Prefeeding with omega-3 fatty acids suppresses inflammation following hemorrhagic shock.
BACKGROUND
Hemorrhagic shock followed by resuscitation stimulates an inflammatory response. This study tests the hypothesis that prefeeding with fish oil rich in ω-3 fatty acids (FAs) will attenuate that response.


METHODS
Male Sprague-Dawley rats (n = 60; 350 ± 30 g) were randomly but unequally assigned to 3 groups: sham (n = 12), control (n = 24), and fish oil (n = 24). In the fish oil group, rat chow was supplemented with fish oil (600 mg/kg/d, 25% ω-3 FA). Control and sham group diets were supplemented with corn oil. Under fluothane, hemorrhagic shock was induced, and arterial pressure was maintained at 25 to 30 mm Hg for 30 minutes. Resuscitation was carried out by giving 21 mL/kg lactated Ringer's solution and returning shed blood to the animal. Half of each group was killed at 30 minutes and at 4 hours postresuscitation. Liver samples were assayed for indicators of inflammation and heat shock protein 25 (Hsp25). Lung edema was measured.


RESULTS
All animals survived. At 30 minutes postresuscitation, expression of mRNA for inducible nitric oxide synthase (iNOS) was significantly elevated in the control group but normal in the fish oil group. At 4 hours, expression of mRNA for Hsp25 was significantly increased in the fish oil group. Lung edema index was significantly lower in the fish oil group than in either sham or control groups.


CONCLUSIONS
Fish oil prefeeding in a rodent model of hemorrhagic shock was associated with increased liver mRNA expression of Hsp25, reduced liver mRNA expression of iNOS, and decreased lung edema. These findings support the validity of the study hypothesis.
Yang
Rongjie
R
Department of Thoracic Surgery, Liaoning Province Cancer Hospital, Shenyang, People's Republic of China.
Harris
William S
WS
Vernon
Katherine
K
Thomas
Ann M
AM
Qureshi
Nilofer
N
Morrison
David C
DC
Van Way
Charles W
CW
D000818:Animals; D001803:Blood Transfusion; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D004487:Edema / Q000209:etiology / Q000517:prevention & control; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005395:Fish Oils / Q000494:pharmacology / Q000627:therapeutic use*; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006221:Halothane; D007249:Inflammation / Q000209:etiology / Q000517:prevention & control*; D007552:Isotonic Solutions / Q000627:therapeutic use; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008168:Lung / Q000187:drug effects*; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation / Q000379:methods; D000077331:Ringer's Solution; D012771:Shock, Hemorrhagic / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism
D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D055551:HSP27 Heat-Shock Proteins; C486114:Hspb1 protein, rat; D007552:Isotonic Solutions; D012333:RNA, Messenger; D000077331:Ringer's Solution; D052247:Nitric Oxide Synthase Type II; D006221:Halothane