scholarly journals Influence of Age on Anticontractile Effect of Perivascular Adipose Tissue in Normotensive and Hypertensive Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Anna Zemančíková ◽  
Jozef Török
Keyword(s):  
Adipose Tissue ◽  
Vascular Dysfunction ◽  
Age Groups ◽  
Isometric Tension ◽  
Mesenteric Arteries ◽  
Hypertensive Rats ◽  
Perivascular Adipose Tissue ◽  
Contractile Responses ◽  
Wky Rats ◽  
Wistar Kyoto

Perivascular adipose tissue (PVAT) and its vasomodulatory effects play an important role in the physiology and pathophysiology of blood vessels. Alterations in PVAT associated with reduction in its anticontractile influence are proven to contribute to vascular dysfunction in hypertension. The aim of this study was to examine whether the changes in PVAT properties could participate in progression of vascular abnormalities in developing spontaneously hypertensive rats (SHR). Normotensive Wistar-Kyoto (WKY) rats and SHR, both in 5th and in 12th week of age, were used. Systolic blood pressure was similar between WKY rats and SHR in 5th week of age; however, in 12th week, it was significantly increased in SHR comparing to WKY rats. The amount of retroperitoneal fat was higher in WKY rats in both age groups, whereas body weight was higher in WKY rats only in 12th week, when compared to age-matched SHR. From isolated superior mesenteric arteries, two ring preparations were prepared for isometric tension recording, one with PVAT intact and other with PVAT removed. In WKY rats as well as in SHR, arterial contractile responses to noradrenaline, applied cumulatively on rings, were significantly inhibited in the presence of intact PVAT. In both age groups, anticontractile effect of PVAT was higher in WKY rats than in SHR. Neurogenic contractions, induced by electrical stimulation of perivascular sympathoadrenergic nerves, were significantly attenuated in the presence of PVAT in WKY mesenteric arteries from both age groups; however, in arteries from SHR, intact PVAT had no influence on this type of contractile responses. The results suggest that in SHR impairment of anticontractile effect of PVAT precedes hypertension and might contribute to its development.

scholarly journals Effect of Perivascular Adipose Tissue on Arterial Adrenergic Contractions in Normotensive and Hypertensive Rats With High Fructose Intake

2017 ◽  
pp. S537-S544
Author(s):  
A. ZEMANČÍKOVÁ ◽  
J. TÖRÖK
Keyword(s):  
Adipose Tissue ◽  
Mesenteric Arteries ◽  
Heart Weight ◽  
Inhibitory Influence ◽  
Moderate Increase ◽  
Hypertensive Rats ◽  
Perivascular Adipose Tissue ◽  
Contractile Responses ◽  
Fructose Intake ◽  
High Fructose

The aim of this study was to investigate the effect of high fructose intake associated with moderate increase in adiposity on rat arterial adrenergic responses and their modulation by perivascular adipose tissue (PVAT). After eight-week-lasting substitution of drinking water with 10 % fructose solution in adult normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), their systolic blood pressure, plasma triglycerides, and relative liver weight were elevated when compared to their respective control groups. Moreover, in SHR, body weight and relative heart weight were increased after treatment with fructose. In superior mesenteric arteries, PVAT exerted inhibitory influence on adrenergic contractile responses and this effect was markedly stronger in control WKY than in SHR. In fructose-administered WKY, arterial adrenergic contractions were substantially reduced in comparison with the control group; this was caused mainly by enhancement of anticontractile action of PVAT. The diminution of the mesenteric arterial contractions was not observed after fructose treatment in SHR. We conclude that the increase in body adiposity due to fructose overfeeding in rats might have pro-hypertensive effect. However, in WKY it might cause PVAT-dependent and independent reduction in arterial contractile responses to adrenergic stimuli, which could attenuate the pathological elevation in vascular tone.

