Psychosocial stress, catecholamines, and essential fatty acid metabolism in rats

• Published in: Proceedings of the Society for Experimental Biology and Medicine Vol. 205; no. 1; p. 56
• Main Authors: Mills, D.E, Huang, Y.S, Narce, M, Poisson, J.P
• Format: Journal Article
• Language: English
• Published: United States 01.01.1994
• Subjects: ACIDE LINOLEIQUE; ACIDO LINOLEICO; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; ADRENALINE; Analysis of Variance; Animals; Arachidonic Acid - blood; Arachidonic Acid - metabolism; COMPLEMENT ALIMENTAIRE; ENZIMAS; ENZYME; EPINEFRINA; Epinephrine - pharmacology; ESTRES; Fatty Acid Desaturases - metabolism; Fatty Acids, Essential - deficiency; Fatty Acids, Essential - metabolism; Female; HIPERTENSION ARTERIAL; HYPERTENSION; Kinetics; Linoleic Acid; Linoleic Acids - blood; Linoleic Acids - metabolism; Linoleoyl-CoA Desaturase; Liver - drug effects; Liver - metabolism; Male; METABOLISME DES LIPIDES; METABOLISMO DE LIPIDOS; Microsomes, Liver - enzymology; Phospholipids - blood; Phospholipids - metabolism; RAT; RATA; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Rats, Sprague-Dawley; Safflower Oil - pharmacology; Social Isolation; STRESS; Stress, Psychological - metabolism; SUPLEMENTOS; Time Factors; Triglycerides - blood; Triglycerides - metabolism
• ISSN: 0037-9727; 1525-1373
• DOI: 10.3181/00379727-205-43677

To examine the effects of psychosocial stress and the "stress hormone," epinephrine, on essential fatty acid metabolism in rats, two studies were conducted. In the first, the effects of four weeks of (i) social isolation and (ii) group housing (control) on liver microsomal delta 6 and delta 5 n-6 desaturase activity were studied in group-reared male normotensive (Wistar Kyoto) and spontaneously hypertensive (SHR) rats (n = 5/group). The second study examined the effects of acute ip epinephrine (0.0, 1.0, 2.0, and 4.0 mg/kg) 6 hr prior to and following an ig dose (4 g/kg) of safflower oil (rich in 18:2n-6, LA) on plasma and liver LA, 20:4n-6 (AA), and LA/AA ratios in adult essential fatty acid deficient Sprague-Dawley rats (n = 6/group). In the first experiment, isolation stress significantly inhibited the activity of delta 6 (P 0.05) and delta 5 (P 0.01) desaturase in the normotensive rats and of 45 desaturase in the SHR (P 0.05). in the second study, epinephrine increased plasma and liver LA at doses 1.0 and 2.0 mg/kg in most of the fractions examined, and suppressed AA levels. The response of the LA/AA ratio to epinephrine varied between tissues and among lipid fractions, but increased this ratio at the moderate doses (2.0-4.0 mg/kg) of epinephrine in most cases. These data suggest that psychosocial stressors are capable of inhibiting the rate limiting steps of essential fatty acid metabolism and that this response is more pronounced in the SHR than in the Wistar Kyoto. They also suggest that epinephrine is capable of altering the in vivo metabolism of essential fatty acids in the rat