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.

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.

Intra-Erythrocyte Sodium and (Na+,K+-Activated)-ATPase Concentration and Urinary Aldosterone Excretion in Spontaneously Hypertensive Rats

1981 ◽  
Vol 60 (2) ◽  
pp. 229-232 ◽  
Author(s):  
G. Berglund ◽  
L. Sigström ◽  
S. Lundin ◽  
B. E. Karlberg ◽  
H. Herlitz
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Sodium Concentration ◽  
Intracellular Sodium ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Significant Difference ◽  
Intracellular Sodium Concentration ◽  
Erythrocyte Sodium ◽  
Wistar Kyoto

1. Intra-erythrocyte sodium, potassium, ATP and (Na+,K+-activated)-ATPase concentrations and urinary aldosterone excretion were compared in 3-month-old spontaneously hypertensive rats (n = 11) and normotensive Wistar-Kyoto control rats (n = 11). 2. Spontaneously hypertensive rats exhibited significantly higher intra-erythrocyte sodium concentration (5.5 ± 1.3 vs 4.0 ± 1.1 mmol/l of erythrocytes, P < 0.01). No significant difference was found in intra-erythrocyte potassium, ATP or (Na+,K+-activated)-ATPase concentration. 3. Mean urinary aldosterone excretion was significantly lower in spontaneously hypertensive rats (66.3 ± 6.5 pmol/24 h) than in Wistar-Kyoto rats (90.5 ± 10.6 pmol/24 h, P < 0.01). No significant relationship between urinary aldosterone and intra-erythrocyte sodium concentration was found in spontaneously hypertensive or Wistar-Kyoto rats or in the pooled group. 4. These results are thus consistent with previous findings of an increased intracellular sodium concentration in spontaneously hypertensive rats, but do not support the hypothesis that aldosterone is a dominant regulator of intracellular sodium concentration.

Cytoplasmic free [Ca2+] is not increased in the platelets of deoxycorticosterone–salt and spontaneously hypertensive rats

1986 ◽  
Vol 71 (1) ◽  
pp. 121-123 ◽  
Author(s):  
Koh-Ichi Murakawa ◽  
Yoshiharu Kanayama ◽  
Masakazu Kohno ◽  
Takahiko Kawarabayashi ◽  
Kenichi Yasunari ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Free Calcium ◽  
Sprague Dawley ◽  
Hypertensive Rats ◽  
Acetoxymethyl Ester ◽  
Spontaneously Hypertensive ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Free Calcium Concentration ◽  
Wistar Kyoto

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.

scholarly journals Vasorelaxation effect of Syzygium polyanthum (wight) walp. Leaves extract on isolated thoracic aorta rings of normal and hypertensive rats

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Azlini Ismail ◽  
Wan Amir Nizam Wan Ahmad
Keyword(s):  
Thoracic Aorta ◽  
Spontaneously Hypertensive Rats ◽  
Negative Control ◽  
Distilled Water ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Traditional Remedy ◽  
Ic50 Value ◽  
Significant Difference ◽  
Wistar Kyoto

Introduction: Syzygium polyanthum (Wight) Walp. leaves are traditionally consumed by the Malays as an alternative treatment for hypertension. Until now, effect of S. polyanthum leaves extract on blood vessel is not yet disclosed. Methods: This study investigated the effect of S. polyanthum leaves aqueous extract (AESP) (0.01, 0.1, 1 & 10 mg/ml) on isolated thoracic aorta rings of normotensive Wistar-Kyoto rats (WKY) and Spontaneously Hypertensive rats (SHR). Both rings were pre-contracted using phenylephrine (1 µM). Distilled water that dissolved AESP served as negative control. Results: As compared to negative control, AESP at 0.1, 1, and 10 mg/ml significantly relaxed aorta rings of WKY by 39.81 ± 2.99 % (P<0.001), 59.55 ± 7.60 % (P<0.001), and 72.58 ± 5.57 % (P<0.001), respectively. In SHR, AESP at 1 and 10 mg/ml significantly relaxed the aorta rings of SHR by 40.53 ± 3.66 % (P<0.001) and 65.73 ± 8.24 % (P<0.001), respectively. There was a significant difference between AESP-induced vasorelaxation in WKY and in SHR at a concentration of 0.1 mg/ml (P<0.001). The IC50 value for AESPinduced vasorelaxation on aorta rings of WKY (94.67 ± 1.41 µg/ml) was lower than of SHR (799.80 ± 1.69 µg/ml). Conclusions: The S. polyanthum leaves extract was able to cause significant relaxation on aorta rings of both normal and hypertensive rats. Thus, this finding is well-corroborated with the use of this plant as a traditional remedy for hypertension. It is suggested that an in-depth investigation of  the mechanism of vasorelaxation of this plant is carried-out in the future.

