The relationship between altered blood vessel structure, hypertension, and the sympathetic nervous system

1985 ◽  
Vol 63 (4) ◽  
pp. 387-391 ◽  
Author(s):  
T. M. Scott ◽  
G. Galway
Keyword(s):  
Sympathetic Innervation ◽  
Diabetic Rats ◽  
Sprague Dawley ◽  
Spontaneously Hypertensive ◽  
Sd Rat ◽  
Vessel Structure ◽  
Wistar Kyoto ◽  
Hypertension Development ◽  
6 Hydroxydopamine ◽  
The Relationship

The relationship between sympathetic innervation and arterial medial development has been examined in normotensive, hypertensive, and diabetic rats. Using the jejunal artery as a model, the number of nerve fibres innervating the artery as determined from fluorescent preparations, and the medial thickness and lumen diameter as measured from resin embedded specimens were correlated from animals prepared in various ways. The rats used were normal Sprague–Dawley (SD), SD with induced hypertension, SD with diabetes induced with streptozotocin, SD sympathectomized with 6-hydroxydopamine, spontaneously hypertensive rats (SHR), SHR treated with capsaicin to prevent hypertension development, Wistar Kyoto rats (WKY), and WKY treated with capsaicin. Examination of the jejunal arteries from these rats at 12 weeks of age following normal development, or 8 weeks of hypertension development, or 8 and 12 weeks of diabetes, showed that increased innervation occurred in the SHR under all conditions, and in the diabetic rats after 8 weeks of diabetes. Medial hypertrophy occurred in the SHR and in the SD hypertensive only. It is concluded that the special relationship which exists between the sympathetic innervation and arterial media in the SHR does not occur during hypertension development in the SD rat, nor is it necessary for normal medial development in the SD rat. The sympathetic innervation does appear to have a trophic influence on vascular smooth muscle of diabetic rats, at least in the early stages of the disease.

Age-dependent overflow of endogenous norepinephrine from paraventricular hypothalamic nucleus of hypertensive rats

1993 ◽  
Vol 265 (1) ◽  
pp. H39-H46 ◽  
Author(s):  
J. M. Qualy ◽  
T. C. Westfall
Keyword(s):  
Blood Pressure ◽  
Neuronal Activity ◽  
Reciprocal Relationship ◽  
Hypothalamic Nucleus ◽  
Sprague Dawley ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Paraventricular Hypothalamic Nucleus ◽  
Wistar Kyoto ◽  
The Relationship

The relationship between age and central noradrenergic neuronal activity of the paraventricular hypothalamic nucleus (PVH) was examined in 7- to 10-, 12- to 14-, and 30- to 36-wk-old Sprague-Dawley (SD), Wistar-Kyoto (WKY), and spontaneously hypertensive rats (SHR). As an index of noradrenergic activity, endogenous norepinephrine (NE) overflow was assessed utilizing a miniaturized push-pull cannula assembly in unanesthetized freely moving rats. NE overlow under basal, 56 mM K+ stimulation, and in response to pressor/depressor drugs, were examined in all three strains at all ages. Significant increases in basal and K(+)-stimulated overflow of endogenous NE from the PVH were observed in all ages of SHR compared with normotensive controls with the greatest percent increase occurring during the development of hypertension in SHR. In addition, a reciprocal relationship exists with respect to blood pressure and overflow of NE from the PVH such that increases/decreases in blood pressure elicit decreases/increases in NE overflow in all strains at all ages examined. However, developing hypertensive SHR exhibited attenuated decreases in overflow of NE from the PVH compared with age-matched controls and established hypertensive SHR. These results suggest that noradrenergic pathways of the PVH contribute to the development and maintenance of arterial pressure hemostasis and that enhanced central noradrenergic neuronal activity is greatest during the development of hypertension in SHR.

scholarly journals Increased superoxide levels in ganglia and sympathoexcitation are involved in sarafotoxin 6c-induced hypertension

2008 ◽  
Vol 295 (5) ◽  
pp. R1546-R1554 ◽  
Author(s):  
Melissa Li ◽  
Xiaoling Dai ◽  
Stephanie Watts ◽  
David Kreulen ◽  
Gregory Fink
Keyword(s):  
Blood Pressure ◽  
Sympathetic Innervation ◽  
Sympathetic Ganglia ◽  
Plasma Norepinephrine ◽  
Sprague Dawley ◽  
Surgical Ablation ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Induced Hypertension ◽  
Hypertension Development

