scholarly journals Intermittent parathyroid hormone administration attenuates endothelial dysfunction in old rats

2017 ◽  
Vol 122 (1) ◽  
pp. 76-81 ◽  
Author(s):  
John J. Guers ◽  
Rhonda D. Prisby ◽  
David G. Edwards ◽  
Shannon Lennon-Edwards
Keyword(s):  
Parathyroid Hormone ◽  
Endothelial Function ◽  
Vascular Dysfunction ◽  
Area Under The Curve ◽  
Enos Expression ◽  
Fischer 344 ◽  
Hormone Administration ◽  
Age Related ◽  
Intermittent Pth ◽  
Aortic Endothelial

Aging is an independent risk factor for cardiovascular disease and is characterized by a decline in endothelial function. Parathyroid hormone (PTH) administration has been shown to increase endothelial nitric oxide synthase (eNOS) expression. The purpose of this investigation was to determine the effect of intermittent PTH administration on aortic endothelial function in old rodents. We hypothesized that intermittent PTH administration would improve endothelial function in older rodents. Old (24-mo-old) and young (4-mo-old) Fischer-344 rats were given 10 injections of PTH 1–34 (43 μg·kg−1·day−1) or phosphate-buffered saline (100 μl/day) over 15 days. Endothelium-dependent relaxation of aortic rings in response to acetylcholine (10−9 to 10−5 M) was significantly impaired in old control (OC) compared with young control (YC) as indicated by a reduced area under the curve (AUC, 100 ± 6.28 vs. 54.08 ± 8.3%; P < 0.05) and impaired maximal relaxation (Emax, 70.1 ± 4.48 vs. 92.9 ± 4.38%; P < 0.05). Emax was improved in old animals treated with PTH (OPTH) (OC, 70.1 ± 4.48 vs. OPTH, 85 ± 7.48%; P < 0.05) as well as AUC (OC, 54.08 ± 8.3 vs. OPTH, 82.5 ± 5.7%; P < 0.05) while logEC50 was not different. Endothelial-independent relaxation in response to sodium nitroprusside was not different among groups. Aortic eNOS protein expression was significantly decreased in OC compared with YC ( P < 0.05). PTH treatment restored eNOS expression in OPTH animals ( P < 0.05). These data suggest that PTH may play a role in attenuating age-related impairments in aortic endothelial function. NEW & NOTEWORTHY We have demonstrated that intermittent parathyroid hormone administration can rescue age-related vascular dysfunction by improving endothelial-dependent dilation in the aorta of older rodents. This demonstrates a novel potential benefit of parathyroid hormone administration in aging.

Abstract T MP114: PPARγ in Endothelial Cells Plays an Essential Role in Protecting Against Vascular Aging: Role of Oxidative Stress and Rho Kinase

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Dale Kinzenbaw ◽  
T. Micheal De Silva ◽  
Curt Sigmund ◽  
Frank M Faraci
Keyword(s):  
Oxidative Stress ◽  
Endothelial Function ◽  
Vascular Disease ◽  
Vascular Dysfunction ◽  
Rho Kinase ◽  
Dominant Negative ◽  
Vascular Aging ◽  
Dominant Negative Mutation ◽  
Age Related

