Takuzo Hano

Wakayama Medical University, Wakayama, Wakayama, Japan

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Publications (138)238.09 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Pupillometry was used to evaluate the effects of the calcium channel blockers cilnidipine (CL) and amlodipine (AM) on changes in autonomic nervous activity induced by isometric exercise in patients with hypertension. After handgrip exercise, the velocity of miosis increased in both the CL and AM groups. However, the velocity of mydriasis increased in only the AM group. Velocity slopes of miosis and mydriasis were smaller in the CL group than in the AM group. The low-to-high frequency ratio obtained from pulse wave analysis increased in only the AM group. Sympathetic activation elicited by isometric exercise was suppressed more effectively by CL than by AM.
    Clinical and Experimental Hypertension 05/2015; DOI:10.3109/10641963.2015.1025959 · 1.46 Impact Factor
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    ABSTRACT: Abstract Stimulation of µ1-opioid receptors (M1ORs) in the medial nucleus solitarius (mNTS) by endomorphin-2 (EM2) elicits decreases in mean arterial pressure (MAP), heart rate (HR) and greater splanchnic nerve activity (GSNA) in Wistar rats. We tested the hypothesis that EM2-induced responses in the mNTS may be attenuated in the spontaneously hypertensive rat (SHR). Experiments were carried out in urethane-anesthetized, artificially ventilated, adult male SHR and Wistar-Kyoto rats (WKY). Alterations in responses to chemical stimulation of the hypothalamic arcuate nucleus (ARCN) after bilateral blockade of M1ORs in the mNTS were also studied. In SHR, microinjections of EM2 into the mNTS elicited smaller decreases in MAP, HR and GSNA compared to those elicited in WKY; smaller cardiovascular responses in SHR can be explained by lower expression of M1OR mRNA in the NTS of SHR compared to WKY. Decreases in MAP and GSNA and increases in HR were elicited by microinjections of N-methyl-d-aspartic acid (NMDA) into the ARCN of WKY. Bilateral blockade of M1ORs in the mNTS attenuated the decreases in MAP and GSNA and exaggerated the increases in HR elicited by the ARCN stimulation in WKY but not in SHR. Tonic inhibitory activity of neuropeptide Y/gamma-aminobutyric acid (NPY/GABA) neurons in the ARCN is attenuated in SHR; this observation may explain increases in MAP, GSNA and HR elicited by microinjections of NMDA into the ARCN of SHR. These results demonstrate that attenuation of EM2-induced responses in the mNTS of SHR may contribute to the excitatory responses elicited by ARCN stimulation in SHR.
    Clinical and Experimental Hypertension 07/2014; DOI:10.3109/10641963.2014.933969 · 1.46 Impact Factor
  • Health 01/2014; 06(21):2999-3004. DOI:10.4236/health.2014.621337 · 0.51 Impact Factor
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    ABSTRACT: Objectives: Function test of pupil is available for evaluation of sympathetic and parasympathetic activity. In the present study, effects of L/N type of calcium channel blocker, cilnidipine on hemodynamic and autonomic changes during isometric exercise were tested using pupil function test in hypertensive patients. Methods: Hypertensive patients treated with cilnidipine (CL, n=19) or amlodipine (AM, n=18) as control enrolled in this study. Blood pressure, pulse rate, velocity of miosis and mydriasis by light stimulation were measured before and after hand-grip exercise by 70% of maximal grasp power. Results: Blood pressure in CL and AM were elevated by hand grip exercise from 136.6+/-18.2mmHg and 143.3+/-10.0mmHg to 151.8+/-15.3mmHg, 150.6+/-9.3mmHg, respectively. Pulse rate was increased from 67.4+/-6.8/min. to 75.7+/-11.9/min by handgrip exercise in CL and from 68.5+/-10.4/min to 73.2+/-12/min in AM. There were no differences of blood pressure and pulse rate in both groups. Velocity of miosis by light stimulation was increased significantly by hand-grip test both in AM and CL (AM: at rest 3.7+/-0.3ms, after exercise 4.7+/-0.5ms, p=0.02, CL: at rest; 3.5+/-0.2ms, after exercise; 3.8+/-0.3ms, p=0.03). Velocity of miosis in CL was smaller than that in AM (p=0.04). Velocity of midriasis after light stimulation in AM (1.9+/-0.2ms at rest) was significantly increased after exercise (2.7+/-0.2ms, p=0.002). In contrast to AM, velocity of midriasis in CL (1.7+/-0.1ms at rest) was no difference from that after exercise (1.7+/-0.1ms). Conclusions: CL suppressed autonomic activation by handgrip exercise. Inhibitory effect of CL on sympathetic activation was more marked than that on parasympathetic activation.
