Changes in liver fatty acid unsaturation after partial hepatectomy in the rat

Abstract

The purpose of this study was to assess changes in the degree of fatty acid unsaturation in rat liver after partial hepatectomy. This is the first study in which liver fatty acid unsaturation has been analyzed over a long period of regeneration until day 28 after operation. The relationship between changes in unsaturation and fatty acid composition in the regenerating liver were also investigated in this study. Proton nuclear magnetic resonance spectroscopy revealed significantly elevated levels of unsaturation with a maximum on day 5 after partial hepatectomy, compared with untreated controls (11.72+/-0.55 vs. 11.05+/-0.26%, P < 0.05). No significant changes in unsaturation were found in day 1 regenerating liver, which is rich in absolute amounts of fatty acids. Based on gas-liquid chromatography, the relative amounts of oleic acid (18:1n-9) and linoleic acid (LA; 18:2n-6) were increased, while polyunsaturated fatty acids such as arachidonic acid (20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) were decreased on day 1. On the other hand, on day 5 of regeneration, while most fatty acids were returning to their preoperative control levels, only DHA was higher than the control value (7.69+/-0.58 vs. 5.57+/-0.37%, P < 0.001). The high levels of unsaturation on day 5 were found to be partly due to the increase in DHA. The findings suggest that some significant signals are transmitted during the regeneration process owing to alterations in the membrane structure by the high levels of fatty acid unsaturation and the increase in DHA levels on day 5 after partial hepatectomy.

Hepatic Regeneration and Reno-Protection by Fish oil, <i>Nigella sativa</i> Oil and Combined Fish Oil/<i>Nigella sativa</i> Volatiles in CCl₄ Treated Rats

“…These authors suggested that some significant signals are transmitted during the regeneration process owing to alterations in the membrane structure by the high levels of fatty acid after partial hepatectomy. In the present study; the three different oils treatment produced significant increase in both oleic and linoleic acid except for linoleic acid in case of fish oil compared to normal rats reflecting the possible increase in regeneration process as previously reported 50 . The fatty acid profile in liver was rarely studied during intake of ω-3 or ω-6 rich oils or even after treatment with CCl 4 ; the scarce studies found could not explain the mechanism by which alteration in hepatic fatty acids profile occur.…”

“…CCl 4 treatment provoked fatty metamorphosis in liver 49 . It was also reported that oleic acid and linoleic acid were increased in liver tissue after partial hepatoectomy 50 . These authors suggested that some significant signals are transmitted during the regeneration process owing to alterations in the membrane structure by the high levels of fatty acid after partial hepatectomy.…”

Lipid overloading during liver regeneration causes delayed hepatocyte DNA replication by increasing ER stress in mice with simple hepatic steatosis

“…Several studies have reported the changes of FFA components after PHx. These authors described the roles of unsaturated FFAs as signal transducers, but did not mention saturated FFAs [34, 35]. Recently, many studies have reported the cytotoxic effects of saturated FFAs, such as stearic acid and palmitic acid, and the cytoprotective effects of unsaturated FFAs, such as oleic acids and linoleic acid.…”

Effects of docosahexaenoic acid on annular lipid fluidity of the rat bile canalicular plasma membrane

“…e-mail: michio1@shimane-med.ac.jp membrane proteins may thus help in unveiling the effects of annular fluidity on membrane-bound proteins. DHA has been shown to accumulate in the regenerating liver after partial hepatectomy (17), a postoperative condition associated with alterations in membrane fluidity (18). Dietary fatty acids can influence the physical state and the function of membrane-bound enzymes such as 5 Ј -nucleotidase (19) and Na ϩ ,K ϩ -ATPase (20).…”