Although aging is the greatest risk factor for vascular disease and stroke, relatively little is known regarding mechanisms that regulate vascular aging. Endothelial dysfunction - a key element of carotid artery and cerebrovascular disease - progresses with age, greatly increasing the risk for ischemic stroke and cognitive impairment. The nuclear receptor peroxisome proliferator activated receptor-γ (PPARγ) is a ligand-activated transcription factor that may exert diverse effects depending on the cell type. Because little is known regarding the role of PPARγ in vascular aging, we used transgenic mice expressing a dominant negative mutation in human PPARγ (V290M) under control of the endothelial-specific vascular cadherin promoter (designated E-V290M) to examine the hypothesis that cell-specific interference with PPARγ would promote age-induced vascular dysfunction. Responses of carotid arteries from adult (11-12 mo) and old (24±1 mo) E-V290M mice and non-transgenic littermates were examined in vitro. Acetylcholine (an endothelium-dependent agonist) produced similar relaxation of arteries from adult control and E-V290M mice as well as old control mice. In contrast, responses to acetylcholine in arteries from old E-V290M mice were reduced by more than 50% in old E-V290M mice (P<0.01). Endothelial function in old E-V290M mice was not altered by indomethacin but was restored to normal by tempol (a superoxide scavenger) or VAS-2870 (an inhibitor of NADPH oxidase). Reactive oxygen species can activate Rho kinase (a potential mediator of vascular disease) and inhibition of Rho kinase with Y-27632 restored endothelial function to normal in old E-V290M mice. Relaxation of arteries to nitroprusside, which acts directly on vascular muscle, was similar in all groups. These findings provide the first evidence that age-related vascular dysfunction is accelerated following cell-specific interference with endothelial PPARγ through mechanisms involving oxidative stress and Rho kinase. This novel role for endothelial PPARγ has implications for understanding vascular pathophysiology as well as therapeutic approaches for age-induced large and small vessel disease.

Vascular and Endothelial Biology of Aging

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. SCI-5-SCI-5
Author(s):  
Frank M. Faraci
Keyword(s):  
Oxidative Stress ◽  
Endothelial Dysfunction ◽  
Transgenic Mice ◽  
Nadph Oxidase ◽  
Endothelial Function ◽  
Vascular Dysfunction ◽  
Rho Kinase ◽  
Vascular Aging ◽  
Age Related ◽  
The Brain

Abstract Although aging is one of the greatest risk factors for vascular disease, very little is known regarding mechanisms that control the progression of vascular aging at the level of the endothelial cell. Endothelial dysfunction - a critical element of carotid artery and cerebrovascular disease - progresses with age, contributing to hypoperfusion, increased risk for ischemic stroke, and cognitive decline. Studies from several laboratories support the concept that age-induced endothelial dysfunction may occur earlier and be larger in magnitude in the cerebral circulation than in blood vessels outside of the brain. Thus, the circulationof the brain may be particularly sensitive to age-induced endothelial dysfunction. In relation to underlying mechanisms, angiotensin II type 1 receptors, NADPH oxidase, and oxidative stress appear to play a key role in age-related vascular dysfunction. The nuclear receptor peroxisome proliferator-activated receptor-g (PPARg) exerts protective effects in the vasculature when pharmacologically activated. We recently examined the hypothesis that endothelial PPARg protects against vascular aging. We studied carotid arteries from adult and old transgenic mice with endothelial specific expression of a human dominant negative mutation in PPARg driven by the vascular cadherin promoter (designated E-V290M), along with non-transgenic littermates. Endothelial function was similar in arteries from adult non-transgenic and E-V290M mice as well as old non-transgenic mice. In contrast, there was a marked reduction in endothelial function in old E-V290M mice. This augmented endothelial dysfunction was not altered by inhibition of cyclooxygenase, but was restored to normal by a superoxide scavenger, an inhibitor of NADPH oxidase, or inhibition of Rho kinase. Oxidant and inflammatory related mechanisms often interact. Vascular expression of interleukin-6, another mediator of vascular disease, was increased 1.6-fold in old non-transgenic mice, but almost 9-fold in old E-V290M mice. Expression of CDKN2A, a molecular marker of senescence, was ~two-fold greater in old E-V290M mice compared to controls. These findings provide the first evidence that senescence and age-related vascular dysfunction is accelerated following cell-specific interference with endothelial PPARg through mechanisms that involve oxidative stress, inflammation, and Rho kinase. This critical role for endothelial PPARg has implications for vascular pathophysiology as well as therapeutic approaches for age-induced large and small vessel disease. Disclosures No relevant conflicts of interest to declare.

