Late gadolinium enhancement in early repolarization syndrome.

BACKGROUND: In patients with Brugada syndrome, myocardial fibrosis can be identified through epicardial biopsy or cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE). However, the myocardial alterations in patients with early repolarization syndrome (ERS) remain poorly elucidated. OBJECTIVE: The objective of this study was to investigate the presence of myocardial fibrosis in patients with ERS by LGE in CMR. METHODS: We retrospectively evaluated 20 patients with ERS, all of whom exhibited J waves in the contiguous 2 leads. The location of J waves was classified as in the septum (V1-V2), anterior (V3-V4), lateral (I, aVL, V5-V6), inferior (II, III, aVF), or posterior (V7-V9) regions. To compare the distribution of LGE on CMR imaging with J waves, sections on short-axis view of the left ventricle (LV) were categorized as located in the septum, anterior, lateral, inferior, and posterior regions. RESULTS: Overall, 85% of ERS patients displayed LGE, which was more prevalent in the septum and posterior regions, followed by the inferior and lateral regions. The presence or absence of J waves and LGE coincided in 61% of LV areas, whereas discordance between the distributions of J waves and LGE was observed in 38%. LGE was most frequent in the septum (75%), where its reflection in J waves may be less robust. The appearance of LGE was not associated with symptoms, electrical storm, or ventricular fibrillation occurrence during follow-up. CONCLUSION: LGE is common in patients with ERS, and the distribution of J waves and LGE coincides in approximately 60% of LV areas.

Impact of extracardiac sarcoidosis on clinical outcomes in patients with cardiac sarcoidosis: Importance of continued screening for cardiac involvement.

BACKGROUND: The prognostic impact of extracardiac sarcoidosis remains unknown in cardiac sarcoidosis (CS). We aimed to evaluate the influence of extracardiac sarcoidosis on clinical outcomes and the effect of continued outpatient visits for screening of cardiac involvement. METHODS: Ninety-nine patients with CS were divided into two groups: patients with systemic CS who had prior extracardiac sarcoidosis, patients with isolated CS who had no prior extracardiac sarcoidosis. Patients with systemic CS were divided according to the continuation of outpatient visits. The endpoint was cardiac death, fatal ventricular arrhythmia, or hospitalization for heart failure. RESULTS: At the time of diagnosing CS, patients with isolated CS had a higher prevalence of high-grade atrioventricular block or fatal ventricular arrhythmia, and left ventricular contractile dysfunction than those with systemic CS. Over a median follow-up of 42 months, cardiac events occurred in 19 (37%) of 52 patients with systemic CS and in 27 (57%) of 47 patients with isolated CS. The event-free survival rate was worse in patients with isolated CS than in those with systemic CS. Cox proportional hazard analysis showed that the absence of prior extracardiac sarcoidosis was an independent predictor of adverse outcomes. Patients with systemic CS who ceased outpatient visits had a lower left ventricular ejection fraction with severe heart failure symptoms and a worse event-free survival rate than those who continued outpatient visits. CONCLUSIONS: The presence of extracardiac sarcoidosis is associated with clinical outcomes. The cessation of screening for cardiac involvement after diagnosing extracardiac sarcoidosis is associated with adverse outcomes.

Risk stratification for the occurrence of ventricular fibrillation in patients with early repolarization syndrome.

BACKGROUND: Several signs of malignant early repolarizations have been proposed in patients with early repolarization syndrome (ERS). However, reports have challenged the efficacy of these signs in predicting future ventricular fibrillation (VF) in patients with ERS. OBJECTIVE: This study aimed to assess the predictive value of various electrocardiogram (ECG) markers for future VF events in patients with ERS. METHODS: We retrospectively evaluated the clinical characteristics of 44 patients with ERS to identify risk factors for VF during follow-up. RESULTS: After the initial event, 16 patients experienced VF (VF group), whereas 28 did not (non-VF group). The VF group had a longer QRS interval, more fragmented QRS (fQRS), and a higher T/R voltage ratio than the non-VF group. Wide J waves were more prevalent in the VF group; however, other J-wave markers did not differ between the groups. Positive late potentials recorded on signal-averaged ECGs were more frequent in the VF group. Whereas none of the patients showed spontaneous Brugada syndrome on ECG, the VF group frequently exhibited pilsicainide-induced ST-segment elevation. These ECG markers were significantly associated with the occurrence of VF during follow-up. Patients with multiple ECG factors, including QRS abnormalities (wide QRS or fQRS), wide J waves, and a high T/R ratio, had a worse prognosis than patients without multiple factors, effectively stratifying patient risk. CONCLUSION: The occurrence of VF in patients with ERS may be associated with conduction abnormalities such as QRS widening, fQRS, high T/R ratio, positive late potentials, and pilsicainide test results. Therefore, ECG factors could be useful in identifying high-risk patients.

