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Plasma Ascorbic Acid (plasma + ascorbic_acid)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Dietary vitamin E requirement of the red drum Sciaenops ocellatus

AQUACULTURE NUTRITION, Issue 3 2009
L.I. PENG
Abstract A 12-week feeding trial was conducted to establish the minimum dietary vitamin E requirement of juvenile red drum by broken-line regression analysis. The semi-purified basal diet was supplemented with 10, 20, 30, 40, 60 or 80 IU vitamin E kg,1 as all-rac -,-tocopheryl acetate. Juvenile red drum were conditioned by feeding the basal diet for 8 weeks prior to the feeding trial to reduce whole-body vitamin E levels. Then, fish initially averaging 12.2 ± 0.4 g fish,1 (mean ± SD) were fed the experimental diets at a rate approaching apparent satiation for 12 weeks. Weight gain and feed efficiency responses of fish fed diets were significantly (P < 0.01) altered by the level of vitamin E supplementation but not strictly in a dose-dependent manner. Vitamin E concentrations in liver and plasma also were significantly (P < 0.001) influenced by dietary vitamin E level. Plasma ascorbic acid in fish fed the basal diet tended (P = 0.066) to be lower than in fish fed diets containing the various levels of vitamin E. In addition, fish fed the basal diet showed edema in the heart, while fish fed all other diets were normal. Fish fed 60 or 80 IU all-rac -,-tocopheryl acetate kg,1 diet had significantly higher respiratory burst of head kidney macrophages than fish fed all other diets, although dietary effects on hematocrit and neutrophil oxidative radical production were not significant. The minimum dietary vitamin E requirement of juvenile red drum was established based on broken-line regression of liver thiobarbituric acid reactive substances to be 31 mg all-rac -,-tocopheryl acetate kg,1 diet. [source]

Relationship between seminal ascorbic acid and sperm DNA integrity in infertile men

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 6 2006
Gyun Jee Song
Summary Ascorbic acid has recently been reported to protect sperm DNA from the damage induced by exogenous oxidative stress in vitro. But, there is no report on seminal ascorbic acid and sperm DNA fragmentation in infertile men. In this study, we asked whether sperm DNA damage correlates with seminal ascorbic acid levels. Sperm DNA fragmentation index (DFI) was analysed in 75 men by flow cytometry after acridine orange staining. We also measured the levels of seminal plasma ascorbic acid and total antioxidant capacity. Abnormal sperm DNA integrity (DFI , 30%) was observed in 12% of the patients with normal semen parameters and in 52% of the patients with abnormal semen parameters. There were significant correlations between the level of DFI and conventional semen parameters including sperm count, motility and morphology (r = ,0.29, ,0.55 and ,0.53 respectively; p < 0.05). Seminal ascorbic acid level was significantly lower in the patients with leucospermia than the patient with normal semen parameters. Interestingly, a significantly greater percentage of men with abnormal DFI were observed in the patients with low levels of seminal ascorbic acid compared with those with normal or high levels of ascorbic acid (59% vs. 33%, p < 0.05). Men with insufficient seminal ascorbic acid frequently have sperm DNA damage. [source]

Effect of smoking on seminal plasma ascorbic acid in infertile and fertile males

ANDROLOGIA, Issue 6 2006
T. Mostafa
Summary This work aimed to assess the relationship of seminal ascorbic acid levels with smoking in infertile males. One hundred and seventy men were divided into four groups: nonobstructive azoospermia [NOA: smokers (n = 20), nonsmokers (n = 20)]; oligoasthenozoospermia [smokers (n = 30), nonsmokers (n = 20)]; asthenozoospermia [smokers (n = 20), nonsmokers (n = 20)] and normozoospermic fertile men [smokers (n = 20), nonsmokers (n = 20)]. The patients underwent medical history, clinical examination, conventional semen analysis and estimation of ascorbic acid in the seminal plasma calorimetrically. There was a significant decrease in the mean seminal plasma ascorbic acid levels in smokers versus nonsmokers in all groups (mean ± SD; 6.03 ± 2.18 versus 6.62 ± 1.29, 7.81 ± 1.98 versus 9.44 ± 2.15, 8.09 ± 1.98 versus 9.95 ± 2.03, 11.32 ± 2.15 versus 12.98 ± 12.19 mg dl,1 respectively). Fertile subjects, smokers or not, demonstrated significant higher seminal ascorbic acid levels than any infertile group. Seminal plasma ascorbic acid in smokers and nonsmokers was correlated significantly with sperm concentration (r = 0.59, 0.60, P < 0.001), sperm motility (r = 0.65, 0.55, P < 0.001) and negatively with sperm abnormal forms per cent (r = ,0.53, ,0.50, P < 0.001). Nonsignificant correlations were elicited with semen volume (r = 0.2, 0.09) or liquefaction time (r = 0.03, 0.06). It is concluded that seminal plasma ascorbic acid decreased significantly in smokers and infertile men versus nonsmokers and fertile men, and is significantly correlated with the main sperm parameters: count, motility and normal morphology. Also, cigarette smoking is associated with reduced semen main parameters that could worsen the male fertilizing potential, especially in borderline cases. [source]