Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0406810 (NAME)
 13,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelial and vascular smooth muscle cells express both estrogen receptor (ER) alpha and beta. Recent findings indicate that vascular ER beta and ER alpha may substitute for one another. Here, we investigate vascular morphology, contractility and protein expression in intact aorta from adult (4 months old) female mice lacking both ER alpha and ER beta (DERKO). The body weights were 17% higher ( P<0.01) in DERKO than in wild-type mice. Vascular morphology, investigated in paraffin sections from aorta stained with hematoxylin-eosin or van Gieson, was identical in DERKO and wild-type mice. Endothelial cells were clearly visible in aorta of both DERKO and wild-type animals. Morphometric analysis of media thickness and wall to lumen ratio using a computerized image analyzing system demonstrated no differences between the two groups of mice. The vascular expression of endothelial nitric oxide synthase (eNOS, NOS III) and inducible nitric oxide synthase (iNOS, NOS II) was investigated using Western blotting. Aorta from both DERKO and wild-type mice expressed iNOS protein, but the iNOS expression was 3 times lower ( P<0.05) in DERKO compared to wild-type mice. No difference in eNOS protein level between the two groups of animals was observed. Force responses to noradrenaline, determined either in the absence or in the presence of the nitric oxide synthase inhibitor l-NAME and the cyclo-oxygenase inhibitor indomethacin, were unaffected by the lack of functional ER alpha/ER beta. In summary, combined lack of functional ER alpha and ER beta lowers the vascular expression of iNOS but has no effects on morphology, eNOS expression, and noradrenaline sensitivity in the intact aorta.
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PMID:Combined lack of estrogen receptors alpha and beta affects vascular iNOS protein expression. 1282 94

This study was designed to test the hypothesis that endogenous estrogens decrease the expression of endothelial nitric oxide synthase (eNOS) in resistance-size bone arterioles, thereby reducing endothelium-dependent vasodilator function. Sexually mature female rats were ovariectomized to reduce endogenous estrogens. Age-matched female rats served as controls. Seven to ten days after ovariectomy, bone marrow tissue was collected from the femoral canal. Immuno-histochemistry was performed to detect expression of estrogen receptors, alpha and beta and eNOS. eNOS protein content in medullary bone arterioles was compared using Western blot analysis. Endothelial cell function was assessed by quantitating the dilation of isolated, pressurized bone arterioles in response to acetylcholine. The results indicate that the endothelium of bone arterioles from ovariectomized and control rats express ER-alpha, ER-beta and eNOS. eNOS protein content in the two groups of arterioles did not differ. However, the baseline diameter of arterioles from ovariectomized rats (63+/-4 microm) was significantly smaller than the diameter of arterioles from control rats (75+/-3 microm, p<0.05). The two groups of arterioles dilated equally in response to acetylcholine. L-NAME, an inhibitor of eNOS, almost completely abolished the dilator responses to acetylcholine, but not to sodium nitroprusside. L-Arginine restored acetylcholine-induced dilation after L-NAME treatment. Thus, arteriole dilation to acetylcholine appears to be mediated almost exclusively by NO. The smaller diameter of arterioles from ovariectomized rats suggests that endogenous estrogens exert a significant dilator influence on bone arterioles. However, the dilator influence does not appear to be mediated by an increase in eNOS expression or enhanced NO-dependent vasodilation. These results indicate that estrogens do not decrease eNOS expression or diminish NO-mediated dilation of bone medullary arterioles.
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PMID:Bone medullary arterioles from ovariectomized rats have smaller baseline diameters but normal eNOS expression and NO-mediated dilation. 1601 34

The objectives of this study were to determine whether acute dilatory responses to estrogen receptor agonists are altered in isolated arteries from estrogen receptor beta-deficient mice (beta-ERKO) and to gain insight into the role of nitric oxide (NO) in these responses. Femoral arteries (approximately 250 microm) from male and female beta-ERKO mice and wild-type (WT) littermates (26 female, 13 in each group; and 24 male, 12 in each group) were mounted on a Multi-Myograph. Concentration-response curves to 17beta-estradiol (17beta-E2) and the selective estrogen receptor-alpha (ER-alpha) agonist propyl-[1H]-pyrazole-1,3,5-triy-trisphenol (PPT) were obtained before and after NO synthase (NOS) inhibition [Nomega-nitro-L-arginine methyl ester (L-NAME), 0.1 mM] in arteries preconstricted with U-46619 (a thromboxane analog). In WT mice, responses to the potent estrogen receptor-beta (ER-beta) agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) and the contribution of NO were also assessed. Concentration-response curves to 17beta-E2 and PPT were similar in arteries from WT and -ERKO mice of both genders, but NO-mediated relaxation was different, since L-NAME reduced 17-E2 mediated relaxation in arteries from male and female beta-ERKO but not WT mice (P < 0.05). NOS inhibition reduced dilation to PPT in arteries from male and female WT mice, as well as arteries from female beta-ERKO mice (P < 0.05). Responses to DPN in arteries from WT female and male mice did not differ after NOS inhibition. The acute dilatory responses to estrogenic compounds are similar in WT and beta-ERKO mice but differ mechanistically. Because NO appeared to contribute to responses to 17beta-E2 in arteries from beta-ERKO but not WT mice, the presence of ER- apparently inhibits ER--mediated NO relaxation.
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PMID:Dilatory responses to estrogenic compounds in small femoral arteries of male and female estrogen receptor-beta knockout mice. 1618 27