Effects of Combination Therapy with Intravitreal Ranibizumab and Tissue Plasminogen Activator for Neovascular Age-Related Macular Degeneration.

Background: Subretinal hyper-reflective material (SHRM) sometimes causes vision loss in spite of anti-vascular endothelial growth factor (VEGF) therapy in eyes with neovascular age-related macular degeneration (nvAMD). We evaluated the impacts of combination therapy with intravitreal ranibizumab (IVR) and tissue plasminogen activator (tPA) in eyes with nvAMD accompanying SHRM. Methods: In total, 25 eyes of 25 patients (16 men and 9 women, 76.7 years old), who underwent IVR/tPA for nvAMD with SHRM and were followed up for at least 12 months, were retrospectively reviewed. In total, 15 eyes were treatment-naïve and 10 eyes had previous treatment for nvAMD. Results: In total, 16 eyes had type 2 macular neovascularization (MNV), 5 eyes type 1 MNV with fibrovascular pigment epithelial detachment and 4 eyes polypoidal choroidal vasculopathy. At month 12, SHRM regressed or reduced in 18 eyes (72%) and the best-corrected visual acuity (BCVA) improved in 6 eyes (24%) and was unchanged in 14 eyes (56%), while the mean BCVA was just stabilized. The mean central retinal thickness, macular volume and SHRM thickness significantly improved from 408 µm to 287 µm, from 11.9 mm3 to 9.6 mm3, from 369 µm to 165 µm, respectively (p < 0.01). Conclusions: The combination therapy with IVR/tPA for nvAMD with SHRM may help preserve vision by prompt regression of SHRM.

Vincazalidine A, a unique bisindole alkaloid from Catharanthus roseus.

A new dimeric indole alkaloid, vincazalidine A consisting of an aspidosperma type and a modified iboga type with 1-azatricyclo ring system consisting of one azepane and two piperidine rings coupled with an oxazolidine ring was isolated from Catharanthus roseus, and the structure including absolute stereochemistry was elucidated on the basis of spectroscopic data as well as DP4 statistical analysis. Vincazalidine A induced G2 arrest and subsequent apoptosis in human lung carcinoma cell line, A549 cells.

Prevalence and Treatment of Arrhythmias in Patients With Transthyretin and Light-Chain Cardiac Amyloidosis.

Background: Various types of arrhythmia are observed in patients with cardiac amyloidosis, but the prevalence of arrhythmia has not been fully investigated. This study investigated the prevalence and treatment of arrhythmias in patients with cardiac amyloidosis before the introduction of new agents for amyloidosis, such as tafamidis. Methods and Results: Of 53 patients who were histologically diagnosed with cardiac amyloidosis at 10 centers in western Japan between 2009 and 2021, 43 who were diagnosed on the basis of immunohistochemical staining were evaluated in this study. Of these 43 patients, 13 had immunoglobulin light-chain (AL) amyloidosis and 30 had transthyretin (ATTR) amyloidosis; further, 27 had atrial tachyarrhythmia, 13 had ventricular tachyarrhythmia, and 17 had bradyarrhythmia. Atrial fibrillation (AF) was the most common arrhythmia in patients with cardiac amyloidosis (n=24; 55.8%), especially among those with ATTR amyloidosis (70.0% of ATTR vs. 23.1% of AL). Eleven (25.6%) patients were treated with a cardiac implantable device. All 3 patients with pacemakers were alive at the last follow-up (median 76.7 months; interquartile range [IQR] 4.8-146.4 months). Of the 8 patients who underwent AF ablation, there was no recurrence in 6 (75%) after a median of 39.3 months (IQR 19.8-59.3 months). Conclusions: The prevalence of various arrhythmias was high in patients with cardiac amyloidosis. AF occurred most frequently in patients with cardiac amyloidosis, especially among patients with ATTR.

Disentangling Origins of Adhesive Bonding at Interfaces between Epoxy/Amine Adhesive and Aluminum.