Endothelin (ET) type B receptors (ETBR) are expressed in multiple tissues and perform different functions depending on their location. ETBR mediate endothelium-dependent vasodilation, clearance of circulating ET, and diuretic effects; all of these should produce a fall in arterial blood pressure. However, we recently showed that chronic activation of ETBR in rats with the selective agonist sarafotoxin 6c (S6c) causes sustained hypertension. We have proposed that one mechanism of this effect is constriction of capacitance vessels. The current study was performed to determine whether S6c hypertension is caused by increased generation of reactive oxygen species (ROS) and/or activation of the sympathetic nervous system. The model used was continuous 5-day infusion of S6c into male Sprague-Dawley rats. No changes in superoxide anion levels in arteries and veins were found in hypertensive S6c-treated rats. However, superoxide levels were increased in sympathetic ganglia from S6c-treated rats. In addition, superoxide levels in ganglia increased progressively the longer the animals received S6c. Treatment with the antioxidant tempol impaired S6c-induced hypertension and decreased superoxide levels in ganglia. Acute ganglion blockade lowered blood pressure more in S6c-treated rats than in vehicle-treated rats. Although plasma norepinephrine levels were not increased in S6c hypertension, surgical ablation of the celiac ganglion plexus, which provides most of the sympathetic innervation to the splanchnic organs, significantly attenuated hypertension development. The results suggest that S6c-induced hypertension is partially mediated by sympathoexcitation to the splanchnic organs driven by increased oxidative stress in prevertebral sympathetic ganglia.

scholarly journals ACE Inhibitory and Antihypertensive Activities of Wine Lees and Relationship among Bioactivity and Phenolic Profile

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 679
Author(s):  
Raúl López-Fernández-Sobrino ◽  
Jorge R. Soliz-Rueda ◽  
Maria Margalef ◽  
Anna Arola-Arnal ◽  
Manuel Suárez ◽  
...  
Keyword(s):  
Hypotensive Effect ◽  
Wine Industry ◽  
Antihypertensive Activity ◽  
Spontaneously Hypertensive ◽  
Lowering Effect ◽  
Before And After ◽  
Phenolic Profiles ◽  
Wistar Kyoto ◽  
Grape Varieties ◽  
The Relationship

Wine lees (WL) are by-products generated in the winemaking process. The aim of this study was to investigate the angiotensin-converting enzyme inhibitory (ACEi) activity, and the blood pressure (BP) lowering effect of WL from individual grape varieties. The relationship among their activities and phenolic profiles was also studied. Three WL, from Cabernet, Mazuela, and Garnacha grape varieties, were firstly selected based on their ACEi properties. Their phenolic profiles were fully characterized by UHPLC-ESI-Q-TOF-MS. Then, their potential antihypertensive effects were evaluated in spontaneously hypertensive rats (SHR). BP was recorded before and after their oral administrations (2, 4, 6, 8, 24, and 48 h) at a dose of 5 mL/kg bw. Cabernet WL (CWL) exhibited a potent antihypertensive activity, similar to that obtained with the drug Captopril. This BP-lowering effect was related to the high amount of anthocyanins and flavanols present in these lees. In addition, a potential hypotensive effect of CWL was discarded in normotensive Wistar–Kyoto rats. Finally, the ACEi and antihypertensive activities of CWL coming from a different harvest were confirmed. Our results suggest the potential of CWL for controlling arterial BP, opening the door to commercial use within the wine industry.

Acute renal denervation produces a diuresis and natriuresis in young SHR but not WKY rats

1986 ◽  
Vol 251 (4) ◽  
pp. F655-F661 ◽  
Author(s):  
M. A. Rudd ◽  
R. S. Grippo ◽  
W. J. Arendshorst
Keyword(s):  
Sodium Excretion ◽  
Renal Denervation ◽  
Strain Differences ◽  
Urine Flow ◽  
Sprague Dawley ◽  
Renal Vasculature ◽  
Renal Nerve ◽  
Water Excretion ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

Clearance experiments were conducted to determine the effect of acute unilateral renal denervation (DNX) on renal hemodynamics and salt and water excretion in anesthetized 6-wk-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto genetic control rats (WKY). Before DNX, SHR had higher mean arterial pressure (33%) and renal vascular resistance (RVR) (57%) and lower glomerular filtration rate (GFR) (10%); urine flow and sodium excretion were similar. Following DNX in SHR, sodium and water excretion increased by 138 and 62%, respectively (P less than 0.001); GFR and RVR were unchanged. In contrast, DNX in WKY did not affect urine flow (0%) or sodium excretion (-21%). These strain differences were observed in Okamoto-Aoki rats from two sources. Effective DNX was indicated by 95% reduction of norepinephrine content 3 days after DNX in both strains. Six-week-old Sprague-Dawley and Munich-Wistar rats, in contrast to WKY, responded to DNX with a natriuresis (+182%) and diuresis (+95%) (P less than 0.001). Renal function was unaffected by sham DNX in SHR. Our results indicate that efferent renal nerve activity has little tonic influence on the renal vasculature in these young rats. Augmented neurotransmitter release and/or tubular responsiveness may be involved in fluid and electrolyte retention and the pathogenesis of hypertension in SHR. Conversely, blunted renal neuroeffector responses may prevent WKY from developing hypertension.

