INHIBITORY EFFECT OF LINOLEIC-ACID ON CHAIN ELONGATION AND DESATURATION OF 18 2 C,T-ISOMERS IN LACTATING AND NEONATAL RATS/

Citation
Ky. Kwan et al., INHIBITORY EFFECT OF LINOLEIC-ACID ON CHAIN ELONGATION AND DESATURATION OF 18 2 C,T-ISOMERS IN LACTATING AND NEONATAL RATS/, Lipids, 33(4), 1998, pp. 409-416
Citations number
34
Categorie Soggetti
Biology,"Nutrition & Dietetics
Journal title
LipidsACNP
ISSN journal
00244201
Volume
33
Issue
4
Year of publication
1998
Pages
409 - 416
Database
ISI
SICI code
0024-4201(1998)33:4<409:IEOLOC>2.0.ZU;2-Z
Abstract
The previous studies showed that dietary 18:2 c,t isomers could be cha in-elongated and desaturated to produce unusual 20:4 isomers. The pres ent study was undertaken to determine the minimal amount of 18:2n-6 re quired to suppress the chain elongation and desaturation of 18:2 c,t i somers in the lactating and neonatal rats when animals were fed 15% pa rtially hydrogenated canola oil diet containing 1.72% energy as 18:2 c ,t isomers and varying amounts of free 18:2n-6. These diets induced ma rginal essential fatty acid (EFA) deficiency states (0.56% energy 18:2 n-6) to EFA adequacy (2.56% energy 18:2n-6). After feeding for 50 d, t he female animals were mated with males by overnight pairing. After co nception, the lactating rats were killed, together with one pup from e ach dam, at term and day 26 of lactation. Two unusual 20:4 isomers in both maternal and neonatal liver phospholipids were identified as 20:4 Delta 5c,8c, 11c,14t and 20:4 Delta 5c,8c,11c,15t, which were derived from 18:2 Delta 9c,12t and 18:2 Delta 9c,13t, respectively. The resul ts showed that 18:2n-6 at about 2.0% of total energy in maternal diet was required to block the production of 20:4 Delta 5c,8c,11c,14t and 2 0:4 Delta 5c,8c,11c,15t in the maternal liver, whereas 18:2n-6 at abou t 2.5% of total energy in maternal diet was required to suppress produ ction of these unusual 20:4 isomers in the neonatal liver.