Tyrosine hydroxylase activity in the endocrine pancreas: changes induced by short-term dietary manipulation

BACKGROUND: Tyrosine hydroxylase (TH) activity and its possible participation in the control of insulin secretion were studied in pancreatic islets of adult Wistar rats fed a standard commercial diet (SD) or carbohydrates alone (CHD) for one week. TH activity, norepinephrine (NE) content, and glucose-induced insulin secretion were assessed. Blood glucose and insulin levels were measured at the time of sacrifice. RESULTS: CHD rats had significantly higher blood glucose and lower insulin levels than SD rats (114.5 ± 6.7 vs 80.7 ± 7.25 mg/dl, p < 0.001; 20.25 ± 2.45 vs 42.5 ± 4.99 μU/ml, p < 0.01, respectively). Whereas TH activity was significantly higher in CHD isolated islets (600 ± 60 vs 330 ± 40 pmol/mg protein/h; p < 0.001), NE content was significantly lower (18 ± 1 vs 31 ± 5 pmol/mg protein), suggesting that TH activity would be inhibited by the end-products of catecholamines (CAs) biosynthetic pathway. A similar TH activity was found in control and solarectomized rats (330 ± 40 vs 300 ± 80 pmol/mg protein/h), suggesting an endogenous rather than a neural origin of TH activity. CHD islets released significantly less insulin in response to glucose than SD islets (7.4 ± 0.9 vs 11.4 ± 1.1 ng/islet/h; p < 0.02). CONCLUSIONS: TH activity is present in islet cells; dietary manipulation simultaneously induces an increase in this activity together with a decrease in glucose-induced insulin secretion in rat islets. TH activity – and the consequent endogenous CAs turnover – would participate in the paracrine control of insulin secretion

Antidepressant effect in older depressed patients: the lessons of two agomelatine trials

The present paper reports in parallel the findings of the two phase III trials that evaluated the efficacy of agomelatine in older depressed patients. It describes how the particular methodological innovations (particularly in relation to patient selection, design and accuracy of diagnosis of depression) introduced in study 2 have improved the quality of recruitment of patients and the assay sensitivity. Study 1 lacked assay sensitivity, and among the many differences with study 2, the inclusion of unexpected mildly ill patients could have inflated the placebo response. The increased demands on investigators in study 2 appear to have reduced the placebo effect and showed a robust benefit of agomelatine. The two agomelatine studies offer the opportunity to discuss hypotheses that have been raised to explain the low level of response of older patients to available antidepressants

Early effect on general interest, and short-term antidepressant efficacy and safety of agomelatine (25–50mg/day) and escitalopram (10–20mg/day) in outpatients with Major Depressive Disorder. A 12-week randomised double-blind comparative study

International audienc

Clin Drug Investig

Background and Objectives Non-interventional studies are a valuable source of evidence that is complementary to traditional randomised, blinded and controlled clinical trials, for evaluating antidepressants in a real-world setting. The aim of the present study was to document the use of agomelatine in current medical practice and evaluate its effectiveness and safety in outpatients prescribed agomelatine to treat their current depressive episode. Methods This 12-month observational French study included patients initiating agomelatine treatment. The intensity and severity of depression were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D17) total score and the Clinical Global Impression-Severity of Illness (CGI-S) scale. Patients’ quality of life and functioning were measured using the Quality of Life in Depression Scale and the Sheehan Disability Scale, respectively. The safety measures included emergent adverse events and biological samplings, with a focus on liver acceptability. Results A total of 1484 patients (70% of women; 49.6 ± 15.4 years of age) were enrolled in the study. Most patients (62.3%) were treated with agomelatine for at least 6 months and 28.8% were treated for at least 1 year. Mean HAM-D17 total score and mean CGI-S scores decreased by 13.6 ± 8.1 and 2.1 ± 1.5 points, respectively, from baseline to last visit on agomelatine. Rates of responders (i.e. with a decrease in HAM-D17 total score by at least 50%) and remitters (HAM-D total score < 7) at the last visit were 90.7% and 56.0%, respectively. The mean HAM-D total score decreased after agomelatine withdrawal (− 4.1 ± 6.7) until the last visit. The quality of life and daily functioning of patients improved, while the numbers of days lost and underproductive days decreased over the follow-up period. Safety findings were in accordance with the known information regarding agomelatine. Conclusion In the current medical practice, this study confirms the effectiveness and good tolerability of agomelatine administered for a treatment period in agreement with guideline recommendations

Efficacy of the novel antidepressant agomelatine on the circadian rest-activity cycle and depressive and anxiety symptoms in patients with major depressive disorder: a randomized, double-blind comparison with sertraline.

