Prozac Research Today is a free monthly online journal that collates and summarizes the latest research about Prozac, including details on depression, side-effects, withdrawal, alternatives.

Inhibition of egg production in zebrafish by fluoxetine and municipal effluents: a mechanistic evaluation.

Lister A, Regan C, Van Zwol J, Van Der Kraak G

Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.

This study explored the impact of nominal concentrations of ethinylestradiol (EE(2); 10ng/L), fluoxetine (FLU; 0.32, 3.2, 32microg/L), and 1-50% treated municipal effluent on reproduction and liver function in sexually mature female zebrafish over a 7-day period. Compared with the control groups, FLU (32microg/L) and 50% effluent treatment significantly reduced the average eggs spawned by approximately 4.5 and 2 fold, respectively. FLU also decreased ovarian levels of 17beta-estradiol (E(2)) without affecting the gonadosomatic indices of the fish. The expression of ovarian genes involved in the production of prostaglandins, steroid biosynthesis, and gonadotropin receptors were quantified to determine a potential mechanism underlying the reduced egg production in FLU and effluent exposed fish. Quantitative real-time PCR analysis determined that ovarian aromatase, follicle stimulating hormone receptor (FSHr), and luteinizing hormone receptor (LHr) gene expression were significantly reduced by FLU suggesting that disruptions to the synthesis of ovarian steroids and the actions of gonadotropins may underlie the negative influence of FLU on ovarian E(2) and spawning levels. Potential mechanisms involved in the modest effects of the effluent on reproduction remain unknown, but the elevated levels of total ammonia and nitrite in the 50% effluent treatment groups compared with the other treatments should not be discounted. Liver expression of CYP3A65 was significantly induced by all treatments of effluent, while EE(2) caused a reduction in the expression levels of CYP1A1, PXR, and CYP3A65. The results of the present study suggest that SSRI may disrupt reproductive functioning at concentrations greater than those found in receiving environments; yet, more research is warranted into to the possible effects of low levels of synthetic estrogens on liver function in exposed fish, particularly the PXR-CYP3A pathway.

Published 30 November 2009 in Aquat Toxicol, 95(4): 320-9.
Full-text of this article is available online (may require subscription).

Articles on Prozac published 20 October 2009:

Effects of olanzapine, fluoxetine and olanzapine/fluoxetine on creatine kinase activity in rat brain.   Brain Res Bull, 80(6): 337-40.

Recently, a fixed combination of the atypical antipsychotic olanzapine and the serotonin selective reuptake inhibitor (SSRI) fluoxetine has been approved in the US for the treatment of bipolar I depression. In this work, we evaluated the effect of acute and chronic administration of fluoxetine, olanzapine and the combination of fluoxetine/olanzapine on creatine kinase (CK) activity in the brain of rats. For acute treatment, adult male Wistar rats received one single injection of olanzapine (3 ... [Abstract] [Full-text]

Articles on Prozac published 2 October 2009:

The Treatment for Adolescents With Depression Study (TADS): outcomes over 1 year of naturalistic follow-up.   Am J Psychiatry, 166(10): 1141-9.

OBJECTIVE: The Treatment for Adolescents With Depression Study (TADS) evaluates the effectiveness of fluoxetine, cognitive-behavioral therapy (CBT), and their combination in adolescents with major depressive disorder. The authors report effectiveness outcomes across a 1-year naturalistic follow-up period. METHOD: The randomized, controlled trial was conducted in 13 academic and community sites in the United States. Stages I, II, and III consisted of 12, 6, and 18 weeks of acute, consolidation, ... [Abstract] [Full-text]

Clinical messages from the Treatment for Adolescents With Depression Study (TADS).   Am J Psychiatry, 166(10): 1118-23.

OBJECTIVE: The purpose of this report was to summarize the key clinical messages from the Treatment for Adolescents with Depression Study (TADS). METHODS: TADS is a National Institute of Mental Health (NIMH)-funded randomized controlled trial designed to evaluate the relative effectiveness of fluoxetine, cognitive-behavioral therapy (CBT), and the combination of fluoxetine plus CBT across acute treatment, maintenance treatment, and naturalistic follow-up periods among adolescents with major ... [Abstract] [Full-text]

Articles on Prozac published 28 September 2009:

Effects of chronic intracerebroventricular 3,4-methylenedioxy-N-methamphetamine (MDMA) or fluoxetine on the active avoidance test in rats with or without exposure to mild chronic stress.   Behav Brain Res, 205(1): 259-64.

In despite the similarity of mechanisms of action between both selective serotonin reuptake inhibitors (SSRI) and MDMA (main compound of "Ecstasy") there are relatively few reports on the effects of the later on animal models of depression. There are many animal models designed to create or to assess depression. Mild chronic stress (MCS) is a procedure designed to create depression. MCS includes the chronic exposure of the animal to several stressors. After that, rats show behavioural ... [Abstract] [Full-text]

Articles on Prozac published 15 September 2009:

Randomized, controlled clinical trial of the efficacy of fluoxetine for treatment of compulsive disorders in dogs.   J Am Vet Med Assoc, 235(6): 705-9.

OBJECTIVE: To evaluate efficacy of fluoxetine hydrochloride for treatment of compulsive disorders in dogs. DESIGN: Randomized, controlled clinical trial. ANIMALS: 63 dogs with compulsive disorders. PROCEDURES: The diagnosis was confirmed on the basis of analysis of videotapes of the dogs' behavior by 3 veterinary behaviorists, results of physical examination and clinicopathologic testing, and, when necessary, telephone interviews with owners. Dogs were randomly assigned to treatment with ... [Abstract] [Full-text]

Articles on Prozac published 3 September 2009:

Fluoxetine and norfluoxetine revisited: new insights into the electrochemical and spectroscopic properties.   J Phys Chem A, 113(36): 9934-44.

The extent to which humans and wildlife are exposed to the vast array of anthropogenic chemicals and their degradation products, along with related naturally occurring compounds, is nowadays an important issue. The study of the physical-chemical properties of the compounds and/or degradation products is an important subject because some of them are intrinsically related to its resistance to degradation and/or bioaccumulation. Accordingly, the study of the electrochemical behavior of the ... [Abstract] [Full-text]

Articles on Prozac published 2 September 2009:

Imbalance between pro- and anti-inflammatory cytokines, and between Th1 and Th2 cytokines in depressed patients: the effect of electroacupuncture or fluoxetine treatment.   Pharmacopsychiatry, 42(5): 182-8.

BACKGROUND: An increase in inflammatory response and an imbalance between T-helper (Th) 1 and 2 functions have been implicated in major depression. The aims of the present study were to 1) study the relationship between pro- and anti-inflammatory cytokines and between Th1 and Th2 produced cytokines in depressed patients and 2) evaluate and compare the effect of treatments with electroacupuncture (EA) and fluoxetine on these cytokines. METHODS: 95 outpatients with major depressive disorder were ... [Abstract] [Full-text]

Ondansetron and fluoxetine reduce sleep apnea in mice lacking monoamine oxidase A.   Respir Physiol Neurobiol, 168(3): 230-8.

Prospective clinical trials addressing the role of serotonin (5-HT) in sleep apnea have indicated that the 5-HT uptake inhibitor fluoxetine is beneficial to some patients with obstructive apnea, whereas the 5-HT(3) receptor antagonist ondansetron seems of little value despite its efficacy in rat and dog models of sleep apnea (central and obstructive). Here, we examined the effect of these drugs in transgenic mice lacking monoamine oxidase A (Tg8), which exhibit approximately 3-fold higher rates ... [Abstract] [Full-text]

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