Abstract 260: Aging Decreases the Anticontractile Effect of Perivascular Adipose Tissue in the Mouse Aorta

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Theodora Szasz ◽  
Maria Alicia Carrillo-Sepulveda ◽  
R Clinton Webb
Keyword(s):  
Adipose Tissue ◽  
Hydrogen Sulfide ◽  
Vascular Dysfunction ◽  
Age Groups ◽  
Bioactive Molecules ◽  
Perivascular Adipose Tissue ◽  
Contractile Responses ◽  
Presence And Absence ◽  
Relaxation Responses ◽  
Mouse Aorta

The perivascular adipose tissue (PVAT) exerts an anticontractile effect via paracrine release of bioactive molecules. During vascular dysfunction associated with hypertension and obesity the anticontractile effect of PVAT is reduced or lost. Although vascular dysfunction associated with aging is well documented, there are no studies investigating whether PVAT plays a role in this context. We hypothesized that the PVAT anticontractile effect would be reduced with age. Mouse aorta from 3 and 9 month-old male C57bl6 mice was used in contractility experiments in the presence and absence of PVAT. Contractile responses to phenylephrine (PE) and serotonin (5-HT) were reduced in the presence of PVAT in both age groups (pD2 PE: young-PVAT=7.13±0.09, young+PVAT=6.24±0.09, old-PVAT=6.96±0.12, old+PVAT=6.49±0.18; pD2 5-HT: young-PVAT=6.74±0.08, young+PVAT=5.98±0.16, old-PVAT=6.58±0.08, old+PVAT=6.29±0.09). Relaxation responses to acetylcholine were not significantly changed by PVAT in either group. Despite an increased PVAT mass in the older mice, the magnitude of the anticontractile effect of PVAT was reduced in older compared to younger mice (% reduction PE contraction: young=66.6±7.8, old=49,1±15.4; % reduction 5-HT contraction: young=55.5±15.1, old=31.9±9.1). Inhibition of cystathionine gamma lyase (CSE), a hydrogen sulfide synthesizing enzyme, did not reverse the reduced 5-HT-induced contraction in PVAT intact aorta in either group. Our results show that the anticontractile effect of PVAT is reduced with age, potentially contributing to the vascular dysfunction observed in aging.

Contractile responses and signal transduction of endothelin-1 in aorta and mesenteric vasculature of adult spontaneously hypertensive rats

1993 ◽  
Vol 71 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Paul V. Nguyen ◽  
Xiao-Ping Yang ◽  
Guo Li ◽  
Li Yuan Deng ◽  
Jean-Pierre Flückiger ◽  
...  
Keyword(s):  
Inositol Phosphates ◽  
Second Messengers ◽  
Resistance Arteries ◽  
Hypertensive Rats ◽  
Contractile Responses ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Mesenteric Arterial Bed ◽  
Mesenteric Vessels ◽  
Wistar Kyoto

The contractile responses and generation of intracellular second messengers in response to endothelin-1 (ET-1), a potent vasoconstrictor peptide released locally by endothelial cells and involved in the regulation of vascular tone, were investigated in different segments of the vascular tree of adult 18-week-old spontaneously hypertensive rats (SHR) as compared with age-matched Wistar–Kyoto (WKY) rats. Aorta rings of SHR showed lower maximum response to ET-1 in comparison with WKY rats. Rings of the main superior mesenteric artery of SHR and WKY showed similar responses to ET-1. Small mesenteric resistance arteries of SHR, mounted on a wire myograph, developed similar tension to those of WKY rats in response to ET-1. The dose–response of inositol phosphates to ET-1 was significantly blunted in thoracic aorta of SHR compared with WKY rats, whereas it was similar in the mesenteric arterial bed. Baseline 1,2-diacylglycerol content was higher in thoracic aorta of SHR than WKY, while it was similar in the mesenteric arterial bed of the two strains. The response of 1,2-diacylglycerol to ET-1 was blunted in aorta of SHR, whereas no significant differences in diacylglycerol accumulation could be found in mesenteric vessels between SHR and WKY. In small mesenteric arteries, the dose–response to ET-1 of cytosolic free calcium, measured with the fluorescent dye Fura 2-AM, was similar in the two groups of rats. We conclude that in the aorta of 18-week-old SHR there is reduced generation of second messengers (inositol phosphates and diacylglycerol), which underlies its decreased response to ET-1 In mesenteric vessels (both proximal and distal) signal transduction is similar in SHR and WKY, and as a result contractile responses in both species are comparable. The responses to ET-1 of the arterial tree in terms of contractility and second messenger generation may reflect the adaptive processes taking place as a consequence of elevated blood pressure within the arterial wall of different segments of the vasculature of SHR.Key words: inositol phosphate, phospholipids, diacylglycerol, cytosolic calcium, second messengers, conduit and resistance arteries, Wistar–Kyoto rats.

