Background and objective
Omega-3 fatty acids, such as α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are polyunsaturated fatty acids (PUFA) that have long been associated with anti-inflammatory activity and general benefit toward human health. Over the last decade, the identification of a family of cell-surface G protein-coupled receptors that bind and are activated by free-fatty acids, including omega-3 fatty acids, suggests that many effects of PUFA are receptor-mediated. One such receptor, free-fatty acid receptor-4 (FFAR4), previously described as GPR120, has been shown to modulate anti-inflammatory and insulin-sensitizing effects in response to PUFA such as ALA and DHA. Additionally, FFAR4 stimulates secretion of the insulin secretagogue glucagon like peptide-1 (GLP-1) from the GI tract and acts as a dietary sensor to regulate energy availability. The aim of the current study was to assess the effects of dietary omega-3 fatty acid supplementation on FFAR4 expression in the rat colon.
Methods
Sprague-Dawley rats were fed control soybean oil diets or alternatively, diets supplemented with either fish oil, which is enriched in DHA and EPA, or flaxseed oil, which is enriched in ALA, for seven weeks. GLP-1 and blood glucose levels were monitored weekly and at the end of the study period, expression of FFAR4 and the inflammatory marker TNF–α was assessed.
Results
Our findings indicate that GLP-1 and blood glucose levels were unaffected by omega-3 supplementation, however, animals that were fed fish or flaxseed oil-supplemented diets had significantly heightened colonic FFAR4 and actin expression, and reduced expression of the pro-inflammatory cytokine TNF-α compared to animals fed control diets.
Conclusions
These results suggest that similar to ingestion of other fats, dietary intake of omega-3 fatty acids can alter FFAR4 expression within the colon.
The POAG optic neuropathies result in optic disk damage and visual field loss. Ophthalmic medication therapy retards glaucoma progression, but many older patients require multiple medications to preserve vision and quality of life. An agent from the ophthalmic prostaglandin analog class is used as initial therapy in current practice because of the convenience of once-a-day administration and lower incidence of systemic side effects and slightly increased efficacy compared with other available ophthalmic medication classes. The other ophthalmic medication classes used in clinical practice include the beta-adrenergic blocking agents, the alpha-2 adrenergic agonists, and the carbonic anhydrase inhibitors. Proper ophthalmic eye-drop administration and medication adherence are imperative for preserving vision in POAG. Selective laser trabeculoplasty is a viable alternative to ophthalmic medications either initially or if a patient experiences ocular or systemic side effects from medication therapy. A modified prostaglandin analog was approved by the Food and Drug Administration in November 2017; its role in clinical practice is still evolving.
Stress during times of rapid development is a risk factor for Major Depressive Disorder, a mood disorder that disproportionately affects women. We developed an adolescent chronic restraint stress (aCRS) protocol using female rats to address the impact of adolescent stress on female adult depressive-like behavior. Animals were divided into 4 treatment groups: not restrained:saline (NRSAL), not restrained:desipramine (NRDES), restrained:saline (RSAL), and restrained:desipramine (RDES). NRSAL and NRDES rats were housed in a separate colony room from RSAL and RDES rats. All animals were weighed and handled daily. Beginning postnatal day (PND) 34(±1), RSAL and RDES rats were restrained for 1 hour daily for 14 consecutive days. Beginning PND 55(±1), NRDES and RDES rats were given subcutaneous desipramine (5 mg/kg), which served as a positive control, daily for 14 consecutive days. During that same time period, NRSAL and RSAL rats were given subcutaneous saline daily. aCRS (RSAL and RDES) rats showed significantly attenuated weight gain compared with nonrestrained (NRSAL and NRDES) rats during the restraint period. Weight gain normalized after the final restraint session. Behavioral testing took place PND 68-69(±1), and included open field testing, the elevated plus maze, locomotor activity, and the forced swim test (FST). RSAL rats showed significantly more immobility in the FST versus all other groups, indicating depressive-like behavior. No differences between groups were observed in the other behavioral measures. These results indicate that aCRS elicits depressive-like behavioral characteristics in adult female rats without increasing anxiety-like behaviors. (PsycINFO Database Record
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