scholarly journals Involvement of iNOS in postischemic heart dysfunction of stroke-prone spontaneously hypertensive rats

2001 ◽  
Vol 280 (2) ◽  
pp. H668-H673 ◽  
Author(s):  
Kohji Abe ◽  
Miwa Tokumura ◽  
Tetsuji Ito ◽  
Takashi Murai ◽  
Akira Takashima ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Heart Weight ◽  
Hypertensive Rats ◽  
Continuous Administration ◽  
Spontaneously Hypertensive ◽  
Heart Dysfunction ◽  
Hemodynamic Deterioration ◽  
Significant Difference ◽  
Permanent Occlusion ◽  
Wistar Kyoto

We investigated the possible contribution of inducible nitric oxide synthase (iNOS) to postischemic heart dysfunction and injuries in stroke-prone spontaneously hypertensive rats (SHRSP). SHRSP, 13–14 wk of age, had significantly higher systolic blood pressure and greater heart weight than age-matched Wistar-Kyoto rats (WKY). Permanent occlusion of the left anterior descending coronary artery (LAD) caused significant and long-lasting increases in the activity and mRNA expression of myocardial iNOS in SHRSP compared with WKY. However, there was no significant difference in the LAD occlusion-induced expression of interleukin-1β mRNA between SHRSP and WKY. Hemodynamic deterioration and myocardial fibrosis were also observed in SHRSP at 4 wk after LAD occlusion. Continuous administration of 2-amino-5,6-dihydro-6-methyl-4 H-1,2-thiazin (AMT) completely blocked the LAD occlusion-induced increase in the myocardial iNOS activity of SHRSP. Moreover, postischemic heart dysfunction and injuries were also significantly ameliorated by 2-amino-5,6-dihydro-6-methyl-4 H-1,2-thiazin (AMT). These results suggest that the increased activity of myocardial iNOS plays a pivotal role in the development of postischemic cardiac dysfunction and injuries in SHRSP with the hypertensive and hypertrophic heart.

Altered intracellular adrenoceptor distribution in myocardium of spontaneously hypertensive rats

1987 ◽  
Vol 253 (4) ◽  
pp. H904-H908 ◽  
Author(s):  
C. J. Limas ◽  
C. Limas
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Beta Agonists ◽  
Significant Difference ◽  
Beta Receptors ◽  
Alpha Receptors ◽  
Total Complement ◽  
Membrane Bound ◽  
Wistar Kyoto

The number of membrane-bound beta-adrenoceptors is reduced in the myocardium of spontaneously hypertensive rats, and this decline may account for the decreased inotropic responsiveness to beta-agonists. It is not known, however, whether the total complement of cellular beta-receptors is lower in hypertensive animals. This issue was examined using two different approaches: acid elution of cell surface-bound beta-receptor ligands and comparison of the number of receptors in the plasma membrane and a postcytosolic vesicular fraction. Approximately 30% of the total beta-receptors were located intracellularly in Wistar-Kyoto rats compared with 42% for spontaneously hypertensive rats. Similarly, a decline in membrane-bound beta-receptors in hypertensive rats was balanced by a rise in receptors associated with the vesicular fraction. In contrast, alpha 1-adrenoceptors were higher in the membrane and lower in the vesicular fraction of hypertensive rats without a significant difference in total alpha-receptors compared with normotensive animals. Differences in adrenergic responsiveness in this, and perhaps other, models of cardiac hypertrophy reflect altered intracellular distribution of adrenoceptors, which may be under the control of the sympathetic nervous system.