    Journal of Hypertension 01/2012; 30:e63-e64. DOI:10.1097/01.hjh.0000420037.66026.a8 · 4.22 Impact Factor
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    ABSTRACT: Objectives: Improvement of drug adherence is useful to achieve the goal of hypertension therapy. Usefulness of combined drug for the achievement rate of goal is unclear in Japan popularized healthy insurance. In the present study, combination drugs were changed to combined drug of calcium channel blockade (Ca) and angiotensin II receptor antagonist (ARB) in patients treated with combination of Ca and ARB. Methods: One hundred and nine hypertensive patients treated with combination therapy of Ca and ARB were enrolled in this study. Drugs were changed to combined drug of Ca and ARB and drug adherence, blood pressure changes were survey before, 4 and 8 weeks after change of drugs. Mean age of enrolled patients was 66.7 years and average number of drugs was 4.6 +/- 2.3. Drug adherence was classified to good, fair, poor. Good and fair was 94.1% and 4.7%, respectively. Systolic and diastolic blood pressure was 146.8 +/- 17.8 and 72.7 +/- 10.7mmHg before change of drugs. After change to combined drug, improvement, slight improvement and no improvement of drug adherence were 12.5%, 56.3% and 25%, respectively. Reduction and no change of drug payment were 37.5% and 62.5% in attitude survey. Drug payment was actually reduced by 73.3 yen per day. Systolic and diastolic blood pressure were 138 +/- 15.5/71.4 +/- 10.7mmHg 4 weeks after change and 136.3 +/- 5.1/71.2 +/- 9.3mmH 8 week after change of drugs (p < 0.001 vs. control period). Conclusions: Attitude survey showed that patients overestimate their drug adherence. Change of combination drugs to combined drug improves drug adherence and blood pressure control in Japanese population.
    Journal of Hypertension 01/2012; 30:e162. DOI:10.1097/01.hjh.0000420823.48472.c0 · 4.22 Impact Factor
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    ABSTRACT: Background: The arterial stiffness predicts a higher risk of atherosclerosis. However, the association of arterial stiffness and coronary plaque morphology remains unclear. Optical coherence tomography (OCT) can reveal coronary plaque morphology in detail. In this study, we evaluated the association of carotid arterial stiffness and coronary plaque characteristics assessed by OCT. Methods: Thirty-five patients with angina pectoris were enrolled. Augmentation index (AI), stiffness parameter [beta], and pulse wave velocity (PWV) were measured by carotid ultrasound. At the coronary culprit artery, plaque characterization (lipid, or fibrous plaque), calcification, fibrous cap thickness (FCT), thin cap fibroatheroma (TCFA), and plaque rupture (PR) were analyzed by OCT. Results: Stiffness parameter [beta] and PWV were greater in patients with fibrous plaque than in patients with lipid plaque (stiffness parameter [beta] 12.4 [10.3-15.1] vs. 9.4 [7.9-10.9], p = 0.009; PWV 7.3 [6.9-8.7] m/s vs. 6.9 [5.9-7.4] m/s, p = 0.044). However, there was no significant difference in AI. Stiffness parameter [beta] was correlated with maximum FCT (r = 0.516, p = 0.012) and the number of calcification (r=0.436, p = 0.016). Moreover, stiffness parameter [beta] was greater in patients without TCFA or PR than in patients with TCFA or PR (TCFA (-) 12.4 [9.6-15.7] vs. TCFA (+) 10.1 [7.9-12.0], p = 0.026; PR (-) 19.7 [12.5-26.9] vs. PR (+) 11.1 [6.2-18.8], p = 0.026). Conclusions: Carotid arterial stiffness was associated with the characteristics of coronary culprit lesion morphology. Especially, higher stiffness parameter [beta] may indicate the presence of coronary fibrous plaque with lower vulnerability.
