Liver and skeletal muscle lipids have differing fatty acid profiles in short-gut rats fed via parenteral nutrition.
BACKGROUND
In short-gut rats, we showed marked abnormalities in plasma lipid fatty acids using parenteral nutrition (PN) with lipid vs sham surgery rats. This suggests that either sensing or metabolism of parenteral lipid is abnormal in malabsorption. The goal of this study was to determine fatty acid profiles in skeletal muscle and liver in short-gut rats treated with PN compared with sham rats.


METHODS
Sprague-Dawley rats underwent laparotomy and massive small bowel resection (or sham surgery). Rats (n = 32, 16 sham, 16 short gut) were randomly assigned to PN with lipid or fat-free PN. After 5 days, weight loss was similar in all groups, and mixed hindlimb skeletal muscle and liver were biopsied.


RESULTS
We found marked differences between liver and skeletal muscle. In livers of short-gut animals, 22:4omega6, 22:5omega6, and 22:6omega3 were higher (all p < .05) than in sham. In skeletal muscle, short gut had no effect on fatty acid profiles. In liver, fat-free PN led to significant increases in 20:3omega6, 22:4omega6, 22:5omega6, 20:3omega9, 20:5omega3, 22:6omega3, and triene/tetraene ratio (all p < .05) compared with feeding PN with lipid, irrespective of short gut. In muscle, levels of the distal long-chain fatty acid metabolites and triene/tetraene ratio were minimally affected by nutrition. Serum glucose and insulin concentrations were similar in all 4 groups.


CONCLUSIONS
Both the presence of short gut and type of PN led to increases in distal metabolites of fatty acids on omega:3 and omega:6 pathway in liver phospholipids but not in skeletal muscle during short-term PN feeding in rats.
McCowen
Karen C
KC
Beth Israel Deaconess Medical Center, Boston, Massachusetts.
Ling
Pei-Ra
PR
Ollero
Mario
M
Maykel
Justin A
JA
Blanco
Paola G
PG
Bistrian
Bruce R
BR
D000818:Animals; D005217:Fat Emulsions, Intravenous / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000032:analysis / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008099:Liver / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000378:metabolism; D010288:Parenteral Nutrition; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012778:Short Bowel Syndrome / Q000378:metabolism / Q000628:therapy
D005217:Fat Emulsions, Intravenous; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D010743:Phospholipids