Changes in salivary microbiota due to gastric cancer resection and its relation to gastric fluid microbiota

Gastric cancer is one of the leading causes of death worldwide, and resections are performed to cure the disease. We have previously reported the changes in the gastric microbiota after gastric cancer resection, which may be associated with the oral microbiota; however, the changes in the oral microbiota remain uncharacterized. This study aimed to characterize the changes in the salivary microbiota caused by gastric cancer resection and to evaluate their association with the gastric fluid microbiota. Saliva and gastric fluid samples were collected from 63 patients who underwent gastrectomy before and after surgery, and a 16S rRNA metagenomic analysis was performed to compare the microbiota composition. The number of bacterial species in the salivary microbiota decreased, and the bacterial composition changed after the resection of gastric cancer. In addition, we identified several bacterial genera that varied significantly in the salivary microbiota, some of which also showed similar changes in the gastric fluid microbiota. These findings indicate that changes in the gastric environment affect the oral microbiota, emphasizing the close association between the oral and gastric fluid microbiota. Our study signifies the importance of focusing on the oral microbiota in the perioperative period of gastrectomy in patients with gastric cancer.

0004 TS-142: A Novel and Potent Dual Orexin Receptor Antagonist with Sleep-Promoting Effects in Rats

Introduction

The orexin system plays a pivotal role in regulating sleep and wakefulness, thus, orexin receptors (OX1 and OX2 receptors) have gained much attention as promising therapeutic targets for the treatment of insomnia. We synthesized a novel and potent dual orexin receptor antagonist (DORA), ORN0829 (investigation code name as TS-142), which was designed to have short-acting effects. Here we report pharmacological and pharmacokinetic profiles of ORN0829 in rats.

Methods

The antagonistic activities of ORN0829 were assessed using calcium mobilization assays. Ala-orexin A-induced [Ca2+]i response was measured with CHO-K1 cells stably expressing human/rat orexin receptor. Rats implanted the EEG/EMG electrodes were orally administrated ORN0829 at doses of 1, 3 or 10 mg/kg at the dark onset and sleep-wake stages were inspected visually. In addition, pharmacokinetic profiles of ORN0829 were investigated in rats.

Results

ORN0829 inhibited Ala-orexin A-increased [Ca2+]i response with a Kb of 0.67/0.44 nmol/L (for human/rat OX1 receptor), and with a Kb of 0.84/0.80 nmol/L (for human/rat OX2 receptor), respectively, indicating that ORN0829 is a potent DORA with no species differences. ORN0829 dose-dependently increased total sleep time and reduced sleep onset latency at doses of 1, 3 and 10 mg/kg. Importantly, the ORN0829 levels in plasma and cerebrospinal fluid rapidly reached a maximum concentration, and decreased with an elimination half-life of less than 1 h.

Conclusion

The present study indicates that ORN0829 is a novel and potent DORA with sleep-promoting effects, and that it exhibits ideal pharmacokinetic profiles (rapid absorption and short half-life) in rats. A phase 2a study of TS-142 using patients with insomnia has been completed, which is presented in a separate poster.

Support

Taisho Pharmaceutical. Co., Ltd.

Vascular branches from cutaneous nerve of the forearm and hand: Application to better understanding raynaud's disease

Cutaneous nerves have branches called vascular branches (VBs) that reach arteries. VBs are thought to be involved in arterial constriction, and this is the rationale for periarterial sympathectomy as a treatment option for Raynaud's disease. However, the branching patterns and distribution areas of the VBs remain largely unclear. The aim of the present study was to investigate the anatomical structures of the VBs of the cutaneous nerves. Forty hands and forearms were examined to assess the branching patterns and distribution areas of the VBs of the superficial branch of the radial nerve (SBRN), the lateral antebrachial cutaneous nerve (LACN), the medial antebrachial cutaneous nerve (MACN), and the palmar cutaneous branch of the ulnar nerve (PCUN). VBs reaching the radial and ulnar arteries were observed in all specimens. The branching patterns were classified into six types. The mean distance between the radial styloid process and the point where the VBs reached the radial artery was 34.3 ± 4.8 mm in the SBRN and 38.5 ± 15.8 mm in the LACN. The mean distance between the ulnar styloid process and the point where the VBs reached the ulnar artery was 60.3 ± 25.9 mm in the MACN and 43.8 ± 26.0 mm in the PCUN. This study showed that the VBs of the cutaneous nerves have diverse branching patterns. The VBs of the SBRN had a more limited distribution areas than those of the other nerves. Clin. Anat. 31:734-741, 2018. © 2017 Wiley Periodicals, Inc.

Efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma

INTRODUCTION

Myomectomy for cervical myoma is problematic because cervical myomas are very close to neighboring structures, such as the ureters, uterine artery, bladder and rectum. There are a few reports on laparoscopic myomectomy for cervical myomas to avoid blood loss, such as occlusion of iliac arteries and clipping of the uterine artery. We evaluated the efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma.

METHODS

From November 2006 to May 2009, eight women with uterine cervical myoma underwent laparoscopic myomectomy. We employed electrode grasping forceps with a combination of two tenaculums for separating and securing hemostatsis.

RESULTS

Seven of eight cases were successfully treated by laparoscopic myomectomy, but one patient, with a large 900-g myoma was converted to the laparotomy as a result of blood loss (1800 mL). Among the other seven cases, the average weight of the myoma was 132 g (range, 16-310 g) and the operating time was 176 min. (range, 125-255 min). No complications occurred. Of the four cases who wanted to become pregnant postoperatively, two became pregnant and delivered by Caesarean section.

CONCLUSION

These findings indicate that bipolar electrode grasping forceps using two tenaculums for traction of the myoma are useful for laparoscopic myomectomy in cervical myomas.

Two-week cast immobilization induced chronic widespread hyperalgesia in rats

It has been postulated that physical immobilization is an essential factor in developing chronic pain after trauma or surgery in an extremity. However, the mechanisms of sustained immobilization-induced chronic pain remain poorly understood. The present study, therefore, aimed to develop a rat model for chronic post-cast pain (CPCP) and to clarify the mechanism(s) underlying CPCP. To investigate the effects of cast immobilization on pain behaviours in rats, one hindlimb was immobilized for 2 weeks with a cast and remobilization was conducted for 10 weeks. Cast immobilization induced muscle atrophy and inflammatory changes in the immobilized hindlimb that began 2 h after cast removal and continued for 1 week. Spontaneous pain-related behaviours (licking and reduction in weight bearing) in the immobilized hindlimb were observed for 2 weeks, and widespread mechanical hyperalgesia in bilateral calves, hindpaws and tail all continued for 5-10 weeks after cast removal. A sciatic nerve block with lidocaine 24 h after cast removal transitorily abolished bilateral mechanical hyperalgesia in CPCP rats, suggesting that sensory inputs originating in the immobilized hindlimb contribute to the mechanism of both ipsilateral and contralateral hyperalgesia. Intraperitoneal injection of the free radical scavengers 4-hydroxy-2,2,6,6-tetramethylpiperydine-1-oxy1 or N-acetylcysteine 24 h after cast removal clearly inhibited mechanical hyperalgesia in bilateral calves and hindpaws in CPCP rats. These results suggest that cast immobilization induces ischaemia/reperfusion injury in the hindlimb and consequent production of oxygen free radicals, which may be involved in the mechanism of widespread hyperalgesia in CPCP rats.

Estrogen and raloxifene induce apoptosis by activating p38 mitogen-activated protein kinase cascade in synthetic vascular smooth muscle cells

Proliferation of vascular smooth muscle cells (VSMC) plays a major role as an initiating event of atherosclerosis. Although estrogen directly inhibits the proliferation of VSMC, the mechanism has not been firmly established. In addition, the effect of raloxifene on VSMC remains unknown. 17Beta-estradiol (E(2)) and raloxifene significantly inhibited the growth of VSMC under growth-stimulated conditions. Since mitogen-activated protein (MAP) kinases have been implicated in VSMC proliferation, the role of MAP kinases in both the E(2)- and raloxifene-induced growth inhibition of VSMC was studied. Both E(2) and raloxifene caused rapid, transient phosphorylation and activation of p38 that was not affected by actinomycin D and was blocked by ICI 182,780. In contrast with p38 phosphorylation, extracellular signal-regulated protein kinase (ERK) phosphorylation was significantly inhibited and c-Jun N-terminal kinase (JNK) phosphorylation was not changed by E(2). Because VSMC expressed both estrogen receptor (ER) alpha and ERbeta, it is not known which of them mediates the E(2)-induced phosphorylation of p38. Although E(2) did not affect the p38 phosphorylation in A10 smooth muscle cells, which express ERbeta but not ERalpha, transfection of ERalpha expression vector into A10 cells rendered them susceptible to induction of p38 phosphorylation by E(2). We then examined whether E(2) and raloxifene induce apoptosis through a p38 cascade. Both E(2) and raloxifene induced apoptosis under growth-stimulated conditions. The p38 inhibitor SB 203580 completely blocked the E(2)-induced apoptosis. Our findings suggest that both E(2)- and raloxifene-induced inhibition of VSMC growth is due to induction of apoptosis through a p38 cascade whose activation is mediated by ERalpha via a nongenomic mechanism.