scholarly journals Vasomotor action of androgens in the mesenteric artery of hypertensive rats. Role of perivascular innervation

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246254
Author(s):  
Lucía Isidoro-García ◽  
Diva M. Villalpando ◽  
Mercedes Ferrer
Keyword(s):  
Mesenteric Artery ◽  
Electrical Field Stimulation ◽  
Mesenteric Arteries ◽  
Hypertensive Rats ◽  
No Donor ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Vasomotor Function ◽  
Wistar Kyoto ◽  
And Function

Androgens may exert cardiovascular protective actions by regulating the release and function of different vascular factors. In addition, testosterone (TES) and its 5-reduced metabolites, 5α- and 5β-dihydrotestosterone (5α- and 5β-DHT) induce vasorelaxant and hypotensive effects. Furthermore, hypertension has been reported to alter the release and function of the neurotransmitters nitric oxide (NO), calcitonin gene-related peptide (CGRP) and noradrenaline (NA). Since the mesenteric arteries possess a dense perivascular innervation and significantly regulate total peripheral vascular resistance, the objective of this study was to analyze the effect of TES, 5α- and 5β-DHT on the neurogenic release and vasomotor function of NO, CGRP and NA. For this purpose, the superior mesenteric artery from male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats was used to analyze: (i) the effect of androgens (10 nM, incubated for 30 min) on the neurogenic release of NO, CGRP and NA and (ii) the vasoconstrictor-response to NA and the vasodilator responses to the NO donor, sodium nitroprusside (SNP) and exogenous CGRP. The results showed that TES, 5α- or 5β-DHT did not modify the release of NO, CGRP or NA induced by electrical field stimulation (EFS) in the arteries of SHR; however, in the arteries of WKY rats androgens only caused an increase in EFS-induced NO release. Moreover, TES, and especially 5β-DHT, increased the vasodilator response induced by SNP and CGRP in the arteries of SHR. These findings could be contributing to the hypotensive/antihypertensive efficacy of 5β-DHT previously described in conscious SHR and WKY rats, pointing to 5β- DHT as a potential drug for the treatment of hypertension.

scholarly journals Interaction of Perivascular Adipose Tissue and Sympathetic Nerves in Arteries From Normotensive and Hypertensive Rats

2016 ◽  
pp. S391-S399 ◽  
Author(s):  
J. TÖRÖK ◽  
A. ZEMANČÍKOVÁ ◽  
Z. KOCIANOVÁ
Keyword(s):  
Adipose Tissue ◽  
Electrical Stimulation ◽  
Mesenteric Artery ◽  
Sympathetic Nerves ◽  
Mesenteric Arteries ◽  
Inhibitory Influence ◽  
Hypertensive Rats ◽  
Response Curves ◽  
Perivascular Adipose Tissue ◽  
Endogenous Noradrenaline

The inhibitory action of perivascular adipose tissue (PVAT) in modulation of arterial contraction has been recently recognized and contrasted with the prohypertensive effect of obesity in humans. In this study we demonstrated that PVAT might have opposing effect on sympatho-adrenergic contractions in different rat conduit arteries. In superior mesenteric artery isolated from normotensive Wistar-Kyoto rats (WKY), PVAT exhibited inhibitory influence on the contractions to exogenous noradrenaline as well as to endogenous noradrenaline released from arterial sympathetic nerves during transmural electrical stimulation or after application of tyramine. In contrast, the abdominal aorta with intact PVAT responded with larger contractions to transmural electrical stimulation and tyramine when compared to the aorta after removing PVAT; the responses to noradrenaline were similar in both. This indicates that PVAT may contain additional sources of endogenous noradrenaline which could be responsible for the main difference in the modulatory effect of PVAT on adrenergic contractions between abdominal aortas and superior mesenteric arteries. In spontaneously hypertensive rats (SHR), the anticontractile effect of PVAT in mesenteric arteries was reduced, and the removal of PVAT completely eliminated the difference in the dose-response curves to exogenous noradrenaline between SHR and WKY. These results suggest that in mesenteric artery isolated from SHR, the impaired anticontractile influence of PVAT might significantly contribute to its increased sensitivity to adrenergic stimuli.

