Abstract
Although the seasonal shift from carbohydrate to lipid metabolism in hibernators is well established, a comprehensive study of lipid regulation in one species is lacking. To address this we studied triglyceride (TG) and lipoprotein metabolism in spring (SPR), summer (SUM) and hibernating (HIB) 13‐lined ground squirrels (5–6 per group). Plasma TGs are carried in VLDL particles in all seasons. There are no differences among the groups in ApoB mRNA in liver and gut or ApoB protein in liver and plasma. Fasting decreases plasma TGs 2‐fold in SPR (p<0.05), but not in SUM. Plasma TGs are lower in torpid HIB (76.7±43.9 mg/dl) than interbout arousal (IBA) HIB (178.0±17.4 mg/dl), and both are less than SUM (278.2±44.4 mg/dl) (P<0.05). Plasma free fatty acids (FFAs) are highest in torpid HIB, equal in SUM and IBA HIB (P<0.001), and are not affected by fasting in SPR or SUM. Liver TGs are higher in torpid HIB than in SPR or IBA HIB (P<0.05), but liver FFAs are highest in torpid HIB (P<0.05). White adipose tissue (WAT) TGs do not vary among states, but WAT FFAs are lower in torpid HIB than SUM (P<0.05). mRNA levels of the TG synthesis enzymes MGAT2 and DGAT2 are greater in HIB than SUM (P<0.05). The results provide insight into how hibernating species regulate synthesis and distribution of lipids throughout the body during their annual cycle of feeding and fasting.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