Both estrogen and raloxifene cause G1 arrest of vascular smooth muscle cells

The proliferation of vascular smooth muscle cells (VSMC) is a crucial pathophysiological process in the development of atherosclerosis. Although estrogen is known to inhibit the proliferation of VSMC, the mechanism responsible for this effect remains to be elucidated. In addition, the effect of raloxifene on VSMC remains unknown. We have shown here that 17beta-estradiol (E(2)) and raloxifene significantly inhibited the platelet-derived growth factor (PDGF)-stimulated proliferation of cultured human VSMC. Flow cytometry demonstrated that PDGF-stimulated S-phase progression of the cell cycle in VSMC was also suppressed by E(2) or raloxifene. We found that PDGF-induced phosphorylation of retinoblastoma protein (pRb), whose hyperphosphorylation is a hallmark of the G1-S transition in the cell cycle, was significantly inhibited by E(2) and raloxifene. These effects were associated with a decrease in cyclin D1 expression, without a change in cyclin-dependent kinase 4 or cyclin-dependent kinase inhibitor, p27(kip1) expression. ICI 182,780 abolished the inhibitory effects of E(2) and raloxifene on PDGF-induced pRb phosphorylation. Next, we examined which estrogen receptor (ER) is necessary for these effects of E(2) and raloxifene. Since VSMC express both ERalpha and ERbeta, A10, a rat aortic smooth muscle cell line that expresses ERbeta but not ERalpha, was used. The dose-dependent stimulation of A10 cell proliferation by PDGF was not inhibited by E(2) or raloxifene in contrast to the results obtained in VSMC. Moreover, E(2) and raloxifene significantly inhibited the PDGF-induced cyclin D1 promoter activity in A10 cells transfected with cDNA for ERalpha but not in the parental cells. These results suggested that E(2) and raloxifene exert an antiproliferative effect in VSMC treated with PDGF, at least in part through inhibition of pRb phosphorylation, and that the inhibitory effects of E(2) and raloxifene may be mainly mediated by ERalpha.

Increased circulating interleukin-12 (IL-12) p40 in pulmonary sarcoidosis

In sarcoidosis, a T helper 1 (Th1) response is an essential event and the up-regulation of interleukin-12 (IL-12) has been detected in affected disease sites. In order to investigate the clinical usefulness of circulating IL-12, we measured the serum concentrations of IL-12 by ELISA and performed immunohistochemistry using specific MoAbs for IL-12 in the lungs and scalene lymph nodes of patients with sarcoidosis. The serum concentration of IL-12 p40 was detectable in all 45 patients with pulmonary sarcoidosis and 18 normal controls, whereas that of IL-12 p70 was undetectable. The serum concentrations of IL-12 p40 in pulmonary sarcoidosis were significantly higher than those of the normal controls, especially in cases with abnormal intrathoracic findings detected by chest roentogenogram. The serum concentrations of interferon-gamma (IFN-gamma) also increased compared with those of normal controls and there was a significant positive correlation between the serum concentrations of IL-12 p40 and IFN-gamma. Furthermore, serum angiotensin-converting enzyme (ACE) and lysozyme, which are known to be useful markers for disease activity in sarcoidosis, correlated well with the serum concentrations of IL-12 p40. The positive 67Ga scan group (for lung field) had significantly elevated serum IL-12 p40 levels compared with those of the negative group. No bioactivity of IL-12 p70 was detected in three sarcoid cases sera by using the IL-12 responsive cell line. Finally, the immunohistochemical approach revealed that IL-12 p40 was expressed in the epithelioid cells and macrophages of sarcoid lungs and lymph nodes. We concluded that the production of IL-12 p40 was far greater in the sera and we have demonstrated this to be a useful clinical marker for disease activity and the Th1 response in pulmonary sarcoidosis.