Both endogenous and exogenous estrogen decrease pulmonary artery (PA) vasoconstriction. Whether these effects are mediated via estrogen receptor (ER)-alpha or ER-beta, and whether the contribution of ERs is stimulus-dependent, remains unknown. We hypothesized that administration of the selective ER-alpha agonist propylpyrazole triol (PPT) and/or the selective ER-beta agonist diarylpropiolnitrile (DPN) rapidly decreases PA vasoconstriction induced by pharmacologic and hypoxic stimuli via a nitric oxide (NO)-dependent mechanism. PA rings (n = 3-10/group) from adult male Sprague-Dawley rats were suspended in physiologic organ baths. Force displacement was measured. Vasoconstrictor responses to phenylephrine (10(-8)M - 10(-5)M) and hypoxia (Po(2) 35-45 mmHg) were determined. Endothelium-dependent and -independent vasorelaxation were measured by generating dose-response curves to acetylcholine (10(-8)M - 10(-4)M) and sodium nitroprusside (10(-9)M - 10(-5)M). PPT or DPN (10(-9)M - 5 x 10(-5)M) were added to the organ bath in the presence and absence of the NO-synthase inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME) (10(-4)M). Selective ER-alpha activation (PPT, 5 x 10(-5)M) rapidly (<20 min) decreased phenylephrine-induced vasoconstriction. This effect, as well as PPT's effects on endothelium-dependent vasorelaxation, were neutralized by l-NAME. In contrast, selective ER-beta activation (DPN, 5 x 10(-5)M) rapidly decreased phase II of hypoxic pulmonary vasoconstriction (HPV). l-NAME eliminated this phenomenon. Lower PPT or DPN concentrations were less effective. We conclude that both ER-alpha and ER-beta decrease PA vasoconstriction. The immediate onset of effect suggests a nongenomic mechanism. The contribution of specific ERs appears to be stimulus specific, with ER-alpha primarily modulating phenylephrine-induced vasoconstriction, and ER-beta inhibiting HPV. NO inhibition eliminates these effects, suggesting a central role for NO in mediating the pulmonary vascular effects of both ER-alpha and ER-beta.
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PMID:Selective estrogen receptor-alpha and estrogen receptor-beta agonists rapidly decrease pulmonary artery vasoconstriction by a nitric oxide-dependent mechanism. 1883 85

We evaluated the vasorelaxation effects of formononetin, an isoflavone/phytoestrogen found abundantly in Astragalus mongholicus Bunge, on rat isolated aorta and the underlying mechanisms involved. Cumulative administration of formononetin, genistein, daidzein and biochanin A relaxed phenylephrine-preconstricted aorta. Formononetin and biochanin A caused a similar magnitude of relaxation whereas daidzein was least potent. Mechanical removal of endothelium, L-NAME (100 microM) and methylene blue (10 microM) suppressed formononetin-induced relaxation. Formononetin increased endothelial nitric oxide (NO) synthase (eNOS), but not inducible NO synthase, activity with an up-regulation of eNOS mRNA and p-eNOS(Ser1177) protein expression. In endothelium-denuded preparations, formononetin-induced vasorelaxation was significantly reduced by glibenclamide (3 microM) and iberiotoxin (100 nM), and a combination of glibenclamide (3 microM) plus iberiotoxin (100 nM) abolished the relaxation. In contrast, formononetin-elicited endothelium-independent relaxation was not altered by ICI 182,780 (10 microM, an estrogen receptor (ER alpha/ER beta) antagonist) or mifepristone (10 microM, a progesterone receptor antagonist). In single aortic smooth muscle cells, formononetin caused opening of iberiotoxin-sensitive Ca(2+)-activated K(+) (BK(Ca)) channels and glibenclamide-sensitive adenosine triphosphate (ATP)-dependent K(+) (K(ATP)) channels. Thus, our results suggest that formononetin caused vascular relaxation via endothelium/NO-dependent mechanism and endothelium-independent mechanism which involves the activation of BK(Ca) and K(ATP) channels.
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PMID:Formononetin, an isoflavone, relaxes rat isolated aorta through endothelium-dependent and endothelium-independent pathways. 1957 Jun 71

The aim of present study was to investigate the changes in the testicular expression of aromatase, ER alpha, ER beta and iNOS protein and correlate these with serum testosterone and nitric oxide levels, to elucidate the role of estrogen and nitric oxide in the testis during aging. This study showed localization of aromatase and ER alpha mainly in the Leydig cell and showed close correlation of testicular aromatase level with circulating testosterone level suggesting that estrogen may be modulating testicular steroidogenesis. Localization ER alpha mainly in the mitotically active germ cell suggest possible role of estrogen in germ cell proliferation. This study showed basal level of nitric oxide during reproductively active period, whereas increased serum nitric oxide coincides with decreased testicular activity in old age. This study showed inverse correlation between aromatase and NO level. Treatment with either SNP or L-NAME on testicular steroidogenic factor (3-beta HSD/ StAR) or germ cell survival factor (Bcl2) showed that increased NO causes decreased steroidogenesis and increased germ cell apoptosis. In conclusion this study suggest that estrogen modulate steroidogenesis and germ cell survival in reproductively active period whereas in old age decreased estrogen concentration causes increased nitric oxide which in turn decreases testicular steroidogenesis and germ cell apoptosis.
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PMID:Alteration in expression of estrogen receptor isoforms alpha and beta, and aromatase in the testis and its relation with changes in nitric oxide during aging in mice. 2236 72