Isovolumetric properties of ventricles of spontaneously hypertensive rats

1981 ◽  
Vol 240 (6) ◽  
pp. H927-H933
Author(s):  
L. J. Heller
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Ventricular Rate ◽  
High Frequency Stimulation ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Frequency Stimulation ◽  
The Difference ◽  
Wistar Kyoto

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.

scholarly journals Sustained density of neuroendocrine cells with aging precedes development of prostatic hyperplasia in spontaneously hypertensive rats

BMC Urology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuki Kyoda ◽  
Koji Ichihara ◽  
Kohei Hashimoto ◽  
Ko Kobayashi ◽  
Fumimasa Fukuta ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Prostatic Hyperplasia ◽  
Neuroendocrine Cells ◽  
Initial Growth ◽  
Hypertensive Rats ◽  
Initial Development ◽  
Spontaneously Hypertensive ◽  
Significant Difference ◽  
The Difference ◽  
Wistar Kyoto

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.

scholarly journals Enhanced Protective Effect of the Combination ofUncariaandSemen Raphanion Vascular Endothelium in Spontaneously Hypertensive Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yun-lun Li ◽  
Yue-Hua Jiang ◽  
Chuan-Hua Yang ◽  
Jing-Chang Sun ◽  
Miao-Miao Wang ◽  
...  
Keyword(s):  
Protective Effect ◽  
Thoracic Aorta ◽  
Spontaneously Hypertensive Rats ◽  
Diastolic Pressure ◽  
Heart Diseases ◽  
Mrna Level ◽  
Systolic Pressure ◽  
Low Grade ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Endothelial dysfunction and low-grade inflammation are closely associated with hypertension and other cardiovascular diseases. The combination ofUncaria (U)andSemen Raphani (R)is common in traditional Chinese medicine for the treatment of hypertension and heart diseases. We aimed to investigate the therapeutic effect of the combination ofUncariaandSemen Raphanion spontaneously hypertensive rats (SHRs), and valsartan was used as a positive control. In the present study, all extracts decreased systolic pressure, diastolic pressure, and mean arterial pressure.Ualone showed antihypertensive efficacy and effectively decreased CECs count, whileRalone showed efficacy in relieving inflammatory level. The combination ofUandRshowed enhanced effectiveness at lowering activated CECs and improving endothelial integrity of thoracic aorta and mesenteric artery and normalized the level of plasma biomarkers of endothelial damage. The combination ofUandRdecreased the mRNA level of VCAM-1, Sel-L, TFPI, and Sel-P, while it elevated mRNA expression of FGF-1 and THBD of the thoracic aorta, which may be, at least in part, involved in the mechanism of protective effect on hypertensive endothelial injury.

scholarly journals Cardiac Tolerance to Ischemia in Neonatal Spontaneously Hypertensive Rats

2012 ◽  
pp. S145-S153 ◽  
Author(s):  
Z. CHARVÁTOVÁ ◽  
I. OŠŤÁDALOVÁ ◽  
J. ZICHA ◽  
J. KUNEŠ ◽  
H. MAXOVÁ ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Global Ischemia ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Isolated Hearts ◽  
Baseline Values ◽  
The Difference ◽  
Wistar Kyoto

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.

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
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Metabolic Inhibitors ◽  
Free Calcium ◽  
Renal Tubules ◽  
Hypertensive Rats ◽  
Cytosolic Free Calcium ◽  
Spontaneously Hypertensive ◽  
Circulating Cells ◽  
The Difference ◽  
Wistar Kyoto

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.

Norepinephrine concentration in kidneys of normotensive Wistar–Kyoto and spontaneously hypertensive rats

1979 ◽  
Vol 57 (4) ◽  
pp. 438-441 ◽  
Author(s):  
P. J. Stuart ◽  
R. L. Kline ◽  
P. F. Mercer
Keyword(s):  
Arterial Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Norepinephrine Concentration ◽  
The Difference ◽  
Wistar Kyoto

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.

Differential participation of calcium-activated potassium channel in endothelium-dependent hyperpolarization-type relaxation in superior mesenteric arteries of spontaneously hypertensive rats

2018 ◽  
Vol 96 (8) ◽  
pp. 839-844
Author(s):  
Makoto Ando ◽  
Takayuki Matsumoto ◽  
Shota Kobayashi ◽  
Maika Iguchi ◽  
Kumiko Taguchi ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Combined Treatment ◽  
Mesenteric Arteries ◽  
Hypertensive Rats ◽  
Α Subunit ◽  
Spontaneously Hypertensive ◽  
The Difference ◽  
Wistar Kyoto ◽  
Calcium Activated Potassium Channel ◽  
Relationship Of

