Metabolic responsiveness of different size adipocytes to fasting and refeeding in the pig.
The effects of fasting (F) and fasting-refeeding (FR) on [U-14C]glucose and [1-14C]palmitate metabolism were examined in pig middle subcutaneous (MSQ) adipocytes fractionated into 20--63, 63--102 and 102--153 microns diameter ranges. Fasting caused a similar decrease in de novo glyceride fatty acid (GFA) and glyceride-glycerol (GG) synthesis from glucose among adipocytes of different size. After refeeding for 2 days, glucose metabolism significantly increased in all fractions, however, the increase did not reach non-fasting levels. There was a disparate increase in glucose metabolism among adipocyte fractions after refeeding. Adipocytes 102--153 microns in diameter had a larger increase in glucose metabolism than smaller adipocytes. Fasting suppressed palmitate esterification rates in 20--63 and 63--102 microns fractions. Esterification by adipocyted 102--153 microns in diameter was not diminished after fasting. An "overshoot" in esterification by adipocytes 63--102 and 102--153 microns in diameter relative to control adipocytes was observed after refeeding; no "overshoot" occurred in 20--63 microns adipocytes. These results indicate that adipocytes of different size have markedly different capacities for substrate utilization after F or FR as well as different metabolic adaptations to F or FR.
D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002369:Castration; D002452:Cell Count; D005215:Fasting; D005227:Fatty Acids / Q000096:biosynthesis; D005502:Food; D005947:Glucose / Q000378:metabolism; D005989:Glycerides / Q000096:biosynthesis; D005990:Glycerol / Q000096:biosynthesis; D008055:Lipids / Q000096:biosynthesis*; D008297:Male; D010168:Palmitates / Q000378:metabolism; D012867:Skin; D013552:Swine / Q000378:metabolism*
D005227:Fatty Acids; D005989:Glycerides; D008055:Lipids; D010168:Palmitates; D005947:Glucose; D005990:Glycerol