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.

Medullospinal sympathoexcitatory neurons in normotensive and spontaneously hypertensive rats

1986 ◽  
Vol 250 (5) ◽  
pp. R910-R917 ◽  
Author(s):  
M. K. Sun ◽  
P. G. Guyenet
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Discharge Rate ◽  
Maximal Activity ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Significant Difference ◽  
Wistar Kyoto ◽  
The Relationship ◽  
Nerve Discharge

Aortic depressor nerve discharge (AND), lumbar sympathetic nerve discharge (SND), and single-unit activity of medullospinal pressure-sensitive neurons of nucleus paragigantocellularis lateralis (PGCL neurons) were recorded in halothane-anesthetized 16-wk-old spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. The relationship between these variables and mean arterial pressure (MAP) was investigated. The gain of baroreceptor afferents was not significantly different between the strains, but corner MAP (intersection between linear ascending portion of curve and noise) was 38 mmHg higher in SHRs. The relationship between SND and MAP and that between PGCL neuronal activity and MAP were both characterized by a plateau (maximal activity) at low MAP followed by a linear reduction reaching zero at a level called cutoff MAP. The theoretical intersection between the plateau and the linear decremental portion of these curves was defined as a corner MAP. Values of corner MAP determined at the three levels (AND, SND, PGCL) were identical in a given strain and reset by a common value in SHRs (38-40 mmHg). The gain of baroreceptor reflex measured at all three sites as the slope of the linear incremental (AND) or decremental (PGCL and sympathetic chain) portion of the activity-MAP relationship was the same in WKY rats and in SHRs. Cutoff MAP measured in PGCL was identical to that measured in peripheral sympathetic system for a given strain. There was no significant difference in maximal discharge rate of PGCL neurons nor in lumbar SND and no interstrain difference in the proportion of SND that was suppressible by arterial baroreceptor feedback.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced sympathetic reactivity to glutamate stimulation in medulla oblongata of spontaneously hypertensive rats

1995 ◽  
Vol 268 (4) ◽  
pp. H1499-H1509 ◽  
Author(s):  
T. L. Yang ◽  
C. Y. Chai ◽  
C. T. Yen
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Significant Difference ◽  
Baseline Adjustment ◽  
Before And After ◽  
Threshold Doses ◽  
Wistar Kyoto ◽  
Alpha Chloralose ◽  
Renal Sympathetic

The distribution and reactivity of vasomotor sites in the ventrolateral (VLM) and dorsomedial medulla (DMM) of stroke-prone spontaneously hypertensive rats (SHRSP), spontaneously hypertensive rats (SHR), and Wistar-Kyoto rats (WKY) were compared. Rats were anesthetized with alpha-chloralose and urethan. Baroreceptor denervation and vagotomy were performed. L-Glutamate (Glu, 10 mM, 30 nl) was microinjected into the DMM or VLM to identify vasoactive sites. The extent and the patterns of distribution of these sites in the three strains of rats were similar. The dose-response curve of the vasoactive site was studied with 1–500 pmol of Glu. The maximum responses of blood pressure and renal sympathetic activity were larger and threshold doses of Glu were lower in hypertensive rats. The significance of the differences among the strains was analyzed before and after adjustment for baseline pressure or activity. Most of the differences were statistically significant before baseline adjustment. After baseline adjustment, many differences between the SHRSP and the WKY remained significant. However, the only significant difference detected between the SHR and the WKY was the threshold dose for eliciting renal sympathetic change in the caudal VLM. These results suggest that there may be a general increase in excitability of the vasomotor neurons in the medulla of the hypertensive rats.

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