The purpose of this study was to determine the relationship of KCa channels to endothelium-dependent hyperpolarizing factor (EDHF)-mediated relaxation induced by acetylcholine (ACh) in the superior mesenteric arteries of 7-month-old spontaneously hypertensive rats (SHR). Upon inhibition of nitric oxide synthase and cyclooxygenase, ACh-induced EDHF-mediated relaxation was found to be weaker in SHR than in age-matched Wistar Kyoto rats (WKY). These relaxations in both group were attenuated by combined treatment with small-conductance and intermediate-conductance Ca2+-activated K+ channels (SKCa and IKCa) inhibitors, with the exception of relaxation resistant to inhibition of these channels in SHR (vs. WKY). Treatment with large-conductance Ca2+-activated K+ channels (BKCa) inhibitor specifically attenuated relaxation in SHR, but not in WKY. Protein expression of IKCa and SKCa in the arteries did not differ between the 2 groups, whereas ratio of sloβ1 subunit to α subunit of BKCa was increased in SHR (vs. WKY). These results suggest that EDHF-mediated relaxations in superior mesenteric arteries are impaired in SHR, and utilize components of BKCa in addition to SKCa/IKCa channel activities, that the increased participation of BKCa may be attributable to alterations in α and sloβ1 subunit ratio, and that components unrelated to KCa activity may also contribute to the difference between SHR and WKY arteries.

Excess oxygen delivery during muscle contractions in spontaneously hypertensive rats

1995 ◽  
Vol 78 (1) ◽  
pp. 101-111 ◽  
Author(s):  
J. M. Lash ◽  
H. G. Bohlen
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Oxygen Delivery ◽  
Spontaneously Hypertensive Rats ◽  
Muscle Contractions ◽  
Hypertensive Rats ◽  
Hemoglobin Oxygen Saturation ◽  
Spontaneously Hypertensive ◽  
Tissue Po2 ◽  
Wistar Kyoto

These experiments determined whether a deficit in oxygen supply relative to demand could account for the sustained decrease in tissue PO2 observed during contractions of the spinotrapezius muscle in spontaneously hypertensive rats (SHR). Relative changes in blood flow were determined from measurements of vessel diameter and red blood cell velocity. Venular hemoglobin oxygen saturation measurements were performed by using in vivo spectrophotometric techniques. The relative dilation [times control (xCT)] of arteriolar vessels during contractions was as large or greater in SHR than in normotensive rats (Wistar-Kyoto), as were the increases in blood flow (2 Hz, 3.50 +/- 0.69 vs. 3.00 +/- 1.05 xCT; 4 Hz, 10.20 +/- 3.06 vs. 9.00 +/- 1.48 xCT; 8 Hz, 16.40 +/- 3.95 vs. 10.70 +/- 2.48 xCT). Venular hemoglobin oxygen saturation was lower in the resting muscle of SHR than of Wistar-Kyoto rats (31.0 +/= 3.0 vs. 43.0 +/- 1.9%) but was higher in SHR after 4- and 8-Hz contractions (4 Hz, 52.0 +/- 4.8 vs. 43.0 +/- 3.6%; 8 Hz, 51.0 +/- 4.6 vs. 41.0 +/- 3.6%). Therefore, an excess in oxygen delivery occurs relative to oxygen use during muscle contractions in SHR. The previous and current results can be reconciled by considering the possibility that oxygen exchange is limited in SHR by a decrease in anatomic or perfused capillary density, arteriovenular shunting of blood, or decreased transit time of red blood cells through exchange vessels.

scholarly journals Aging Additively Influences Insulin- and Insulin-Like Growth Factor-1-Mediated Endothelial Dysfunction and Antioxidant Deficiency in Spontaneously Hypertensive Rats

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 676
Author(s):  
Kunanya Masodsai ◽  
Yi-Yuan Lin ◽  
Sih-Yin Lin ◽  
Chia-Ting Su ◽  
Shin-Da Lee ◽  
...  
Keyword(s):  
Growth Factor ◽  
Endothelial Dysfunction ◽  
Spontaneously Hypertensive Rats ◽  
No Production ◽  
Organ Bath ◽  
Insulin Like Growth Factor ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Nos Inhibitors ◽  
Wistar Kyoto

This study aimed to investigate the aging-related endothelial dysfunction mediated by insulin and insulin-like growth factor-1 (IGF-1) and antioxidant deficiency in hypertension. Male spontaneously hypertensive rats (SHRs) and age-matched normotensive Wistar–Kyoto rats (WKYs) were randomly divided into 24-week-old (younger) and 48-week-old (older) groups, respectively. The endothelial function was evaluated by the insulin- and IGF-1-mediated vasorelaxation of aortic rings via the organ bath system. Serum levels of nitric oxide (NO), malondialdehyde (MDA), catalase, and total antioxidant capacity (TAC) were examined. The insulin- and IGF-1-mediated vasorelaxation was significantly impaired in both 24- and 48-week-old SHRs compared with age-matched WKYs and was significantly worse in the 48-week-old SHR than the 24-week-old SHR. After pretreatments of phosphoinositide 3-kinase (PI3K) or NO synthase (NOS) inhibitors, the insulin- and IGF-1-mediated vasorelaxation became similar among four groups. The serum level of MDA was significantly increased, while the NO, catalase, and TAC were significantly reduced in the 48-week-old SHR compared with the 24-week-old SHR. This study demonstrated that the process of aging additively affected insulin- and IGF-1-mediated endothelial dysfunction in SHRs, which could be partly attributed to the reduced NO production and antioxidant deficiency.

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