Joining metals by adhesive bonding is essential in widespread fields such as mobility, dentistry, and electronics. Although adhesive technology has grown since the 1920s, the roles of interfacial phenomena in adhesive bonding are still elusive, which hampers the on-demand selection of surface treatment and adhesive types. In the present study, we clarified how chemical interactions and mechanical interlocking governed adhesive bonding by evaluating adhesion properties at the interfaces between epoxy/amine adhesive and two kinds of Al adherends: a flat aluminum hydroxide (AlxOyHz) and technical Al plate with roughness. Spectroscopic and microscopical data demonstrate that the protonation of the amino groups in an amine hardener converts Al(OH)3 on the AlxOyHz surface to AlO(OH). The interfacial protonation results in an interfacial dipole layer with positive charges on the adhesive side, whose electrostatic interaction increases the interfacial fracture energy. The double cantilever beam tests for the flat AlxOyHz and technical Al substrates clarify that the mechanical interlocking originating from the surface roughness further increases the fracture energy. This study disentangles the roles of the chemical interactions and mechanical interlocking occurring at the epoxy adhesive/Al interface in the adhesion mechanism.

Effects of Agalsidase Alfa Enzyme Replacement Therapy on Left Ventricular Hypertrophy on Electrocardiogram in a Female Patient with Fabry Disease.

Fabry disease is an X-linked lysosomal storage disorder caused by defective enzyme activity of α-galactosidase A and treated with enzyme replacement therapy (ERT) with recombinant α-galactosidase. ERT reduces left ventricular mass assessed by echocardiography or magnetic resonance imaging. However, electrocardiogram changes during ERT have not been fully elucidated. In the present case, ERT with agalsidase alfa for 4 years decreased QRS voltage and negative T depth along with a reduction of left ventricular mass and wall thickness and improvement of symptoms in a female patient with Fabry disease. Long-term observation of electrocardiogram changes might be useful for determining the efficacy of ERT in this case.

Quassinoids from Eurycoma longifolia Jack roots and their potential inhibitory activity against human benign prostatic hyperplasia cells (BPH-1) and testosterone-induced BPH rat model.

Benign prostate hyperplasia (BPH) is an enlargement of the prostate gland, because of hormonal changes in aging males which contribute significantly to excessive proliferation over apoptosis of prostatic cells. The anti-proliferative and induced apoptotic activities of Eurycoma longifolia quassinoids on cancer cell lines could be promising therapeutic targets on BPH. Hitherto, no report of the quassinoids against BPH problem was available. In this study, a systematic phytochemical fractionation of the root extract, TAF2 was performed, which led to the discovery of nine previously described C20 quassinoids (1-9). Two undescribed C20 (10 and 12) and one undescribed (11) C19 quassinoids were identified by detailed NMR and HR-ESI-MS data analysis. Their absolute configurations were assigned by ECD spectral analysis. The quassinoids (1-12) were tested for inhibitory activity against the proliferation of human BPH-1 and human skin Hs27 fibroblast cells cultured in vitro. 1, 2 and 3 at 10 µM significantly reduced BPH-1 cell viability and were cytotoxic to Hs27 fibroblast cells. 2 was selected for further study of anti-BPH activity against testosterone induced BPH rats. At 5 mg/kg, 2 reduced the rat prostatic weight and prostatic index, consistent with the decrease in papillary acini number and epithelial thickness of the prostate tissues. These quassinoids may be potential anti-BPH compounds that require further studies.

Calofolic Acid-A from Calophyllum scriblitifolium Bark Has Vasorelaxant Activity via Indirect PKA Activation Caused by PI-3 Kinase Inhibition in Rat Vascular Smooth Muscle Cells.