OBJECTIVE: This study evaluates the efficacy of agomelatine, the first antidepressant to be an agonist at MT(1)/MT(2) receptors and an antagonist at 5-HT(2C) receptors, versus sertraline with regard to the amplitude of the circadian rest-activity cycle and depressive and anxiety symptoms in patients with major depressive disorder (MDD). METHOD: Outpatients with DSM-IV-TR-defined MDD received either agomelatine 25 to 50 mg (n = 154) or sertraline 50 to 100 mg (n = 159) during a 6-week, randomized, double-blind treatment period. The study was conducted from 2005 to 2006. The main outcome measure was the relative amplitude of the individual rest-activity cycles, expressed as change from baseline to week 6 and collected from continuous records using wrist actigraphy and sleep logs. Secondary outcome measures were sleep efficiency and sleep latency, both derived from actigraphy, and efficacy on depression symptoms (17-Item Hamilton Depression Rating Scale total score and Clinical Global Impressions scale scores) and anxiety symptoms (Hamilton Anxiety Rating Scale total score and subscores). RESULTS: A significant difference in favor of agomelatine compared to sertraline on the relative amplitude of the circadian rest-activity cycle was observed at the end of the first week (P = .01). In parallel, a significant improvement of sleep latency (P &lt;.001) and sleep efficiency (P &lt;.001) from week 1 to week 6 was observed with agomelatine as compared to sertraline. Over the 6-week treatment period, depressive symptoms improved significantly more with agomelatine than with sertraline (P &lt;.05), as did anxiety symptoms (P &lt;.05). CONCLUSIONS: The favorable effect of agomelatine on the relative amplitude of the circadian rest-activity/sleep-wake cycle in depressed patients at week 1 reflects early improvement in sleep and daytime functioning. Higher efficacy results were observed with agomelatine as compared to sertraline on both depressive and anxiety symptoms over the 6-week treatment period, together with a good tolerability profile. These findings indicate that agomelatine offers promising benefits for MDD patients. TRIAL REGISTRATION: www.isrctn.org: ISRCTN49376288

12-week double-blind randomized multicenter study of efficacy and safety of agomelatine (25-50 mg/day) versus escitalopram (10-20 mg/day) in out-patients with severe generalized anxiety disorder

Treatment of severely symptomatic patients with generalized anxiety disorder (GAD) raises particular concerns for clinicians. This 12-week double-blind study evaluated the efficacy of agomelatine (25-50 mg/day) in the treatment of patients with severe GAD, using escitalopram (10-20 mg) as active comparator. The primary outcome measure was the change from baseline of the total score on the Hamilton Anxiety scale (HAM-A) at week 12. Secondary outcome measures included rate of response to treatment (at least 50% score reduction from baseline) in the HAM-A psychic and somatic anxiety sub-scores, Clinical Global Impression severity and change scores, the Toronto Hospital Alertness Test, the Snaith-Hamilton Pleasure Scale, and the Leeds Sleep Evaluation Questionnaire Scores. Sixty one clinical centers (Australia, Canada, Czech Republic, Finland, Germany, Hungary, Poland, Russia, Slovakia) participated from April 2013 to February 2015. Patient characteristics and demographic data were comparable between treatment groups. Both treatments were associated with a clinically significant decrease in HAM-A total score at week 12; the non-inferiority of agomelatine versus escitalopram was not demonstrated (E(SE) = -0.91(0.69), 95% CI = [-2.26, 0.44], p = 0.195). At week 12, the response rate was 60.9% in the agomelatine group, and 64.8% in the escitalopram group. In both treatment arms, HAM-A psychic and somatic anxiety scores decreased, alertness and sleep parameters improved, and ability to experience pleasure increased. In these secondary outcome measures, there were no significant differences between the treatment groups. Agomelatine was well-tolerated, with a lower incidence of adverse events than escitalopram. Agomelatine and escitalopram are efficacious in treating GAD patients with severe symptoms. (c) 2018 Elsevier B.V. and ECNP. All rights reserved