0000000000117461
AUTHOR
Jorge Ten
Dietary antioxidant supplementation did not affect declining sperm function with age in the mouse but did increase head abnormalities and reduced sperm production
The present study aims to ascertain whether dietary administration of a mixture of vitamins C and E may prevent the negative effects of paternal age on male fertility variables in the mouse. Experimental males were fed a standard diet supplemented with either a low or high dose of vitamins C and E. Oocytes enclosed in cumulus masses were inseminated using a 2 x 2 factorial design established according to whether males were young (3-4 months of age) or aged (22-24 months of age) and whether they were fed a control or antioxidant diet. Aged males showed a significant decrease in number of spermatozoa/mg epididymis when compared to young males. Dietary supplementation with low doses of vitamin…
Antioxidant therapy counteracts the disturbing effects of diamide and maternal ageing on meiotic division and chromosomal segregation in mouse oocytes
This study aims (i) to ascertain whether oxidative-stress-induced disturbances in chromosomal distribution in the metaphase-II spindle of mouse oocytes can be counteracted by supplementing culture medium with antioxidants; and (ii) to determine whether supplemental intake of antioxidants neutralizes the disturbing effects of maternal ageing on segregation of chromosomes during the first meiotic division and distribution of chromosomes in the metaphase-II spindle. (i): Germinal vesicle oocytes from unstimulated 10-12 week old mice were matured in vitro in the presence or absence of diamide and/or dithiothreitol. Metaphase-II oocytes were fixed and stained with 4',6-diamidino-2-phenylindole (…
The oxidizing agent tertiary butyl hydroperoxide induces disturbances in spindle organization, c-meiosis, and aneuploidy in mouse oocytes
It has been recently proposed that a concomitant generation of oxidative stress of oocytes with increasing maternal age may be a major factor responsible for the age-related increase in aneuploid conceptions. As a preliminary step in the testing of this hypothesis, we need to confirm that oxidative stress in itself can induce errors in chromosome segregation. In order to achieve this goal, germinal vesicle (GV)-stage mouse oocytes from unstimulated ICR and (C57BL x CBA) F1 hybrid female mice were matured in vitro for 9 h for metaphase I (MI) oocytes or 16 h for metaphase II (MII) oocytes in the presence of varying concentrations of the oxidizing agent tertiary-butyl hydroperoxide (tBH). MII…
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro.
The present study was designed to ascertain whether the negative effects on reproductive potential of post-ovulatory ageing in vitro of oocytes can be prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were aged in vitro for 12 h prior to insemination in the presence of varying concentrations of L-ascorbic acid, 6-methoxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was associated with lower fertilization rate, higher proportion of concepti exhibiting cellular fragmentation at 24 h post-insemination and lower percentage of…
Effects of maternal ageing and dietary antioxidant supplementation on ovulation, fertilisation and embryo development in vitro in the mouse.
The present study aims to ascertain whether dietary supplementation with a mixture of vitamins C and E may prevent the maternal-age-associated decrease in both the number of ovulated oocytes after exogenous ovarian stimulation and embryo development in vitro in the mouse. Experimental females were fed a standard diet supplemented with i) high doses of vitamins C and E from the first day of weaning until 12 or 40 weeks of age; or ii) moderate doses of vitamins C and E from the first day of weaning until 12 weeks of age or from 22 to 33 weeks of age. The age-related reduction in ovulation rate was partially prevented by supplementing diet with high doses of vitamins C and E from the first day…