    Journal of Hypertension 01/2012; 30:e45. DOI:10.1097/01.hjh.0000419971.15409.c2 · 4.22 Impact Factor
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    ABSTRACT: Objectives: To clarify the difference of autonomic responses in treated hypertensive patients who showed same hemodynamic response as control, pupil function was tested before and after isometric hand-grip exercise. Methods: Ten healthy volunteers (NT) and 20 hypertensive patients treated with calcium antagonist, amlodipine (HT) were enrolled in this study. Blood pressure, heart rate, pupil function as parameter of autonomic activity, vascular stiffness using waveform index and LF/HF were measured before and after hand-grip exercise by 70% of maximal load. Results: Systolic blood pressure of NT (113.9.6 +/- 14.7mmHg, mean +/- SD) mmHg was higher than that of HT (133.3 +/- 11.2mmHg) before exercise. Blood pressure and heart rate were elevated after hand-grip exercise in both groups. Velocity of pupil contraction (VC) by red light stimulation in NT showed no significant changes from 3.4 +/- 0.9ms to 3.4 +/- 1.1ms. In contrast, those in HT were increased significantly from 3.5 +/- 1.2ms to 4.6 +/- 1.9ms. Velocity of pupil dilatation (VD) in NT changed from 2.2 +/- 1.1ms to 2.2 +/- 1.1ms by exercise, and those in HT were increased form 1.8 +/- 0.7ms to 2.7 +/- 1.0ms. Vascular stiffness was increased in NT (p = 0.02) but not in HT. FFT LF/HF in NT showed no change by exercise but that in HT was elevated significantly by exercise (p = 0.09). Conclusions: Responses of blood pressure and heart rate in NT were similar to those in HT. However increment of sympathetic tone was enhanced in hypertensive patients treated with calcium antagonist in comparison with healthy subjects.
    Journal of Hypertension 01/2012; 30:e145. DOI:10.1097/01.hjh.0000420343.41604.92 · 4.22 Impact Factor
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    ABSTRACT: We investigated cardiac and vascular gene profiles in response to immobilization stress (IMO) in rats, an animal model of emotional stress-induced takotsubo cardiomyopathy using microarray analysis, followed by re-confirmation with real-time reverse transcription-polymerase chain reaction. Expression levels of the identified genes were further estimated by pretreatment with an α1-adrenoceptor blocker and/or a β1-adrenoceptor blocker. In response to IMO, expression of 46 genes was significantly altered in the heart and that of 49 genes was significantly altered in the aorta. Pathway analysis with DAVID Bioinformatics Resources indicated that regulation of transcription and response to endogenous stimulation were the top two scoring pathways. Altered expression of cardiac genes was blunted by pretreatment with a β1-adrenoceptor blocker or α1 + β1-adrenoceptor blockers. In contrast, that of aortic genes was blunted by pretreatment with an α1-adrenoceptor blocker or α1 + β1-adrenoceptor blockers. Activation of α1-adrenoceptor in the blood vessels or activation of β1-adrenoceptors in the heart were mainly responsible for emotional stress-induced alteration of cardiac and vascular gene profiles.
    Heart and Vessels 12/2010; 26(3):321-37. DOI:10.1007/s00380-010-0070-8 · 2.11 Impact Factor
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    ABSTRACT: Disturbance of the coronary microcirculation and catecholamine intoxication, which may be responsible for the pathogenesis of takotsubo cardiomyopathy, could trigger an oxidative stress response in the heart. Expression and localization of inducible heme oxygenase-1 (HO-1), which is an oxidative stress-related factor in the heart of immobilization stressed (IMO) rats, an animal model of takotsubo cardiomyopathy, were investigated by real-time reverse transcriptase-polymerase chain reaction and in situ hybridization histochemistry and immunohistochemistry. In response to IMO, the levels of HO-1 mRNA in the heart and in the aorta were slightly increased at 90 min, and increased 3-fold at 3 h compared with control levels. The signals for HO-1 mRNA were expressed on scatted cells in the myocardium and aortic adventitia. Double fluorescence immunohistochemistry showed that HO-1 immunoreactive cells were also ED1 and ED2 positive, indicating that they were macrophages. The numbers of ED1 and ED2 positive cells were constant, whereas the number of HO-1 positive cells was increased 5-fold at 6 h compared with control levels. Blocking of alpha- and beta-adrenoceptors attenuated IMO-induced upregulation of HO-1 mRNA levels in the heart. Emotional stress and a surge of catecholamine upregulate HO-1 in the cardiac and aortic macrophages.