Modulation of Age-Related Changes in Serum 1,25-Dihydroxyvitamin D and Parathyroid Hormone by Dietary Restriction of Fischer 344 Rats

1988 ◽  
Vol 118 (11) ◽  
pp. 1360-1365 ◽  
Author(s):  
H. James Armbrecht ◽  
Randy Strong ◽  
Monica Boltz ◽  
David Rocco ◽  
W. Gibson Wood ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Dietary Restriction ◽  
Fischer 344 Rats ◽  
Dihydroxyvitamin D ◽  
Fischer 344 ◽  
1,25 Dihydroxyvitamin D ◽  
Age Related ◽  
Age Related Changes

scholarly journals Aging and exercise training reduce testes microvascular Po2 and alter vasoconstrictor responsiveness in testicular arterioles

2011 ◽  
Vol 301 (3) ◽  
pp. R801-R810 ◽  
Author(s):  
James M. Dominguez ◽  
Robert T. Davis ◽  
Danielle J. McCullough ◽  
John N. Stabley ◽  
Bradley J. Behnke
Keyword(s):  
Exercise Training ◽  
Old Age ◽  
Vascular Dysfunction ◽  
Aerobic Exercise Training ◽  
Testicular Function ◽  
Phosphorescence Quenching ◽  
Fischer 344 ◽  
Age Related

Testicular function and associated testosterone concentration decline with advancing age, and an impaired O2 supply may contribute, in part, to this reduction. We hypothesized that there would be a reduced microvascular Po2 (Po2m) in the testes from aged rats, and this reduced Po2m would be associated with impaired vasomotor control in isolated resistance arterioles. In addition, given the positive effect of exercise on microvascular Po2 and arteriolar function, we further hypothesized that there would be an enhanced Po2m in the testes from aged animals after aerobic exercise training. Testicular Po2m was measured in vivo via phosphorescence quenching in young and aged sedentary (SED) and exercise-trained (ET; 15 m/min treadmill walking, 15-degree incline, 5 days/wk for 10 wk) male Fischer-344 rats. Vasoconstriction to α-adrenergic [norepinephrine (NE) and phenylephrine (PE)] and myogenic stimuli in testicular arterioles was assessed in vitro. In the SED animals, testicular Po2m was reduced by ∼50% with old age (aged SED 11.8 ± 1.9 vs. young SED 22.1 ± 1.1 mmHg; P = 0.0001). Contrary to our hypothesis, exercise training did not alter Po2m in the aged group and reduced testicular Po2m in the young animals, abolishing age-related differences (young ET, 10.0 ± 0.8 vs. aged ET, 10.7 ± 0.9 mmHg; P = 0.37). Vasoconstrictor responsiveness to NE and PE was diminished in aged compared with young (NE: young SED, 58 ± 2 vs. aged SED, 47 ± 2%; P = 0.001) (PE: young SED, 51 ± 3 vs. aged SED, 36 ± 5%; P = 0.008). Exercise training did not alter maximal vasoconstriction to NE in young or aged groups. In summary, advancing age is associated with a reduced testis Po2m and impaired adrenergic vasoconstriction. The diminished testicular microvascular driving pressure of O2 and associated vascular dysfunction provides mechanistic insight into the old age-related decrease in testicular function, and a reduced Po2m may contribute, in part, to reduced fertility markers after exercise training.

scholarly journals Intermittent PTH 1–34 administration improves the marrow microenvironment and endothelium-dependent vasodilation in bone arteries of aged rats

2018 ◽  
Vol 124 (6) ◽  
pp. 1426-1437 ◽  
Author(s):  
Seungyong Lee ◽  
Ashley Bice ◽  
Brianna Hood ◽  
Juan Ruiz ◽  
Jahyun Kim ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Blood Vessels ◽  
Vascular Function ◽  
Dynamic Properties ◽  
Bone Microarchitecture ◽  
Fischer 344 ◽  
Young Rats ◽  
Nutrient Artery ◽  
Old Rats ◽  
Intermittent Pth