Spontaneously hypertensive rat resistance artery structure related to myogenic and mechanical properties

2001 ◽  
Vol 101 (4) ◽  
pp. 385-393 ◽  
Author(s):  
Stuart J. BUND
Keyword(s):  
Spontaneously Hypertensive Rat ◽  
Wall Stress ◽  
Mesenteric Arteries ◽  
Maximum Pressure ◽  
Resistance Arteries ◽  
Contractile Responses ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Wall Stiffness ◽  
Wistar Kyoto

This investigation related arterial structure to myogenic (pressure-dependent) contractile responses in resistance arteries from spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) normotensive control rats under pressurized conditions in vitro. Femoral and mesenteric resistance arteries from either strain were cannulated and pressurized in an arteriograph for the determination of pressure-diameter relationships under passive and active conditions in the range 5-200mmHg transmural pressure. Arterial geometrical measurements were made under relaxed conditions at 100mmHg. Media thickness/lumen diameter (M/L) ratios were significantly increased in SHR femoral (5.00±0.44% compared with 3.63±0.34%; P<0.05) and mesenteric (4.40±0.29% compared with 2.62±0.23%; P<0.001) arteries compared with those from WKY rats. Maximum myogenic contractions, assessed as minimum normalized diameters, were not significantly different in SHR and WKY rat femoral (0.41±0.03 and 0.40±0.02 respectively) or mesenteric (0.56±0.02 and 0.63±0.03 respectively) arteries. Arterial mechanical analyses demonstrated that incremental elastic modulus is reduced in SHR mesenteric arteries, but is not significantly different in SHR femoral arteries, compared with those from WKY rats. Additionally, wall stress at estimated in vivo pressures under passive and active conditions are similar in SHR and WKY rat arteries. These data demonstrate that increased M/L ratios in resistance arteries from SHRs are not associated with increased maximum pressure-dependent contractile responses. Increased M/L ratios in resistance arteries from SHRs are not accounted for by increased vessel wall stiffness, but the hypertension-associated arterial geometrical abnormalities act to normalize wall stress in the face of increased arterial pressure.

Abstract P291: High Fat Diet Promotes Hypertension and Vascular Remodeling but Not Vascular Fibrosis or Altered Contractility in Dahl Salt Sensitive Rats

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Roxanne Fernandes ◽  
Patricia A Perez Bonilla ◽  
Hannah Garver ◽  
James J Galligan ◽  
Gregory D Fink ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
Vascular Remodeling ◽  
Vascular Reactivity ◽  
Vascular Dysfunction ◽  
Mesenteric Arteries ◽  
High Fat ◽  
Perivascular Adipose Tissue ◽  
Morphological Studies

Obesity associated hypertension in rodent models is commonly associated with altered vascular reactivity to sympathetic neurotransmitters and inflammation-induced vascular remodeling/fibrosis. Dahl salt-sensitive (SS) rats exhibit elevated sympathetic activity and vascular remodeling. We hypothesized that diet-induced obesity in Dahl SS rats would promote hypertension, vascular dysfunction and remodeling/fibrosis. Male Dahl SS rats were placed on high fat diet (HFD, 60% kcal from fat with final concentrations of 0.33% NaCl and 1% K + , n=5) or normal-fat diet (NFD; 10% kcal from fat, 0.24% NaCl, 0.36% K + , n=5) for 24-26 weeks after weaning (3 weeks of age). Compared with NFD rats, HFD rats displayed severe hypertension (MAP, 165±4 mmHg vs 133±6 mmHg, P<0.05), higher body-weight (470±6g vs 433±7g, P<0.05), and hyperlipidemia (cholesterol, 211±22 mg/dl vs 138±23 mg/dl, P=0.05). HFD rats did not show significant changes in plasma levels of fasting glucose (85±5 mg/dl vs 75±5 mg/dl), insulin (2.6±0.8 ng/ml vs 2.2±1.1 ng/ml), leptin (0.77±0.18 ng/ml vs 0.44±0.06 ng/ml), or aldosterone (249±3 pg/ml vs 234±3 pg/ml) (all P>0.05). HFD did not affect pressurized mesenteric arterial (~300 μm inner diameter, 60 mmHg) reactivity to norepinephrine or ATP in vitro . Pressurized mesenteric arteries from HFD rats displayed thicker walls (Ca 2+ free buffer, 40±1 μm vs 36±1 μm, P<0.05), but showed slightly increased distensibility. Morphological studies did not reveal greater fibrosis in adventitia of mesenteric, intrarenal and coronary arteries from HFD rats. However, HFD induced inflammation in mesenteric perivascular adipose tissue, as shown by increased CD3 positive cell infiltration and histological evidence of fibrosis and angiogenesis. Our studies indicate that HFD in male Dahl SS rats promotes hypertension, perivascular adipose tissue inflammation and vascular remodeling, but not vascular fibrosis. Alteration of vascular contractility to sympathetic neurotransmitters, however, is not required for obesity associated hypertension in Dahl SS rats.