Clinical features affecting the results of estrogen replacement therapy on bone density in Japanese postmenopausal women

Although estrogen replacement therapy (ERT) has been established as an effective treatment for postmenopausal bone loss, the clinical features which predict the effects of ERT have not been well investigated in Japanese postmenopausal women. We analyzed the role of physical factors influencing the effect of ERT on vertebral bone mineral density (BMD) in 94 Japanese postmenopausal women treated for 2 years or longer. The increase in BMD with ERT is 17.6 +/- 27.6 mg/cm(2)/year (mean +/- SD) during the first 2 years. Rates of BMD change were negatively correlated with the estimated initial BMD, and positively correlated with age and years since menopause, while no correlation was noted with the body mass index by a simple correlation analysis. The relationships between BMD change and estimated initial BMD or age also held in a multiple regression analysis. The estimated initial BMD and age together accounted for 34.4% of the BMD change during ERT. Furthermore, there were very few (2.4%) nonresponders with a negative linear regression slope of BMD in the osteoporosis and osteopenia group, although 32.7% of the normal initial BMD group were nonresponders. These results suggest that the initial BMD and age are potent predictive factors of the ERT effect on BMD change in Japanese postmenopausal women.

Non-invasive quantitative monitoring of cerebral blood flow in aneurysmal subarachnoid haemorrhage with 99mTc-ECD

The purpose of this prospective study was to detect symptomatic cerebral vasospasm in aneurysmal subarachnoid haemorrhage (SAH) by a non-invasive mean cerebral blood flow (mCBF) quantification using 99mTc-ethyl cysteinate dimer. Measurement of mCBF without blood sampling and single photon emission tomography (SPECT) were performed at 1 and 7 days after surgery in 35 consecutive SAH patients, of whom 16 were examined at day 30 as well. A decrease in mCBF of more than 10% on day 7 versus day 1 was considered to indicate vasospasm. On visual interpretation of SPECT, a perfusion decrease which appeared newly on day 7 was considered to indicate vasospasm. In total, nine of 35 patients had cerebral vasospasm confirmed by computed tomography (CT) and/or angiography. The mCBF measurement showed a 77.8% (7/9) sensitivity, a 88.5% (23/26) specificity, a 70.0% (7/10) positive predictive value, and a 92.0% (23/25) negative predictive value. SPECT yielded a 33.3% (3/9) sensitivity, a 73.1% (19/26) specificity, a 30.0% (3/10) positive predictive value, and a 76.0% (19/25) negative predictive value. On SPECT, decreased perfusion was observed in most of the patients at clipping sites, which might represent post-operative transient abnormal perfusion and should not be read as vasospasm. In conclusion, this mCBF measurement is more accurate than visual interpretation of SPECT for detecting vasospasm.

Induction of endothelial nitric-oxide synthase phosphorylation by the raloxifene analog LY117018 is differentially mediated by Akt and extracellular signal-regulated protein kinase in vascular endothelial cells

Raloxifene is a tissue-selective estrogen receptor modulator. The effect of estrogen on cardiovascular disease is mainly dependent on direct actions on the vascular wall involving activation of endothelial nitric oxide synthase (eNOS) via Akt and extracellular signal-regulated protein kinase (ERK) cascades. Although raloxifene is also known to activate eNOS in the vascular endothelium, the molecular mechanism responsible for this effect remains to be elucidated. In studies of both human umbilical vein endothelial cells and simian virus 40-transformed rat lung vascular endothelial cells (TRLECs), the raloxifene analog LY117018 caused acute phosphorylation of eNOS that was unaffected by actinomycin D and was blocked by the pure estrogen receptor antagonist ICI182,780. Activation of Akt by raloxifene reached a plateau at 15-30 min and declined thereafter, a similar time frame to that of Akt activation by 17beta-estradiol. On the other hand, both activation and phosphorylation of ERK by raloxifene showed a biphasic pattern (peaks at 5 min and 1 h), whereas ERK activation and phosphorylation by 17beta-estradiol reached a plateau at 5 min and declined thereafter. A MEK inhibitor, PD98059, had no effect on the raloxifene-induced Akt activity, suggesting an absence of cross-talk between the ERK and Akt cascades. Either exogenous expression of a dominant-negative Akt or pretreatment of TRLECs with PD98059 decreased the raloxifene-induced eNOS phosphorylation. Moreover, raloxifene stimulated the activation of Akt, ERK, and eNOS in Chinese hamster ovary cells expressing estrogen receptor alpha but not Chinese hamster ovary cells expressing estrogen receptor beta. Our findings suggest that raloxifene-induced eNOS phosphorylation is mediated by estrogen receptor alpha via a nongenomic mechanism and is differentially mediated by Akt- and ERK-dependent cascades.