High-NaCl diets increase natriuretic and diuretic responses in salt-resistant but not salt-sensitive SHR

1991 ◽  
Vol 260 (6) ◽  
pp. F890-F897 ◽  
Author(s):  
M. S. Mozaffari ◽  
S. Jirakulsomchok ◽  
Z. H. Shao ◽  
J. M. Wyss
Keyword(s):  
Arterial Pressure ◽  
Renal Denervation ◽  
Isotonic Saline ◽  
Renal Nerves ◽  
Sprague Dawley ◽  
Volume Loading ◽  
Spontaneously Hypertensive ◽  
Volume Load ◽  
Sprague Dawley Rats ◽  
Wistar Kyoto

This study tested the hypothesis that NaCl-sensitive spontaneously hypertensive rats (SHR-S) display a defect in natriuretic and diuretic responses to acute volume loading that contributes to the rise in arterial pressure observed when the rats are fed a high-NaCl diet. Seven-week-old SHR-S and NaCl-resistant SHR rats (SHR-R) and normotensive (Wistar-Kyoto and Sprague-Dawley rats) were fed high- or basal NaCl diets. After 2.5 wk on the diets, preinstrumented conscious rats received an intravenous infusion (5% body wt; 0.5 ml/min) of isotonic saline, and urine was collected through a bladder catheter for 90 min. Control rats on the high-NaCl diet (compared with basal) excreted a significantly greater percentage of Na+ and volume load. In contrast, SHR-S on high-NaCl diet (compared with basal) had a very small increase in natriuretic response and no increase in diuretic response to volume expansion. The effect of renal denervation on natriuretic and diuretic responses to volume load was tested. In SHR-R on 1 and 8% NaCl diets, renal denervation had little or no effect on these responses, suggesting that renal nerves do not play a prominent role in the dietary NaCl-induced increases in the natriuretic and diuretic responses to volume load. These results demonstrate that NaCl-resistant rats rapidly adapt to diets high in NaCl content with increased natriuretic and diuretic responses to acute volume loading. The failure of SHR-S to adapt to the dietary challenge may result in volume loading and a secondary increase in arterial pressure after feeding.

Cardiac function in spontaneously hypertensive diabetic rats

1986 ◽  
Vol 251 (3) ◽  
pp. H571-H580 ◽  
Author(s):  
B. Rodrigues ◽  
J. H. McNeill
Keyword(s):  
Cardiac Function ◽  
Heart Function ◽  
Myocardial Dysfunction ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto ◽  
Developed Pressure ◽  
Working Heart ◽  
Diabetes Induction

The isolated perfused working heart was used to study hypertensive diabetes-induced alterations in cardiac function at 6 and 12 wk after diabetes was induced. At 6 wk after diabetes induction, cardiac performance was depressed in the diabetic animals. However, there was no difference in cardiac function between normotensive Wistar and spontaneously hypertensive (SHR) diabetic rats. Wistar-Kyoto (WKY) rats were also included as normotensive controls in our 12-wk study. Hearts from 12-wk SHR and Wistar diabetic animals exhibited a depressed left ventricular developed pressure and positive and negative dP/dt when compared with control animals. However, this depression was not seen in the WKY diabetic animals. In addition, quantitation of various parameters of heart function revealed highly significant differences between SHR diabetic animals and all other groups associated with an increased mortality. Serum lipids were elevated in SHR and Wistar and were unaffected in WKY diabetic rats. Furthermore, thyroid hormone levels were not depressed in WKY diabetic rats as seen in the other two diabetic groups. This normal lipid metabolism and thyroid status could, in part, explain the lack of cardiac dysfunction in these animals. The data provide further evidence that the combination of hypertension and diabetes mellitus produces greater myocardial dysfunction than with either disease alone and is associated with a significant mortality.

Distribution of kallikrein-binding protein mRNA in kidneys and difference between SHR and WKY rats

1994 ◽  
Vol 267 (2) ◽  
pp. F325-F330 ◽  
Author(s):  
T. Yang ◽  
Y. Terada ◽  
H. Nonoguchi ◽  
M. Tsujino ◽  
K. Tomita ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Binding Protein ◽  
Collecting Duct ◽  
Cortical Collecting Duct ◽  
Sprague Dawley ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Sd Rats ◽  
Medullary Collecting Duct ◽  
Wistar Kyoto

We investigated kallikrein-binding protein (KBP) mRNA distribution in the kidney of Sprague-Dawley (SD) rats, spontaneously hypertensive rats (SHR), and Wistar-Kyoto strain (WKY) rats. Northern blot analysis revealed that KBP mRNA was located mainly in the medulla and with lower amounts in SHR than in WKY rats. KBP mRNA in microdissected nephron segments was detected by reverse transcription and polymerase chain reaction (RT-PCR) followed by Southern blot analysis. In SD rats, the most abundant signals were consistently found in inner medullary collecting duct (IMCD), with small amounts in outer medullary collecting duct, proximal convoluted tubule, and glomerulus. No signals were found in connecting tubule and cortical collecting duct. The nephron distribution of KBP mRNA was similar in WKY and SD rats. Only a small amount of signal was found, however, in IMCD of SHR. In conclusion, 1) KBP mRNA was predominantly distributed in the medullary segments of the distal nephron, downstream from the known kallikrein activity site in the collecting duct, and 2) KBP mRNA expression was significantly decreased in the kidney of SHR.

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