/min), PT (−7 beats/min), and HR (−14 beats/min) after exercise. In contrast, AP was not reduced in normotensive rats and ST (+18 beats/min) and HR (+42 beats/min) were increased in female normotensive rats after exercise. However, male normotensive rats had a postexercise reduction in ST (−14 beats/min) and HR (−19 beats/min). In summary, AP, ST, and resting HR were higher whereas PT was lower in hypertensive vs. normotensive rats. Furthermore, females had a higher resting HR, intrinsic HR, and ST and lower PT than male rats. These data demonstrate that gender and the resting level of AP influence cardiac autonomic regulation.

scholarly journals Enhanced myogenic response in the afferent arteriole of spontaneously hypertensive rats

2010 ◽  
Vol 298 (6) ◽  
pp. H1769-H1775 ◽  
Author(s):  
YiLin Ren ◽  
Martin A. D'Ambrosio ◽  
Ruisheng Liu ◽  
Patrick J. Pagano ◽  
Jeffrey L. Garvin ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Perfusion Pressure ◽  
Intraluminal Pressure ◽  
Myogenic Response ◽  
Afferent Arteriole ◽  
Hypertensive Rats ◽  
Luminal Diameter ◽  
Spontaneously Hypertensive ◽  
Before And After ◽  
Wistar Kyoto

Spontaneously hypertensive rats (SHRs) have normal glomerular capillary pressure even though renal perfusion pressure is higher, suggesting that preglomerular vessels exhibit abnormally high resistance. This may be due to increased superoxide (O2−) production, which contributes to the vasoconstriction in hypertension. We tested the hypothesis that the myogenic response of the afferent arteriole (Af-Art) is exaggerated in SHRs because of increased levels of reactive oxygen species (ROS). Single Af-Arts were microdissected from kidneys of SHRs and Wistar-Kyoto (WKY) rats and microperfused in vitro. When perfusion pressure in the Af-Art was increased stepwise from 60 to 140 mmHg, the luminal diameter decreased by 8.4 ± 2.9% in WKY Af-Arts but fell by 29.3 ± 5.6% in SHR Af-Arts. To test whether ROS production is enhanced during myogenic response in SHRs, we measured chloromethyl-dichlorodihydrofluorescein diacetate acetyl ester (CM-H2DCFDA) florescence before and after increasing intraluminal pressure from 60 to 140 mmHg. Pressure-induced increases in ROS were fourfold greater in SHR Af-Arts compared with WKY Af-Arts (SHR, 48.0 ± 2.2%; and WKY, 12.2 ± 0.3%). To test whether O2− contributes to the myogenic response in SHRs, either the membrane-permeant O2− scavenger Tempol or the nox2-based NADPH oxidase (NOX2) inhibitor gp91 ds-tat were added to the Af-Art lumen and bath and the myogenic response was tested before and after treatment. Both Tempol (10−4 M) and gp91 ds-tat (10−5 M) significantly attenuated the pressure-induced constriction in SHR Af-Arts but not in WKY Af-Arts. We conclude that 1) pressure-induced constriction is exaggerated in SHR Af-Arts, 2) NOX2-derived O2− may contribute to the enhanced myogenic response, and 3) O2− exerts little influence on the myogenic response under normotensive conditions.

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