Inflammation coincides with diminished marrow function, vasodilation of blood vessels, and bone mass. Intermittent parathyroid hormone (PTH) administration independently improves marrow and vascular function, potentially impacting bone accrual. Currently, the influence of marrow and intermittent PTH administration on aged bone blood vessels has not been examined. Vasodilation of the femoral principal nutrient artery (PNA) was assessed in the presence and absence of marrow. Furthermore, we determined the influence of PTH 1–34 on 1) endothelium-dependent vasodilation and signaling pathways [i.e., nitric oxide (NO) and prostacyclin (PGI2)], 2) endothelium-independent vasodilation, 3) cytokine production by marrow cells, and 4) bone microarchitecture and bone static and dynamic properties. Young (4–6 mo) and old (22–24 mo) male Fischer-344 rats were treated with PTH 1–34 or a vehicle for 2 wk. In the absence and presence of marrow, femoral PNAs were given cumulative doses of acetylcholine, with and without the NO and PGI2blockers, and diethylamine NONOate. Marrow-derived cytokines and bone parameters in the distal femur were assessed. Exposure to marrow diminished endothelium-dependent vasodilation in young rats. Reduced bone volume and NO-mediated vasodilation occurred with old age and were partially reversed with PTH. Additionally, PTH treatment in old rats restored endothelium-dependent vasodilation in the presence of marrow and augmented IL-10, an anti-inflammatory cytokine. Endothelium-independent vasodilation was unaltered, and PTH treatment reduced osteoid surfaces in old rats. In conclusion, the marrow microenvironment reduced vascular function in young rats, and PTH treatment improved the marrow microenvironment and vasodilation with age.NEW & NOTEWORTHY This study investigated the influence of the marrow microenvironment on bone vascular function in young and old rats. An inflamed marrow microenvironment may reduce vasodilator capacity of bone blood vessels, diminishing delivery of blood flow to the skeleton. In young rats, the presence of the marrow reduced vasodilation in the femoral principal nutrient artery (PNA). However, intermittent parathyroid hormone administration (i.e., a treatment for osteoporosis) improved the marrow microenvironment and vasodilator capacity in old PNAs.

scholarly journals Random forest classification for predicting lifespan-extending chemical compounds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia Kapsiani ◽  
Brendan J. Howlin
Keyword(s):  
Caenorhabditis Elegans ◽  
Random Forest ◽  
Molecular Descriptors ◽  
Area Under The Curve ◽  
Chemical Compounds ◽  
Research Area ◽  
Importance Measure ◽  
Random Forest Algorithm ◽  
Molecular Fingerprints ◽  
Age Related

AbstractAgeing is a major risk factor for many conditions including cancer, cardiovascular and neurodegenerative diseases. Pharmaceutical interventions that slow down ageing and delay the onset of age-related diseases are a growing research area. The aim of this study was to build a machine learning model based on the data of the DrugAge database to predict whether a chemical compound will extend the lifespan of Caenorhabditis elegans. Five predictive models were built using the random forest algorithm with molecular fingerprints and/or molecular descriptors as features. The best performing classifier, built using molecular descriptors, achieved an area under the curve score (AUC) of 0.815 for classifying the compounds in the test set. The features of the model were ranked using the Gini importance measure of the random forest algorithm. The top 30 features included descriptors related to atom and bond counts, topological and partial charge properties. The model was applied to predict the class of compounds in an external database, consisting of 1738 small-molecules. The chemical compounds of the screening database with a predictive probability of ≥ 0.80 for increasing the lifespan of Caenorhabditis elegans were broadly separated into (1) flavonoids, (2) fatty acids and conjugates, and (3) organooxygen compounds.

scholarly journals Influence of Intermittent Parathyroid Hormone (PTH) Administration on the Outcomes of Orthodontic Tooth Movement—A Systematic Review