    Circulation Journal 05/2009; 73(6):1141-6. DOI:10.1253/circj.CJ-08-0988 · 3.69 Impact Factor
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    ABSTRACT: To investigate the effect of taurine on the sympathetic nervous system, I observed pressor responses of perfused mesenteric arteries by electrical stimulation and baro-reflex sensitivity of spontaneously hypertensive rats (SHR/Izm) and control Wistar-Kyoto rats (WKY/Izm) treated with taurine. Taurine added to the perfusate suppressed norepinephrine (NE) overflow and the pressor response mediated by electrical stimulation of isolated perfused mesenteric arteries. Taurine showed a greater suppressive effect on NE overflow and the pressor response mediated by electrical stimulation in SHR/Izm rats than in WKY/Izm rats. Increment of renal sympathetic nerve activity induced by jet-air stress was suppressed in SHR/Izm rats treated with 3% taurine. The arterial baro-reflex sensitivity was more sensitive in SHR/Izm rats treated with taurine than in those exposed to no taurine. These data suggest that taurine lowers blood pressure directly via the suppression of NE release from the peripheral sympathetic nerve and the improvement of impaired baro-reflex sensitivity.
    Advances in Experimental Medicine and Biology 02/2009; 643:57-63. DOI:10.1007/978-0-387-75681-3_6 · 2.01 Impact Factor
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    ABSTRACT: Emotional stress triggers takotsubo cardiomyopathy in postmenopausal women. Clinical analysis of autonomic nervous function has revealed a transient increase of sympathetic nervous activity and decrease of vagal nervous activity. Immobilization (IMO) stress of rats can reproduce the electrocardiographic and left ventriculographic changes that occur in takotsubo cardiomyopathy, both of which are prevented by combined blockade of alpha- and beta-adrenoceptors. Estrogen supplementation partially attenuated these cardiac changes. It also attenuated the IMO-induced increase of c-Fos immunoreactivity, or c-fos mRNA expression in the lateral septum, medial amygdaloid nucleus, paraventricular hypothalamic nucleus, dorsomedial hypothalamic nucleus, laterodorsal tegmental nucleus, and locus ceruleus; these regions contain central sympathetic neurons and neurons with immunoreactive estrogen receptors. It also downregulated c-fos mRNA expression in the adrenal gland and the heart, suggesting an increase of estrogen attenuated the stress-induced hypothalamo-sympathoadrenal outflow from the central nervous system to the target organs. Estrogen treatment also upregulated the levels of cardioprotective substances, such as atrial natriuretic peptide and heat shock protein 70, in the heart. These data suggest that reduction of estrogen levels following menopause might be involved in the primary cause of takotsubo cardiomyopathy both by indirect action on the nervous system and by direct action on the heart.
    Annals of the New York Academy of Sciences 01/2009; 1148(1):479-85. DOI:10.1196/annals.1410.079 · 4.31 Impact Factor
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    ABSTRACT: Unlike arteriogenesis, little is known about the effects of vasculogenesis and its major effector cells, endothelial progenitor cells (EPCs) on collateral formation. In this study, we investigated whether or not the number and function of EPCs were associated with the development of collateral formation in patients with single-vessel coronary artery disease of chronic total occlusion (CTO). The subjects were patients (n=35) undergoing coronary angiography (CAG) who had CTO in one major coronary artery. EPCs were isolated from peripheral blood samples and cultured. Their phenotypes were confirmed by uptake of acetylated LDL and binding of fluorescein isothiocyanate (FITC)-labeled Ulex europaeus agglutinin 1 (UEA-1) lectin. The numbers of colony-forming units (CFUs) and the senescent cells, determined by acidic beta-galactosidase staining, were counted. The angiogenic growth factors from the culture medium were also measured by ELISA. Patients with good collaterals (n=22, Rentrop class 2 and 3) exhibited an increased number of CFUs (p=0.023), reduced number of senescent cells (p=0.010), and higher concentration of b-FGF (0.036) in the culture medium, compared with subjects with poor collaterals (n=13, Rentrop class 0 and 1). Our findings suggested that EPC-mediated angiogenesis might be associated with coronary collateral formation in humans.
