Cytosolic free calcium regulation in renal tubules from spontaneously hypertensive rats

1990 ◽  
Vol 258 (1) ◽  
pp. F175-F182 ◽  
Author(s):  
W. R. Jacobs ◽  
C. M. Ferrari ◽  
P. C. Brazy ◽  
L. J. Mandel

Cytosolic free calcium (Caf) was measured in isolated renal cortical tubules from spontaneously hypertensive rats (SHR) and age-matched control Wistar-Kyoto (WKY) rats to evaluate whether the onset of hypertension is associated with a change in Caf. At the same time, the cellular mechanism by which differences in Caf occur between these two strains of rats was examined. Caf was significantly lower in renal tubules from 4- to 5-wk (142 +/- 6 vs. 187 +/- 15 nM), 6- to 7-wk (138 +/- 15 vs. 187 +/- 8 nM), and 8- to 9-wk-old (161 +/- 5 vs. 216 +/- 9 nM) SHR compared with age-matched WKY. The lower Caf in SHR tubules was considered to be the result of either an increase in Ca efflux or a reduction in Ca permeability. To the extent that metabolic inhibitors increased Caf but did not alter the difference between SHR and WKY, a primary difference in Caf efflux was excluded. Conversely, when Ca permeability was altered, either with Ca ionophores or incubation in Ca-free medium, Caf changed in the appropriate direction and the difference between SHR and WKY was no longer apparent. These results demonstrate that 1) the previously reported increase in Caf in circulating cells is not a universal feature of hypertension and 2) the lower Caf in renal tubules from SHR appears to be related to a lower Ca permeability. Whether the differences in Caf between SHR and WKY is a permissive factor for the renal contribution to hypertension remains to be elucidated.

BMC Urology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuki Kyoda ◽  
Koji Ichihara ◽  
Kohei Hashimoto ◽  
Ko Kobayashi ◽  
Fumimasa Fukuta ◽  
...  

Abstract Background Neuroendocrine (NE) cells may have an impact on the development and initial growth of benign prostatic hyperplasia (BPH) according to previous human studies. Methods To explore the relationship of NE cells and BPH development, we compared the density of NE cells and also prostatic weight in spontaneously hypertensive rats (SHR), which develop by aging, and Wistar-Kyoto rats (WKY) as control. The total weights of the epithelium and stroma in the ventral lobes of 8-, 12, 16-, 28- and 56-week-old SHR and WKY were calculated using Image J software. NE cells in the ventral prostatic ducts (VPd) were quantified using immunohistochemical staining for serotonin. Results Although there was no significant difference in the estimated total weight of the epithelium and stroma in the ventral lobes adjusted by body weight (ES weight) between the two groups at 8, 12 and 16 weeks of age, ES weight was significantly greater in the SHR group than in the WKT group at 28 and 56 weeks. The density of NE cells in the VPd decreased with aging in the WKY group, whereas it was sustained until 16 weeks and then decreased with aging in the SHR group. The difference in the density between the two groups was most marked at 16 weeks of age. Conclusion In the natural history of BPH, NE cells may play an important role in the initial development of BPH because sustained density of NE cells in the VPd precedes the development of prostatic hyperplasia.


1981 ◽  
Vol 240 (6) ◽  
pp. H927-H933
Author(s):  
L. J. Heller

Isovolumetric pressure-producing properties of isolated Langendorf-perfused hypertrophied ventricles from adult spontaneously hypertensive rats (SHR) were compared with those of nonhypertrophied ventricles from adult Wistar-Kyoto rats (WKY). SHR ventricles were found to produce greater systolic pressure than WKY ventricles when subjected to similar stimulation and perfusion conditions. Correction for the differences in ventricular mass eliminated the difference between groups. Apparent diastolic pressure at high stimulus rates was higher in SHR than WKY, and SHR developed exaggerated aftercontractions following cessation of high-frequency stimulation. Refractory periods of hypertrophied ventricles determined by paired-pulse stimulation were not found to be different from nonhypertrophied ventricles, but hyperexcitable periods of SHR ventricles were significantly longer than WKY ventricles. In addition, the intrinsic ventricular rate of SHR preparations was significantly greater than that of WKY.


