P1.37. EFFECTS OF CHRONIC MILD STRESS AND ESCITALOPRAM ON GLUCAGON-LIKE PEPTIDE-1 AND FUNCTIONALLY RELATED PROTEINS IN THE FRONTAL CORTEX OF RATS.
Kinga Dyndał1, Magdalena Sowa-Kućma2,3, Natalia Gałka2, Mariusz Papp4, Patrycja Pańczyszyn-Trzewik2
1 Students Science Club "NEURON", Faculty of Medicine, Collegium Medicum, University of Rzeszów, Rzeszow, Poland
2 Department of Human Physiology, Faculty of Medicine, Collegium Medicum, University of Rzeszów, Rzeszow, Poland
3 Centre for Innovative Research in Medical and Natural Sciences, Faculty of Medicine, Collegium Medicum, University of Rzeszów, Rzeszow, Poland
4 Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland
INTRODUCTION: Depressive disorders are associated with neurobiological alterations in the brain involving both serotonergic signaling and neurotrophic factors regulating neuronal plasticity [Pannu et al.,2023;Yang et al.,2020]. Recently, gut-derived peptides such as glucagon-like peptide-1 (GLP-1) have gained attention for their potential role in brain function modulation [McIntyre et al.,2025].
AIM(S): To investigate the effects of chronic mild stress (CMS;animal model of depression) and escitalopram (ESC; a selective serotonin reuptake inhibitor) treatment on the levels of GLP-1 and functionally related proteins (GLP-1R, BDNF, TrkB) in the frontal cortex (FCx) of rats.
METHOD(S): Brain samples (FCx) were obtained from rats subjected to the CMS procedure (7 weeks;Stress NaCl) and 35-day escitalopram treatment (10 mg/kg;Stress ESC). Appropriate non-stressed control groups were included (CTR NaCl;CTR ESC) in this study.
GLP-1 concentration was measured using a commercial ELISA kit. Protein levels of GLP-1R, BDNF, TrkB were assessed by Western blot analysis. Statistical analysis was performed using two-way ANOVA in GraphPad PRISM v10.0.
RESULTS: The CMS procedure significantly reduced GLP-1 concentration in rats’ FCx (p<0.05; CTR NaCl vs. Stres NaCl), while ESC10 administration reversed these changes (p<0.01; Stres NaCl vs. Stress ESC). Two-way ANOVA revealed significant effect of drug (F1,19=5.505, p=0.0367), no effect of stress (F1,19=0.04, p=0.8491) and significant interaction (F1,19=16.51, p=0.0006). These changes were accompanied by reductions in GLP-1R (p=0.004), BDNF (p=0.0156), and a trend toward decreased TrkB (p=0.0561) in stressed animals, which were partially reversed following escitalopram administration.
CONCLUSIONS: Our findings suggest that chronic stress and escitalopram may modulate neuropeptidergic and neurotrophic signaling in the frontal cortex, with alterations in GLP-1, GLP-1R, BDNF, TrkB levels potentially linking stress pathophysiology to antidepressant action.
FINANCIAL SUPPORT: The study was partially supported by grants from the National Science Centre (contracts: UMO-2016/21/B/NZ7/01623 to M. Sowa-Kucma) and by fund of the University of Rzeszow (grant: NIW/8/2024).