Back to Search
Start Over
Equine insulin receptor and insulin-like growth factor-1 receptor expression in digital lamellar tissue and insulin target tissues.
- Source :
-
Equine veterinary journal [Equine Vet J] 2016 Sep; Vol. 48 (5), pp. 626-32. Date of Electronic Publication: 2015 Aug 21. - Publication Year :
- 2016
-
Abstract
- Reasons for Performing Study: Hyperinsulinaemia is implicated in the pathogenesis of endocrinopathic laminitis. Insulin can bind to different receptors: two insulin receptor isoforms (InsR-A and InsR-B), insulin-like growth factor-1 receptor (IGF-1R) and InsR/IGF-1R hybrid receptor (Hybrid). Currently, mRNA expression of these receptors in equine tissues and the influence of body type and dietary carbohydrate intake on expression of these receptors is not known.<br />Objectives: The study objectives were to characterise InsR-A, InsR-B, IGF-1R and Hybrid expression in lamellar tissue (LT) and insulin responsive tissues from horses and examine the effect of dietary nonstructural carbohydrate (NSC) on mRNA expression of these receptors in LT, skeletal muscle, liver and two adipose tissue (AT) depots of lean and obese ponies.<br />Study Design: In vivo experiment.<br />Methods: Lamellar tissue samples were evaluated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) for receptor mRNA expression (n = 8) and immunoblotting for protein expression (n = 3). Archived LT, skeletal muscle, liver and AT from lean and obese mixed-breed ponies fed either a low (~7% NSC as dry matter; 5 lean, 5 obese) or high NSC diet (~42% NSC as dry matter; 6 lean, 6 obese) for 7 days were evaluated by RT-qPCR to determine the effect of body condition and diet on expression of the receptors in different tissues. Significance was set at P≤0.05.<br />Results: Lamellar tissue expresses both InsR isoforms, IGF-1R and Hybrid. LT IGF-1R gene expression was greater than either InsR isoform and InsR-A expression was greater than InsR-B (P≤0.05). Obesity significantly lowered IGF-1R, InsR-A and InsR-B mRNA expression in LT and InsR-A in tailhead AT. High NSC diet lowered expression of all three receptor types in liver; IGF-1R and InsR-A in LT and InsR-A in tailhead AT.<br />Conclusions: Lamellar tissue expresses IGF-1R, InsR isoforms and Hybrids. The functional characteristics of these receptors and their role in endocrinopathic laminitis warrants further investigation.<br /> (© 2015 EVJ Ltd.)
- Subjects :
- Animal Feed analysis
Animal Nutritional Physiological Phenomena
Animals
Diet veterinary
Dietary Carbohydrates adverse effects
Foot Diseases veterinary
Gene Expression Regulation physiology
Horses
Obesity chemically induced
Obesity metabolism
Protein Isoforms
RNA, Messenger genetics
RNA, Messenger metabolism
Receptor, Insulin genetics
Horse Diseases metabolism
Insulin metabolism
Obesity veterinary
Receptor, IGF Type 1 metabolism
Receptor, Insulin metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 2042-3306
- Volume :
- 48
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Equine veterinary journal
- Publication Type :
- Academic Journal
- Accession number :
- 26095356
- Full Text :
- https://doi.org/10.1111/evj.12474