Prostacyclin
Prostacyclin (or PGI2), also known as known as
eicosanoids, a member of the family prostaglandins as a metabolite of
arachidonic acid, inhibits platelet aggregation, and dilates blood
vessels and is released by healthy endothelial cells and performs its
function through a paracrine signaling cascade that involves G
protein-coupled receptors on nearby platelets and endothelial cells(a).
1. Obesity and endothelial dysfunction
Obesity is frequently associated with endothelial dysfunction. In the
study to investigate the role of the 'endothelial' MR in obesity-induced
endothelial dysfunction, the earliest stage in atherogenesis, with
C57BL/6 mice exposed to a normal chow diet (ND) or a high-fat diet
(HFD) alone or in combination with the MR antagonist eplerenone (200
mg/kg/day) for 14 weeks, showed that Obesity-induced endothelial
dysfunction depends on the 'endothelial' mineralocorticoid receptor (MR)
and is mediated by an imbalance of oxidative stress-modulating
mechanisms. Therefore, MR antagonists may represent an attractive
therapeutic strategy in the increasing population of obese patients to
decrease vascular dysfunction and subsequent atherosclerotic
complications(1).
2. Caloric restriction reverses high-fat diet-induced endothelial dysfunction
In the study to examine whether caloric restriction could reverse the
detrimental
vascular effects related to obesity with male C57Bl/6 mice were fed with
normal-fat diet (fat 17%) or high-fat diet (fat 60%) for 150 days. After
establishment of obesity at day 100, a subgroup of obese mice were
put on caloric restriction (CR) (70% of ad libitum energy intake) for
an additional 50 days. At day 100, aortic rings from obese mice
receiving high-fat diet showed impaired endothelium-dependent
vasodilation in response to acetylcholine (ACh), showed that Caloric
restriction markedly attenuated vascular superoxide production.
In obese mice on CR, endothelial denudation increased superoxide
formation whereas vascular superoxide production was unaffected by
L-NAME. Western blot analysis revealed decreased phosphorylated eNOS
(Ser1177)-to-total eNOS expression ratio in obese mice as compared to
lean controls, whereas the phospho-eNOS/NOS ratio in obese mice on CR
did not differ from the lean controls. In conclusion, the present study
suggests that caloric restriction reverses obesity induced endothelial
dysfunction and vascular oxidative stress, and underscores the
importance of uncoupled eNOS in the pathogenesis(2).
3. Prostacyclin receptor (IP-receptor)
agonists anti-inflammatory and antiviral activity
Prostacyclin receptor (IP-receptor)
agonists display anti-inflammatory and antiviral activity in cell-based
assays and in preclinical models of asthma and chronic obstructive
pulmonary disease. In the study to extended these observations by demonstrating that IP-receptor activation also can enhance the ability of glucocorticoids to induce genes with anti-inflammatory activity, found that IP-receptor
agonists can augment the ability of glucocorticoids to induce
anti-inflammatory genes in human airway epithelial cells by activating a
cAMP/PKA-dependent mechanism. This observation may have clinical
relevance in the treatment of airway inflammatory diseases that are
either refractory or respond suboptimally to glucocorticoids(3).
4. Synthesis of prostacyclin effect on the contractile activity of the inflamed porcine uterus
In the study to estimate the content of prostacyclin (PGI(2)), the levels of PGI synthase (PTGIS) and receptor (PTGIR) protein expression,
and the cellular localization of these factors in the
inflammatory-changed porcine uterus, showed that inflammation of the
porcine uterus upregulates PGI(2) synthesis and that
PGI(2) increases contractility, which suggests that PGI(2) might be
essential for the course of uterine inflammation(4).
5. Rosuvastatin and PGI(2)-peroxisome proliferator-activated receptor
Statins are reported to alleviate renal fibrosis in animal models with
ureteral obstruction. Pressure force is an important
mechanism contributing to induction and progression of
tubulointerstitial fibrogenesis in ureteric obstruction. In the study to
assess whether the influence of rosuvastatin on pressure-induced
fibrotic responses in
rat renal tubular cells (NRK-52E). We established an in vitro pressure
culture system to study pressure-induced fibrotic responses in NRK-52E
cells, indicated that rosuvastatin reduces pressure-induced fibrotic
responses in renal
tubular cells by enhancing the PGI(2)-peroxisome proliferator-activated receptor α pathway and reducing PGE(2) generation(5).