Glutathione-conjugated arsenics in the potential hepato-enteric circulation in rats

The metabolic pathways for arsenic were precisely studied by determining the metabolic balance and chemical species of arsenic to gain an insight into the mechanisms underlying the animal species difference in the metabolism and preferential accumulation of arsenic in red blood cells (RBCs) in rats. Male Wistar rats were injected intravenously with a single dose of arsenite (iAs(III)) at 2.0 mg of As/kg of body weight, and then the time-dependent changes in the concentrations of arsenic in organs and body fluids were determined. Furthermore, arsenic in the bile was analyzed on anion and cation exchange columns by high-performance liquid chromatography-inductively coupled argon plasma mass spectrometry (HPLC-ICP MS). The metabolic balance and speciation studies revealed that arsenic is potentially transferred to the hepato-enteric circulation through excretion from the liver in a form conjugated with glutathione (GSH). iAs(III) is methylated to mono (MMA)- and dimethylated (DMA) arsenics in the liver during circulation in the conjugated form [iAs(III)(GS)(3)], and a part of MMA is excreted into the bile in the forms of MMA(III) and MMA(V), the former being mostly in the conjugated form [CH(3)As(III)(GS)(2)], and the latter being in the nonconjugated free form. DMA(III) and DMA(V) were not detected in the bile. In the urine, arsenic was detected in the forms of iAs(III), arsenate, MMA(V), and DMA(V), iAs(III) being the major arsenic in the first 6-h-urine, and DMA(V) being increased in the second 6-h-urine. The present metabolic balance and speciation study suggests that iAs(III) is methylated in the liver during its hepato-enteric circulation through the formation of the GSH-cojugated form [iAs(III)(GS)(3)], and MMA(III) and MMA(V) are partly excreted into the bile, the former being in the conjugated form [CH(3)As(III)(GS)(2)]. DMA is not excreted into the bile but into the bloodstream, accumulating in RBCs, and then excreted into the urine mostly in the form of DMA(V) in rats.

Combination therapy for sarcoidosis

Combination therapy has proved useful in infectious, rheumatologic, and oncologic diseases. The role of combination therapy in sarcoidosis is less defined. A stepwise approach to therapy in sarcoidosis treatment includes multiple agents, such as topical and systemic corticosteroids. The introduction of cytotoxic agents has led to the combination of these drugs with lowered doses of corticosteroids. Recently, the combination of cytotoxic and immune modifiers has been used for some cases of refractory sarcoidosis. The rationale use of combination therapy may enhance efficacy with reduced toxicity.

Identification of rat urinary and biliary metabolites of esonarimod, a novel antirheumatic drug, using liquid chromatography/electrospray ionization tandem mass spectrometry with postcolumn addition of 2-(2-methoxyethoxy)ethanol, a signal-enhancing modifier

The biotransformation of esonarimod (KE-298) [(+/-)-2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid], a new antirheumatic drug, was investigated in rats. Urinary and biliary excretions within 24 h after oral administration of 5 mg/kg [(14)C]esonarimod accounted for 89 and 10% of the dose, respectively. Initial metabolite analysis by liquid chromatography/electrospray ionization tandem mass spectrometry with negative ion mode, in which a mobile phase of 20 mM ammonium acetate (pH 4.6)/methanol with gradient-elution mode was used, failed to obtain any structural information on most of the metabolites due to poor sensitivity. To overcome this problem, postcolumn addition of 2-(2-methoxyethoxy)ethanol, a powerful signal-enhancing modifier, to the mobile phase was used, allowing pronounced signal enhancement and structural elucidation of urinary and biliary metabolites. The results of metabolite analysis suggested that esonarimod is predominantly biotransformed to a pharmacologically active metabolite, thiol-containing deacetyl-esonarimod (M-I), and subsequently undergoes extensive metabolism, mainly S-methylation followed by the combination of S-oxidation and oxidative conversion of the aromatic methyl group. No disulfide metabolites, such as M-I-cysteine mixed disulfide and M-I-dimer, were found in the excreta. This finding is probably evidence supporting the notion that the reactivity of the thiol moiety of M-I with macromolecules in vivo is extremely lower than that of common thiol-containing drugs.