    Internal Medicine 02/2008; 47(3):127-34. DOI:10.2169/internalmedicine.47.0284 · 0.97 Impact Factor
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    ABSTRACT: Takotsubo cardiomyopathy is triggered by emotional or physical stress especially in post-menopausal women. A reduction in estrogen levels following menopause might underlie the high incidence of takotsubo cardiomyopathy. The left ventricular contraction between ovariectomized rats (OVX) and OVX with estrogen supplementation (OVX + E) while subjected to immobilization stress (IMO) was compared. The IMO in combination with general anesthesia impaired the left ventricular contraction in both OVX and OVX + E. Estrogen supplementation tended to improve the IMO-induced cardiac dysfunction and significantly attenuated the increase of blood pressure and heart rate. To understand the protective mechanism of estrogen, the expression of c-fos mRNA, a marker of cellular activation was compared. The mRNA expression of cardioprotective substances in the heart was also investigated. In the OVX + E, the levels of c-fos mRNA were significantly decreased in the paraventricular hypothalamic nucleus, adrenal gland and left ventricle, suggesting that an increase of estrogen attenuates the emotional stress-induced hypothalamo-sympatho-adrenal outflow from the central nervous system to the target organs. An expression of heat shock protein 70 and atrial natriuretic peptide was significantly augmented in the OVX + E. These data suggest that estrogen supplementation partially prevents emotional stress-induced cardiovascular responses both by indirect action on the nervous system and by direct action on the heart.
    Circulation Journal 05/2007; 71(4):565-73. DOI:10.1253/circj.71.565 · 3.69 Impact Factor
  • Takuzo Hano
    Nippon rinsho. Japanese journal of clinical medicine 03/2006; 64 Suppl 2:252-6.
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    ABSTRACT: Restenosis after stent implantation is caused by endothelial cell damage and subsequent neointimal formation. The objective of this study is to elucidate the relevance of endothelial progenitor cells (EPCs) in the development of in-stent restenosis in patients undergoing stent implantation. The subjects were 46 patients who underwent coronary stenting. Blood samples were collected at the time of follow-up coronary angiography after coronary stenting. EPCs were isolated from blood samples and cultured. Their phenotypes were confirmed by uptake of acetylated low-density lipoprotein and binding of fluorescein isothiocyanate-labeled Ulex europaeus agglutinin 1 lectin. The number of colony-forming units (CFUs) and the senescent cells, determined by acidic beta-galactosidase staining, was counted. Angiogenic growth factors secreted by EPCs, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), hepatocyte growth factor (HGF), and macrophage chemoattractant protein (MCP-1) from the culture medium were also measured by enzyme-linked immunosorbent assay. Patients with in-stent restenosis (defined as >40% stenosis, n=16) had a decreased number of CFUs (p<0.05), and increased senescent cells (p<0.05), compared to patients without restenosis (n=30). There was no significant difference of angiogenic growth factors (VEGF, HGF, b-FGF, and MCP-1) secreted by EPCs between the two groups. On multivariate analysis, an increased number of senescent EPCs was the indepen-dent factor associated with in-stent restenosis (OR 1.10, 95% CI 1.01 to 1.20). These data suggested that EPCs might be involved in the development of in-stent restenosis.
    Internal Medicine 01/2006; 45(9):581-7. DOI:10.2169/internalmedicine.45.1663 · 0.97 Impact Factor
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    ABSTRACT: Recent studies have revealed an association between coronary risk factors and both the number and function of bone marrow-derived endothelial progenitor cells (EPCs). Although hypertension is an important coronary risk factor, the influence to the EPCs is not fully understood. We investigated the effect of hypertension on EPC senescence. Experimental study We investigated the number and senescence of EPCs in spontaneously hypertensive rats (SHR/Izm) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. EPCs were isolated from peripheral blood of rats and were characterized. EPC senescence was detected by acidic beta-galactosidase staining. In addition, we measured the telomerase activity using polymerase chain reaction-enzyme-linked immunosorbent assay. CLINICAL STUDY: EPCs were isolated from peripheral blood samples in 37 patients with essential hypertension. After ex-vivo cultivation, we detected senescence and measured the telomerase activity. The total severity index of hypertension-induced organ damage was calculated by the summation of each severity index in the classification of hypertension severity by Tokyo University (1984). Experimental study The EPC senescence in SHR/Izm and DOCA-salt hypertensive rats was significantly increased compared with that of control rats. The telomerase activities in SHR/Izm and DOCA-salt hypertensive sensitive rats were also significantly lowered compared with those of control rats. Clinical study Compared with the control group, EPCs from hypertensive patients showed accelerated senescence and also showed reduced telomerase activity. In hypertensive patients, the degree of hypertension-induced organ damage was negatively correlated with telomerase activity, and was positively correlated with EPC senescence. EPC senescence is accelerated in both experimental hypertensive rats and patients with essential hypertension, which may be related to telomerase inactivation. The hypertension-induced EPC senescence may affect the process of vascular remodeling.