6. Prostacyclin and its prostacyclin receptor and cardio-protective
effects
Prostacyclin and its prostacyclin receptor,
the I Prostanoid (IP), play essential roles in regulating hemostasis
and vascular tone and have been implicated in a range cardio-protective
effects. In the study to investigate the influence of cholesterol on human IP [(h)IP] gene expression in cultured vascular endothelial and platelet-progenitor megakaryocytic cells, showed that cholesterol can regulate hIP expression,
which may, at least in part, account for the combined cardio-protective
actions of low serum cholesterol through its regulation of IP expression within the human vasculature(6).
7. Thromboxane A2 and prostacyclin and endothelial dysfunction
Endothelial dysfunction participates in the pathogenesis of many cardiovascular disorders. In the study to assess whether cyclooxygenase-2 (COX-2) activation is involved in the effects of chronic aldosterone treatment on endothelial
function of mesenteric resistance arteries (MRA) from Wistar-Kyoto
(WKY) and spontaneously hypertensive rats (SHR), showed that Aldosterone reduced acetylcholine relaxation in MRA from both strains.
In MRA from both aldosterone-treated strains the COX-1/2 or COX-2
inhibitor (indomethacin and NS-398, respectively), TxA2 synthesis
inhibitor (furegrelate), prostacyclin
synthesis inhibitor (tranylcypromine) or TxA2/ PGH2 receptor antagonist
(SQ 29 548), but not COX-1 inhibitor SC-560, increased acetylcholine
relaxation. In untreated rats this response was increased only in SHR. Prostacyclin
elicited a biphasic vasomotor response: lower concentrations elicited
relaxation, whereas higher concentrations elicited contraction that was
reduced by SQ 29 548. Aldosterone increased the acetylcholine-stimulated
production of 6-oxo-PGF(1alpha) and TxB2 in MRA from both strains.
COX-2 expression was higher in both strains of rats treated with
aldosterone(7).
8. Prostacyclin in endothelial dysfunction
In the study to analyze the possible involvement of vasoconstrictors prostanoids on
the reduced endothelium-dependent relaxations produced by chronic
administration of aldosterone in Wistar Kyoto rats (WKY) and
spontaneously hypertensive rats (SHR), indicated that chronic treatment with aldosterone was able to produce endothelial
dysfunction through COX-2 activation in normotensive and hypertensive
conditions. PGI2 seems to be the main factor accounting for endothelial
dysfunction in hypertensive rats, whereas other prostanoids besides PGI2
appear to be involved in endothelial dysfunction under normotensive
conditions(8).
Chinese Secrets To Fatty Liver And Obesity Reversal
Use The Revolutionary Findings To Achieve
Optimal Health And Loose Weight
Super foods Library, Eat Yourself Healthy With The Best of the Best Nature Has to Offer
Back to Hormones http://kylejnorton.blogspot.ca/p/hormones.html
Back to Kyle J. Norton Home page http://kylejnorton.blogspot.ca
Sources
(a) http://en.wikipedia.org/wiki/Prostacyclin
(1) http://www.ncbi.nlm.nih.gov/pubmed/23594590
(2) http://www.ncbi.nlm.nih.gov/pubmed/20512454
(3) http://www.ncbi.nlm.nih.gov/pubmed/19880449
(4) http://www.ncbi.nlm.nih.gov/pubmed/23218395
(5) http://www.ncbi.nlm.nih.gov/pubmed/23276663
(6) http://www.ncbi.nlm.nih.gov/pubmed/22969152
(7) http://www.ncbi.nlm.nih.gov/pubmed/18500359
(8) http://www.ncbi.nlm.nih.gov/pubmed/15956108
Health Researcher and Article Writer. Expert in Health Benefits of Foods, Herbs, and Phytochemicals. Master in Mathematics & Nutrition and BA in World Literature and Literary criticism. All articles written by Kyle J. Norton are for information & education only.
Pages
- Home
- Kyle J. Norton's Health Tips (948) Alternative Therapy, Whole Foods and Phytochemicals
- @General Health
- @Children Health
- #Women #Health
- My List of Super Foods
- @Phytochemicals In Foods
- Men Health
- Vitamin Therapy
- @Most common Types of Cancer
- Most Common Diseases of Elders
- @Obesity's complications and Weight Loss
- @Healthy Foods Index
- @Popular Chinese Herbs
- Phytochemicals - Cancers and Diseases
- Hormones
- @Popular Herbs
- Dietary Minerals
- 5900+ Health Articles Back By Clinical Trials and Studies
- Food Therapies
- Herbal Therapies
- Phytochemical therapy
- Alternative Therapy(Yoga, Anti Aging and Regular Walking)
- Tons of Recipes
Questions or Enquiries?
Any inquiry of published articles, please e mail kylenorton@hotmail.ca
No comments:
Post a Comment