The effect of dietary vitamin E and beta-carotene on oxidation processes in the rat testis.
The effects of dietary vitamin E and beta-carotene were studied on enzymes involved in arachidonic acid metabolism and other related enzymes in the rat testis. Groups of rats were fed various soybean oil-based semi purified diets. Group 1 was fed a vitamin E-supplemented diet (+E - beta); Group 2 was fed a beta-carotene-supplemented diet (-E + beta); Group 3, the control group (-E - beta) was fed a vitamin E-deficient diet; and Group 4, the standard diet group (S), was fed vitamin E plus beta-carotene-standard diet. Soybean oxidized oil was added to the three diet groups - (+E - beta), (- E + beta) and (- E - beta), whereas the diet of S group contained non-oxidized oil. After 8 weeks rats were killed, blood and testis samples were collected for biochemical determinations. Vitamin E deficiency caused significant increase in testis thiobarbituric acid value and activities of testis NADPH oxidase, testis 15-lipoxygenase and in plasma pyruvate kinase. In contrast, significant decreases were observed in activity of testis prostaglandin synthetase, compared with antioxidant-supplemented diet groups. We also found a significant increase in 15-lipoxygenase activity in (- E + beta) diet group, compared with (- E - beta) diet group. Fatty acid analysis of testis parenchyma indicated decrease in palmitate (16:0) and arachidonate (20:4(n - 6)), and increase in oleate (18:1(n-6)) linoleate (18:2(n - 6)) and linolenate (18:3(n - 3)), when compared (-E - beta) diet group with vitamin E-supplemented diet groups. The results suggest that dietary vitamin E has a role in both enzymatic and non-enzymatic peroxidation of polyunsaturated fatty acids in the testis.
Lomnitski
L
L
Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Bergman
M
M
Schön
I
I
Grossman
S
S
D000818:Animals; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism; D002338:Carotenoids / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D019255:NADPH Oxidases; D010084:Oxidation-Reduction; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism; D011770:Pyruvate Kinase / Q000097:blood; D051381:Rats; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013858:Thiobarbiturates; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*; D019207:beta Carotene
D005231:Fatty Acids, Unsaturated; D011453:Prostaglandins; D013858:Thiobarbiturates; D019207:beta Carotene; D014810:Vitamin E; D002338:Carotenoids; D008315:Malondialdehyde; D001093:Arachidonate 15-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D011770:Pyruvate Kinase; C029684:thiobarbituric acid