Previously, we isolated 2R,3S,15R-calofolic acids (CAs) from Calophyllum scriblitifolium bark, which showed vasorelaxant activity on phenylephrine (PE)-precontracted rat aortic rings. Although the effect was suggested to be induced via an extracellular Ca2+-independent manner and mainly acts on vascular smooth muscle, the exact mechanism of action of CAs remained unclear. Thus, this study investigated the detailed mechanism of calofolic acid-A (CA-A) induced vasorelaxation in an aortic ring specimen using rat vascular smooth muscle cells (VSMCs). The levels of PE-induced phosphorylation on MLC Ser19 decreased in VSMCs pretreated with CA-A. CA-A also decreased the phosphorylation of MYPT1 Thr696 and MYPT1 Thr853. On the other hand, CA-A increased the PE-induced phosphorylation of MYPT1 Ser695 and MYPT1 Ser668, which are reported to be phosphorylated by a cAMP-dependent protein kinase (PKA). CA-A slightly increased PKA substrate phosphorylation in a concentration-dependent manner. Furthermore, CA-A enhanced isoproterenol (ISO)-induced cAMP accumulation and PKA substrate phosphorylation. Treatment with PI-3 kinase (PI3K) inhibitor, LY294002, enhanced ISO-induced cAMP accumulation and PKA substrate phosphorylation in the same manner as CA-A treatment. Furthermore, CA-A was found to directly inhibit PI3K enzyme activity in a dose-dependent manner. Taken together, the present study indicated that CA-A induces vasorelaxation through an indirectly activated PKA-MYPT1 pathway caused by inhibition of PI3K activity.

Mental Status and Feasibility of an Intravitreal Ranibizumab Treat-and-Extend Regimen in Patients with Neovascular Age-Related Macular Degeneration.

INTRODUCTION: Anti-vascular endothelial growth factor (VEGF) therapy is the first-choice treatment for neovascular age-related macular degeneration (nvAMD); however, patients often are burdened physically, financially, and mentally. We investigated the relationship between mental status and feasibility of an intravitreal ranibizumab treat-and-extend (TAE) regimen for nvAMD. METHODS: In this prospective, multicenter study, 75 patients with nvAMD received ranibizumab intravitreally in a TAE regimen. After two monthly injections, the injection intervals were extended step-by-step to 6, 8, 12, and 16 weeks in eyes with dry maculas on optical coherence tomography (OCT) and, if exudation persisted or relapsed, shortened by one step. The best corrected visual acuity (BCVA) measurement and OCT were performed at baseline and on the same days of the scheduled injections. At baseline, all patients completed a survey, the Hospital Anxiety and Depression Scale (HADS), regarding mental burden. At week 52, patients on the TAE regimen for 1 year completed the HADS and a questionnaire designated to assess treatment-associated mental status. RESULTS: Fifty-one patients (68%) completed the 1-year TAE regimen; 24 eyes (32%) discontinued the TAE regimen because of the rescue treatment, difficulty in completing clinical visits, or financial burden. In 51 eyes on the TAE regimen for 1 year, the mean BCVAs improved from 64.3 letters at baseline to 71.6 letters at week 52. The mean anxiety and depression scores on HADS decreased significantly (p < 0.01) after the 1-year treatment. Women tended to have higher anxiety scores, possibly associated with fear of injection and recurrence, while some men had higher depression scores potentially associated with financial burden, difficulty in completing clinical visits, and subsequent interruption of the TAE regimen especially in eyes with low treatment efficacy. CONCLUSIONS: A TAE regimen of intravitreal ranibizumab injections preserves vision in eyes with nvAMD and reduces mental burden associated with disease relapse. TRIAL REGISTRATION: This clinical study was registered retrospectively on December 22, 2014 with the ClinicalTrials.gov identifier NCT02321839.

Pacemaker implantation via femoral vein and successful arrhythmia management in an elderly patient with Fontan circulation: a case report.

BACKGROUND: The frequency of arrhythmias increases after the Fontan operation over time; atrial tachycardia (AT) and sinus node dysfunction (SND) are frequently observed. CASE SUMMARY: Our patient was 63-year-old woman who underwent a lateral tunnel Fontan operation for double outlet right ventricle at age 36. She experienced paroxysmal AT for 1 year, and antiarrhythmic medication was not feasible due to symptomatic SND. Computed tomography revealed a 45 mm-sized thrombus in the high right atrium (RA). The patient had three coexisting conditions: paroxysmal AT, symptomatic SND, and the right atrial thrombus, for which total cavopulmonary connection conversion and epicardial pacemaker implantation (PMI) would have been effective; however, given her age and comorbidities, surgical treatment was considered high risk. Catheter ablation was avoided because of the right atrial thrombus. Finally, a transvenous pacemaker was implanted via the right femoral vein to avoid the right atrial thrombus and severe venous tortuosity from the left subclavian vein to the RA. After PMI, the patient was prescribed amiodarone and bisoprolol for AT suppression. Atrial tachycardia occurred once in the third month after discharge. We increased the dose of amiodarone, and she has been tachycardia-free. DISCUSSION: Transvenous PMI must be considered in cases where open thoracic surgery or catheter ablation cannot be performed. This is the first report of transvenous PMI via the right femoral vein and successful AT and SND management in an elderly Fontan patient.

