Format

Send to

Choose Destination
Microsc Res Tech. 2015 Aug;78(8):707-14. doi: 10.1002/jemt.22528. Epub 2015 Jun 12.

The orexinergic system in rainbow trout Oncorhynchus mykiss and its regulation by dietary lipids.

Author information

1
Department of Science and Technologies, University of Sannio, Benevento, 82100, Italy.
2
School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria, Australia.
3
Institute of Nutrition (ISA), Avellino, 83100, Italy.

Abstract

In this study, we report the distribution of orexin A (OXA), orexin B (OXB), and orexin receptor (OX2R) immunoreactive (ir) cells in the hypothalamus and gastrointestinal tract of Oncorhynchus mykiss fed diets with different dietary fatty acid compositions. Trout were fed five iso-energetic experimental diets containing fish oil, or one of four different vegetable oils (olive, sunflower, linseed, and palm oils) as the added dietary lipid source for 12 weeks. OXA, OXB, and OX2R immunoreactive neurons and nervous fibers were identified in the lateral and ventro-medial hypothalamus. OXA, OXB, and OX2R ir cells were found in the mucosa and glands of the stomach and in the mucosa of both the pyloric cecae and intestine. OX2R ir cells were localized in the mucosa layer of both the pyloric cecae and intestine. These immunohistochemical (IHC) results were confirmed via Western blotting. Antibodies against preproorexin (PPO) crossreacted with a band of ∼16 kDa in the hypothalamus, stomach, pyloric cecae, and intestine. Antibodies against OX2R crossreacted with a band of ∼38 kDa in the hypothalamus, pyloric cecae, and intestine. The presence and distribution of OXA, OXB, and OX2R ir cells in the hypothalamus and gastrointestinal tract did not appear to be affected by dietary oils. The presence of orexin system immunoreactive cells in the stomach, pyloric cecae, and intestine of rainbow trout, but not in the enteric nervous system, could suggest a possible role of these peptides as signaling of gastric emptying or endocrine modulation, implying a main local action played by orexins.

KEYWORDS:

gastrointestinal tract; hypothalamus; orexin A; orexin B; orexin receptor; prepro-orexin; rainbow trout

PMID:
26096763
DOI:
10.1002/jemt.22528
[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center