1986 ◽  
Vol 71 (1) ◽  
pp. 121-123 ◽  
Author(s):  
Koh-Ichi Murakawa ◽  
Yoshiharu Kanayama ◽  
Masakazu Kohno ◽  
Takahiko Kawarabayashi ◽  
Kenichi Yasunari ◽  
...  

1. The cytoplasmic free calcium concentration ([Ca2+]i) in the platelets of spontaneously hypertensive rats (SHR), Wistar–Kyoto rats (WKY), deoxycorticosterone–salt hypertensive rats (DOC) and normotensive Sprague–Dawley rats (SD) was measured with the fluorescent dye, quin-2-tetra-acetoxymethyl ester. 2. No significant difference in platelet [Ca2+]i was found between SHR and WKY or between DOC and SD rats. 3. No correlations were found between systolic blood pressure and [Ca2+]i. 4. These results suggest that the elevation of platelet [Ca2+]i does not necessarily accompany hypertension in rats.


1990 ◽  
Vol 3 (8 Pt 2) ◽  
pp. 224S-226S ◽  
Author(s):  
A. Baba ◽  
K. Fukuda ◽  
T. Hano ◽  
M. Shiotani ◽  
H. Yoshikawa ◽  
...  

2012 ◽  
pp. S145-S153 ◽  
Author(s):  
Z. CHARVÁTOVÁ ◽  
I. OŠŤÁDALOVÁ ◽  
J. ZICHA ◽  
J. KUNEŠ ◽  
H. MAXOVÁ ◽  
...  

Hypertension is the risk factor of serious cardiovascular diseases, such as ischemic heart disease and atherosclerosis. The aim of the present study was to analyze the development of cardiac tolerance to ischemia in neonatal spontaneously hypertensive rats (SHR) and possible protective effect of ischemic preconditioning (IP) or adaptation to intermittent high-altitude hypoxia (IHAH). For this purpose we used 1- and 10-day-old pups of SHR and their normotensive control Wistar Kyoto rats (WKY). Isolated hearts were perfused in the Langendorff mode with Krebs-Henseleit solution at constant pressure, temperature and rate. Cardiac tolerance to ischemia was expressed as a percentage of baseline values of developed force (DF) after global ischemia. IP was induced by three 3-min periods of global ischemia, each separated by 5-min periods of reperfusion. IHAH was simulated in barochamber (8 h/day, 5000 m) from postnatal day 1 to 10. Cardiac tolerance to ischemia in 1-day-old SHR was higher than in WKY. In both strains tolerance decreased after birth, and the difference disappeared. The high cardiac resistance in 1- and 10-day-old SHR and WKY could not be further increased by both IP and adaptation to IHAH. It may be concluded that hearts from newborn SHR are more tolerant to ischemia/reperfusion injury as compared to age-matched WKY; cardiac resistance decreased in both strains during the first ten days, similarly as in Wistar rats.


1979 ◽  
Vol 57 (4) ◽  
pp. 438-441 ◽  
Author(s):  
P. J. Stuart ◽  
R. L. Kline ◽  
P. F. Mercer

Renal norepinephrine (NE) concentration was measured in normotensive Wistar–Kyoto (WKY) and spontaneously hypertensive rats (SHR) at 7, 9, 11, and 13 weeks of age. Although the weight of kidneys was similar in the two strains of rats, renal NE concentration was significantly lower in SHR at all ages (147 ± 9 to 175 ± 13 ng/g for SHR, and 216 ± 8 to 262 ± 17 ng/g for WKY rats). The difference in renal NE concentration during this time of rapidly-increasing arterial pressure in the SHR suggests that renal NE may in some way be related to the development of hypertension.


Sign in / Sign up

Export Citation Format

Share Document