Two new bisindole alkaloids from Tabernaemontana macrocarpa Jack.

Two new bisindole alkaloids, bisnaecarpamines A (1) and B (2), possessing a vobasine-sarpagine type skeleton were isolated from the bark of Tabernaemontana macrocarpa Jack. Their structures were elucidated by extensive spectroscopic methods and chemical correlation. The absolute configurations of compounds 1 and 2 were established using TDDFT-ECD calculation of the selected isomers. Bisnaecarpamine A exhibited potent antimalarial activity against Plasmodium falciparum 3D7 strain with IC50 value of 28.8 µM.

Pathological and clinical effects of interleukin-6 on human myocarditis.

BACKGROUND: Numerous basic studies have shown a relationship between interleukin-6 (IL-6) and the development or severity of myocarditis. However, there has been no study in which the effect of IL-6 levels in patients with myocarditis was evaluated. METHODS: We enrolled control patients (n = 12) and consecutive patients with acute myocarditis (n = 13), including lymphocytic, eosinophilic, and giant cell myocarditis, and investigated the pathological and clinical effects of IL-6 on human myocarditis. RESULTS: The serum IL-6 level in patients with myocarditis (16.7 [9.9, 103.8] pg/mL) was significantly higher than that in the control patients (1.4 [1.0, 1.9] pg/mL) (P<0.001). Immunohistochemical analysis showed that IL-6 was expressed in infiltrating inflammatory cells of endomyocardial biopsy samples from all patients with myocarditis. Moreover, the log-transformed value of serum IL-6 level showed significant positive correlations with serum creatine kinase (CK) level, CK-MB level, peak CK level, peak CK-MB level and C-reactive protein level (all P ≤ 0.005) and a negative correlation with the left ventricular (LV) ejection fraction (p = 0.014). We divided the patients with myocarditis into a low IL-6 group (9.9 [4.5, 14.2] pg/dL, n = 7) and a high IL-6 group (108.9 [51.1, 130.9] pg/dL, n = 6). The degree of infiltration of IL-6-expressing inflammatory cells in myocardial samples obtained from patients in the high IL-6 group was significantly more severe than that in samples obtained from patients in the low IL-6 group. Furthermore, patients in the high IL-6 group significantly more frequently received catecholamine therapy (P = 0.005), venoarterial extracorporeal membrane oxygenation (P = 0.029), and artificial respirator support (P = 0.021) in the acute phase of myocarditis. CONCLUSION: The results suggest that there is a strong impact of IL-6 on cardiac injury and dysfunction in patients with myocarditis.

Triterpenoids from Walsura trichostemon.

Bioactivity guided separation of Walsura trichostemon stem methanolic extract led to the isolation of four new dammarane (1-4) and two new apotirucallane triterpenoids (5-6), together with one limonoid (7), 11,25-dideacetyltrichostemonate, 12ß, 20S, 24R-trihydroxydammar-25-en-3-one and 12ß, 20S, 25-trihydroxydammar-23-en-3-one. Compounds 1-7 showed in vitro inhibitory activity on the proliferation of A549, human lung adenocarcinoma cell line.

Correction to: Cycloartane triterpenoid (23R, 24E)-23-acetoxymangiferonic acid inhibited proliferation and migration in B16-F10 melanoma via MITF downregulation caused by inhibition of both ß-catenin and c-Raf-MEK1-ERK signaling axis.

The article Cycloartane triterpenoid (23R, 24E)-23-acetoxymangiferonic acid inhibited proliferation and migration in B16-F10 melanoma via MITF downregulation caused by inhibition of both ß-catenin.

Effects of Bisoprolol Transdermal Patches for Prevention of Perioperative Myocardial Injury in High-Risk Patients Undergoing Non-Cardiac Surgery　- Multicenter Randomized Controlled Study.