Effects of bezafibrate and simvastatin on plasma lipoproteins in hypercholesterolemia resistant to hormone replacement therapy

OBJECTIVES

Estrogen replacement therapy has favorable effects on serum lipoprotein levels in postmenopausal women with hypercholesterolemia. However, there are some patients who fail to respond to hormone replacement therapy (HRT) to lower the serum cholesterol level. In these cases, a conventional lipid-lowering therapy will be applied in addition to HRT, while the effects of these drugs are not well understood. In this study, we studied the effects of simvastatin and bezafibrate administered in addition to HRT.

METHODS

Patients who were hypercholesterolemic even after HRT were randomly assigned to three treatment groups: HRT only (control group, n=10), HRT+simvastatin (10 mg/day, n=10), or HRT+bezafibrate (400 mg/day, n=10). Serum lipids and lipoprotein levels were measured throughout 12 weeks.

RESULTS

The serum triglyceride levels were decreased by 24+/-28 and 38+/-13% in the HRT+simvastatin and HRT+bezafibrate groups, respectively. HRT+simvastatin decreased the total cholesterol (21+/-10%) and low-density lipoprotein cholesterol (28+/-12%) levels without affecting the high-density lipoprotein cholesterol (HDL-C) level, while HRT+bezafibrate increased the HDL-C level (12+/-11%).

CONCLUSIONS

Treatment with simvastatin or bezafibrate in addition to HRT should be considered in cases of postmenopausal hypercholesterolemia in which HRT alone fails to lower the serum lipoprotein levels.

Element concentrations in urine of patients suffering from chronic arsenic poisoning

In order to know the element levels in the urine of patients with chronic arsenic poisoning caused by arsenic assimilated from burning coal via air and food, we investigated various elements in the urine of 16 patients with this disease and 16 controls living in the same county in Guizhou Province of China. Concentrations of 25 elements (Al, As, Ba, Be, Bi, Ca, Cd, Cr, Cu, Fe, Ga, Mg, Mn, Mo, Ni, P, Pb, Rb, Sb, Se, Sn, Sr, Ti, V and Zn) were determined by an inductively coupled plasma mass spectrometer or an inductively coupled plasma atomic emission spectrometer. The average concentrations of Cu, Ga and Sn as well as As in the patients were significantly higher, and those of Cr, Rb, Sr and Ti in the patients were significantly lower than the control values. Al, Ba, Mn, Ni and Se were under detection limit in the patients, though they could be detected in the controls. There were no positive correlations between the concentration of As and the concentrations of other elements, including Cu, Ga and Sn in the patients. The results of this study suggest that As from burning coal might influence the urinary excretion of some elements.

Estrogen induces the Akt-dependent activation of endothelial nitric-oxide synthase in vascular endothelial cells

Although estrogen is known to activate endothelial nitric oxide synthase (eNOS) in the vascular endothelium, the molecular mechanism responsible for this effect remains to be elucidated. In studies of both human umbilical vein endothelial cells (HUVECs) and simian virus 40-transformed rat lung vascular endothelial cells (TRLECs), 17beta-estradiol (E2), but not 17alpha-E2, caused acute activation of eNOS that was unaffected by actinomycin D and was specifically blocked by the pure estrogen receptor antagonist ICI-182,780. Treatment of both TRLECs and HUVECs with 17beta-E2 stimulated the activation of Akt, and the PI3K inhibitor wortmannin blocked the 17beta-E2-induced activation of Akt. 17beta-E2-induced Akt activation was also inhibited by ICI-182,780, but not by actinomycin D. Either treatment with wortmannin or exogenous expression of a dominant negative Akt in TRLECs decreased the 17beta-E2-induced eNOS activation. Moreover, 17beta-E2-induced Akt activation actually enhances the phosphorylation of eNOS. 17beta-E2-induced Akt activation was dependent on both extracellular and intracellular Ca(2+). We further examined the 17beta-E2-induced Akt activity in Chinese hamster ovary (CHO) cells transiently transfected with cDNAs for estrogen receptor alpha (ERalpha) or estrogen receptor beta (ERbeta). 17beta-E2 stimulated the activation of Akt in CHO cells expressing ERalpha but not in CHO cells expressing ERbeta. Our findings suggest that 17beta-E2 induced eNOS activation through an Akt-dependent mechanism, which is mediated by ERalpha via a nongenomic mechanism.