Alteration of perivascular adipose tissue function in angiotensin II-induced hypertension

2009 ◽  
Vol 87 (11) ◽  
pp. 944-953 ◽  
Author(s):  
Robert M.K.W. Lee ◽  
Lili Ding ◽  
Chao Lu ◽  
Li-Ying Su ◽  
Yu-Jing Gao
Keyword(s):  
Blood Pressure ◽  
Adipose Tissue ◽  
Angiotensin Ii ◽  
Vascular Function ◽  
Wistar Rats ◽  
Mesenteric Arteries ◽  
Resistance Arteries ◽  
Hypertensive Rats ◽  
Perivascular Adipose Tissue ◽  
And Control

We studied the role of perivascular adipose tissue (PVAT) in the control of vascular function in an in vivo experimental model of hypertension produced by angiotensin II infusion by osmotic minipump in adult male Wistar rats. Two weeks after infusion with angiotensin II, blood pressure in treated rats was significantly elevated but heart rate was reduced compared with control rats infused with physiological saline. Contraction of aorta from the 2 groups of rats in response to phenylephrine or serotonin was significantly attenuated by the presence of PVAT in both the presence and absence of endothelium. This attenuation effect on contraction to phenylephrine was higher, however, in vessels from control rats than in vessels from hypertensive rats in the absence of endothelium. In the mesenteric resistance arteries, lumen diameter was larger in both hypertensive and control vessels with intact PVAT than in vessels with PVAT removed. The medial wall was thicker in arteries from hypertensive rats. The presence of PVAT potentiated the contraction induced by KCl in mesenteric arteries from control rats, but not in hypertensive rats. PVAT also attenuated the contraction of mesenteric arteries in response to phenylephrine or serotonin in both hypertensive and control groups. Mesenteric arteries from hypertensive rats were more responsive to stimulation by serotonin than those from control rats. We conclude that the increased blood pressure of Wistar rats that occurred after infusion with angiotensin II was associated with changes in the functions of PVAT in the aorta and mesenteric arteries and in the structure and function of resistance arteries.

scholarly journals Perivascular adipose tissue-derived adiponectin activates BKCa channels to induce anticontractile responses

2013 ◽  
Vol 304 (6) ◽  
pp. H786-H795 ◽  
Author(s):  
Fiona M. Lynch ◽  
Sarah B. Withers ◽  
Zhihong Yao ◽  
Matthias E. Werner ◽  
Gill Edwards ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Knockout Mice ◽  
Wild Type Mouse ◽  
Mesenteric Arteries ◽  
Wild Type ◽  
Bkca Channels ◽  
Perivascular Adipose Tissue ◽  
Contractile Responses ◽  
Small Arteries ◽  
Oxide Synthase

This study aims to identify the potential mechanisms by which perivascular adipose tissue (PVAT) reduces tone in small arteries. Small mesenteric arteries from wild-type and large-conductance Ca2+-activated K+ (BKCa) channel knockout mice were mounted on a wire myograph in the presence and absence of PVAT, and contractile responses to norepinephrine were assessed. Electrophysiology studies were performed in isolated vessels to measure changes in membrane potential produced by adiponectin. Contractile responses from wild-type mouse small arteries were significantly reduced in the presence of PVAT. This was not observed in the presence of a BKCa channel inhibitor or with nitric oxide synthase (NOS) inhibition or in BKCa or adiponectin knockout mice. Solution transfer experiments demonstrated the presence of an anticontractile factor released from PVAT. Adiponectin-induced vasorelaxation and hyperpolarization in wild-type arteries were not evident in the absence of or after inhibition of BKCa channels. PVAT from BKCa or adiponectin knockout mice failed to elicit an anticontractile response in wild-type arteries. PVAT releases adiponectin, which is an anticontractile factor. Its effect on vascular tone is mediated by activation of BKCa channels on vascular smooth muscle cells and adipocytes and by endothelial mechanisms.

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