2021 ◽  
Vol 11 (11) ◽  
pp. 5268
Author(s):  
Zohaib Khurshid ◽  
Faris Yahya Asiri
Keyword(s):  
Parathyroid Hormone ◽  
Animal Studies ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Inclusion Criteria ◽  
Medical Subject Headings ◽  
Periodontal Tissues ◽  
Minimal Bias ◽  
Intermittent Pth

Objective: The aim of this review is to summarize the effects of local and systemic PTH administration on periodontal tissues during orthodontic tooth movement. Materials and methods: An electronic search was conducted on the following databases: PubMed/MEDLINE, Google Scholar, SCOPUS and Embase. On PubMed/MEDLINE, the Medical Subject Headings (MeSH) keywords used were: “orthodontic tooth movement” OR (“tooth” (All Fields) AND “tooth movement” (All Fields)) OR “tooth movement” (All Fields)) AND (“parathyroid hormone”); all studies included using CONSORT. Results: After elimination of duplicates and articles not meeting our inclusion criteria, seven animal studies were included in this review. Although the majority of the studies suggest that PTH may a have a favorable outcome on OTM, most studies were found to have several sources of bias. Conclusion: Animal studies with minimal bias and long-term clinical studies are needed to ascertain the efficacy of intermittent PTH administration in improving the rate and retention of OTM.

scholarly journals Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels

2021 ◽  
Vol 22 (3) ◽  
pp. 1296
Author(s):  
Yue Ruan ◽  
Subao Jiang ◽  
Adrian Gericke
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Therapeutic Strategies ◽  
Vision Impairment ◽  
Age Related Macular Degeneration ◽  
Oxygen Species ◽  
Age Related

Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.

scholarly journals Short-term increases in intraluminal pressure reverse age-related decrements in endothelium-dependent dilation in soleus muscle feed arteries

2007 ◽  
Vol 103 (4) ◽  
pp. 1172-1179 ◽  
Author(s):  
Christopher R. Woodman ◽  
Daniel W. Trott ◽  
M. Harold Laughlin
Keyword(s):  
Protein Content ◽  
Soleus Muscle ◽  
Intraluminal Pressure ◽  
Separate Experiment ◽  
Enos Expression ◽  
Short Term ◽  
Age Related ◽  
Enos Mrna ◽  
Feed Arteries ◽  
Increased Pressure

We tested the hypothesis that short-term increases in intraluminal pressure improve endothelium-dependent dilation and increase endothelial nitric oxide (NO) synthase (eNOS) expression in senescent soleus muscle feed arteries (SFA). SFA isolated from young (4 mo) and old (24 mo) Fischer 344 rats were cannulated and pressurized at 90 (p90) or 130 (p130) cmH2O for 4 h. At the end of the 4-h protocol, pressure in p130 SFA was lowered to 90 cmH2O for examination of endothelium-dependent (flow- or ACh-induced) vasodilation. Flow- and ACh-induced dilations were blunted in old p90 SFA relative to young p90 SFA. Pretreatment with increased pressure (p130) improved flow- and ACh-induced dilations in old SFA, such that vasodilator responses were similar to those in young SFA. In the presence of Nω-nitro-l-arginine (l-NNA) or l-NNA + indomethacin (Indo), flow-induced dilation was inhibited in old p130 SFA, such that the response was not greater than the response in old p90 SFA. In old p130 SFA, ACh-induced dilation was inhibited by l-NNA + Indo (not l-NNA alone). In a separate experiment, SFA were pressurized at 70, 90, 110, or 130 cmH2O for 4 h, and eNOS mRNA and protein content were assessed. Increased pressure induced eNOS mRNA expression in young (not old) SFA. eNOS protein content was not altered in young or old SFA. These results indicate that short-term increases in intraluminal pressure improve endothelium-dependent dilation in senescent SFA, in part by enhancing NO bioavailability; however, the beneficial effect was not associated with increased eNOS expression.

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