    Journal of Hypertension 11/2005; 23(10):1831-7. DOI:10.1097/01.hjh.0000183524.73746.1b · 4.22 Impact Factor
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    ABSTRACT: The functional impairment associated with atherogenic factors, including hypertension, constitutes a limitation to the ability of endothelial progenitor cells (EPCs) to repair. In addition, estrogens have been shown to play a role in reendothelialization after vascular injury. We investigated the effects of estrogens on differentiation and senescence of EPCs derived from bone marrow (BM-EPCs) in spontaneously hypertensive rats (SHR/Izm). Bone marrow (BM) cells were obtained from the tibias and femurs of age-matched, male SHR/Izm and Wistar-Kyoto rats (WKY/Izm). The number of differentiated, adherent BM-EPCs derived from SHR/Izm was significantly smaller than the number derived from WKY/Izm. 17beta-Estradiol (E2) significantly increased the number of adherent BM-EPCs from SHR/Izm, and this effect was significantly attenuated by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers. Immunoblotting analysis revealed that E2 treatment led to phosphorylation of Akt. Senescence, as assessed by acidic beta-galactosidase staining, occurred at a significantly greater rate in the BM-EPCs from SHR/Izm than in those from WKY/Izm, but E2 treatment dramatically delayed the senescence of BM-EPCs from SHR/Izm. A polymerase chain reaction (PCR)-ELISA based assay revealed that telomerase activity in BM-EPCs from SHR/Izm was significantly lower than in those from WKY/Izm, but that E2 treatment significantly augmented it. Both MTS and colony forming unit assay revealed that E2 treatment significantly augmented the functional activity in BM-endothelial cell (EC)-like cells from SHR/Izm compared to that in control BM-EC-like cells (no treatment). In conclusion, the differentiation of BM-EPCs derived from SHR/Izm was significantly decreased compared with that of BM-EPCs from WKY/Izm. In addition, the rate of senescence was significantly greater in the BM-EPCs from SHR/Izm than in those from WKY/Izm. Estrogen was shown to augment differentiation and delay the onset of senescence in BM-EPCs from SHR/Izm.
    Hypertension Research 10/2005; 28(9):763-72. DOI:10.1291/hypres.28.763 · 2.94 Impact Factor
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    ABSTRACT: Recent studies have demonstrated that aging or senescence constitutes a potential limitation to the ability of endothelial progenitor cells (EPCs) to sustain ischemic tissue and repair. Conversely, estrogens have been shown to accelerate recovery of the endothelium after vascular injury. To investigate whether estrogens are able to prevent senescence of EPCs. Human EPCs were isolated from peripheral blood and characterized. After ex-vivo cultivation, the cells became senescent as determined by acidic beta-galactosidase staining. 17beta-estradiol dose-dependently inhibited the onset of EPC senescence in culture. Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity using a polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA) technique. 17beta-estradiol significantly increased telomerase activity. Interestingly, reverse transcriptase-PCR analysis demonstrated that 17beta-estradiol dose-dependently increased the catalytic subunit, telomerase reverse transcriptase (TERT) - an effect that was significantly inhibited by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers (either wortmannin or LY294002). Because the expression of TERT is regulated by the PI3-K/Akt pathway, we examined the effect of 17beta-estradiol on Akt activity in EPCs. Immunoblotting analysis revealed that 17beta-estradiol dose-dependently led to phosphorylation and, thus, to activation of Akt in EPCs. We also examined whether the protective effect of 17beta-estradiol on EPC senescence translates into the augmentation of mitogenic activity in EPCs. A [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay demonstrated that the mitogenic potential in EPCs treated with 17beta-estradiol exceeded that in untreated (control) EPCs (P < 0.01). In addition, EPCs released vascular endothelial growth factor (VEGF) protein--an effect that was significantly augmented by 17beta-estradiol. Finally, in a Matrigel assay, EPCs treated with both 17beta-estradiol and VEGF were shown to be more likely to integrate into the network formation than those treated with VEGF alone. The inhibition of EPC senescence by estrogen in vitro may improve the functional activity of EPCs in a way that is important for potential cell therapy.
    Journal of Hypertension 09/2005; 23(9):1699-706. DOI:10.1097/01.hjh.0000176788.12376.20 · 4.22 Impact Factor
  • Takuzo Hano, Ichiro Nishio
    Nippon rinsho. Japanese journal of clinical medicine 04/2005; 63 Suppl 3:533-6.
  • Takuzo Hano
    Nippon rinsho. Japanese journal of clinical medicine 04/2005; 63 Suppl 3:542-6.