BACKGROUND: The aim of this study was to evaluate the efficacy and safety of transdermal ß-blocker patches, which offer stable blood concentration and easy availability during operation, for prevention of perioperative myocardial injury (PMI) in high-risk patients.Methods and Results:In this randomized controlled trial, patients aged >60 years with hypertension and high revised cardiac risk index (≥2) undergoing non-cardiac surgery were randomly assigned to a bisoprolol patch or control group. Primary efficacy outcome was incidence of PMI, defined as postoperative high-sensitivity cardiac troponin T (hs-cTnT) >0.014ng/mL and relative hs-cTnT change ≥20%. Secondary efficacy outcomes were number of cardiovascular events and 30-day mortality. From November 2014 to February 2019, 240 patients from 5 hospitals were enrolled in this study. The incidence of PMI was 35.7% in the bisoprolol patch group and 44.5% in the control group (P=0.18). Incidence of major adverse cardiac events including non-critical myocardial infarction, strokes, decompensated heart failure and tachyarrhythmia was similar between the 2 groups. Tachyarrhythmia tended to be higher in the control group. There were no significant differences in safety outcomes including significant hypotension and bradycardia requiring any treatment between the 2 groups. CONCLUSIONS: Bisoprolol patches do not influence the incidence of PMI and cardiovascular events in high-risk patients undergoing non-cardiac surgery, but perioperative use of these patches is safe.

Anti-tumor Effects of Cyclolinopeptide on Giant-cell Tumor of the Bone.

AIM: This study aimed to evaluate the antitumor effects of cyclolinopeptide (CL), which suppresses receptor activator of nuclear factor-κB ligand (RANKL) signalling on giant-cell tumours of the bone (GCTB) cells. MATERIALS AND METHODS: GCTB cell lines were established, and the inhibition of cell growth by CL was evaluated using the water-soluble tetrazolium salt-8 cell proliferation assay, cell cycle assay, and 5-ethynyl-2'-deoxyuridine (EdU) cell proliferation assay. RANKL and runt-related transcription factor 2 (RUNX2) expression levels were evaluated using real-time polymerase chain reaction before and after CL administration. RESULTS: The dose-dependent inhibition of GCTB cells was significantly pronounced in the CL-administered group compared to the non-CL-administered group (p<0.05). In the CL-administered group, the ratio of cells in the G0/G1 phase was increased, but the ratio of EdU-positive cells was decreased (p<0.05). RANKL and RUNX2 levels were decreased in the CL-administered group (p<0.05). CONCLUSION: CL has antitumor effects on GCTB in vitro.

G-protein-coupled receptor 40 agonist GW9508 potentiates glucose-stimulated insulin secretion through activation of protein kinase Cα and ε in INS-1 cells.

OBJECTIVE: The mechanism by which G-protein-coupled receptor 40 (GPR40) signaling amplifies glucose-stimulated insulin secretion through activation of protein kinase C (PKC) is unknown. We examined whether a GPR40 agonist, GW9508, could stimulate conventional and novel isoforms of PKC at two glucose concentrations (3 mM and 20 mM) in INS-1D cells. METHODS: Using epifluorescence microscopy, we monitored relative changes in the cytosolic fluorescence intensity of Fura2 as a marker of change in intracellular Ca2+ ([Ca2+]i) and relative increases in green fluorescent protein (GFP)-tagged myristoylated alanine-rich C kinase substrate (MARCKS-GFP) as a marker of PKC activation in response to GW9508 at 3 mM and 20 mM glucose. To assess the activation of the two PKC isoforms, relative increases in membrane fluorescence intensity of PKCα-GFP and PKCε-GFP were measured by total internal reflection fluorescence microscopy. Specific inhibitors of each PKC isotype were constructed and synthesized as peptide fusions with the third α-helix of the homeodomain of Antennapedia. RESULTS: At 3 mM glucose, GW9508 induced sustained MARCKS-GFP translocation to the cytosol, irrespective of changes in [Ca2+]i. At 20 mM glucose, GW9508 induced sustained MARCKS-GFP translocation but also transient translocation that followed sharp increases in [Ca2+]i. Although PKCα translocation was rarely observed, PKCε translocation to the plasma membrane was sustained by GW9508 at 3 mM glucose. At 20 mM glucose, GW9508 induced transient translocation of PKCα and sustained translocation as well as transient translocation of PKCε. While the inhibitors (75 µM) of each PKC isotype reduced GW9508-potentiated, glucose-stimulated insulin secretion in INS-1D cells, the PKCε inhibitor had a more potent effect. CONCLUSION: GW9508 activated PKCε but not PKCα at a substimulatory concentration of glucose. Both PKC isotypes were activated at a stimulatory concentration of glucose and contributed to glucose-stimulated insulin secretion in insulin-producing cells.