Search results for "Spermatogenesis"

Dietary antioxidant supplementation did not affect declining sperm function with age in the mouse but did increase head abnormalities and reduced spe…

1998

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…

Anti-aging activity of the Ink4/Arf locus.

2009

The proteins encoded by the Ink4/Arf locus, p16Ink4a, p19Arf and p15Ink4b are major tumour suppressors that oppose aberrant mitogenic signals. The expression levels of the locus are progressively increased during aging and genome-wide association studies have linked the locus to a number of aging-associated diseases and frailty in humans. However, direct measurement of the global impact of the Ink4/Arf locus on organismal aging and longevity was lacking. In this work, we have examined the fertility, cancer susceptibility, aging and longevity of mice genetically modified to carry one (Ink4/Arf-tg) or two (Ink4/Arf-tg/tg) intact additional copies of the locus. First, increased gene dosage of …

A comparison of the effects of bilateral efferent duct ligation and of partial epididymectomy on the testes of rats.

1990

Testis weight as a percentage of body weight did not change following bilateral ligation of the efferent ducts (EDL) close to the epididymis, whereas following removal of part of the epididymis between the site of ligation and a point close to the junction between the caput and corpus (PCE), testis weight first rose linearly until Day 4 and then showed an exponential decrease between Days 4 and 28. After EDL, the perimeter of the seminiferous tubules rose for the first 7 days and then remained elevated, whereas after PCE, there was a linear decrease between Days 4 and 28. Following EDL, the percentage of altered and degenerated tubular cross-sections rose to about 30% and 10%, respectively,…

Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.

1991

Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.

In vivo studies on the antiandrogenic effects of cimetidine versus cyproterone acetate in rats

1981

To investigate the antiandrogenic action of cimetidine in vivo, prostatic androgen uptake and metabolism, spermatogenesis, morphology of the prostate and testes, and plasma hormone levels were studied using Sprague-Dawley rats, and the results were compared with the effects of cyproterone acetate or castration. Cimetidine and cyproterone acetate caused significant reduction in the weights of the ventral prostate and testes. The changes of ventral prostate were accompanied by a dose-related epithelial atrophy. No adverse effect on spermatogenesis was observed after treatment with cimetidine at daily doses of 50 mg/kg or cyproterone acetate of 10 mg/kg. Although cimetidine treatment induced a…

Abnormalities caused by chloroform and ether in the spermatogenesis of mammals [Chloroforma un ētera radītie traucējumi zīdītāju spermatogenezē]

1937

Teksts angļu valodā, kopsavilkums latviešu valodā.

Two proteases from nuclei of rat testis cells. II. Inhibitors

1987

Abstract Proteases Rc and Kc of the nuclei of rat testis cells exhibit considerable differences in susceptibility to various protease inhibitors. Protease Rc is inhibited by D‐phenylalanyl‐L‐propyl‐L‐arginine chlormethylketone and p‐nitrophenyl‐p1‐guanidino ben‐zoate. Protease Kc is inhibited by Nα‐p‐tosyl‐L‐lysine chlormethylketone, N‐p‐tosyl‐phenylalanine chlormethylketone, N‐carbobenzoxy‐L‐phenylalanine chloromethylketone and p‐nitrophenyl‐p'‐guanidino‐benzoate. Neither protease is inhibited by 10 mM phenylmethanesulphonyl‐fluoride or p‐chloromercuri‐benzoate. p‐nitrophenyl‐p1‐guanidino‐benzoate is a substrate for protease Rc with release of p‐nitrophenol, however the protease activity i…

2002

Analysis of gonad organization and development revealed that Serranus atricauda is a functional simultaneous hermaphrodite. The ovary is classified as asynchronous. Oocyte growth is divided into five stages: stage I (primary growth stage), stage II (yolk vesicle formation), stage III (vitellogenesis), stage IV (oocyte maturation) and stage V (mature egg). The testis is of the unrestricted or lobular spermatogonial type. Spermatogenic cells include spermatogonia, primary and secondary spermatocytes, spermatids (which form cysts in the seminiferous tubules) and spermatozoa (free in the lumen). The histological structure of the gonad and sperm morphology would seem to indicate that this specie…

65 ASSOCIATION BETWEEN ALDOSTERONE AND CORTISOL LEVELS DURING THE OVULATORY PERIOD IN SPANISH PUREBRED MARES

2014

Preovulatory increased aldosterone (ALD) has been described as one of the physiological events that characterise the oestrous cycle in relation to the dynamics of the renin angiotensin aldosterone system. Within the mechanisms associated with this response are the stimulating effect of oestrogen on the synthesis of angiotensinogen, haemodynamic variations of renal blood flow, changes in sodium concentration, changes in the local sympathetic activity, and the effect of cortisol (CORT). In fact, CORT via adrenocorticotropic hormone contributes primarily to preovulatory ALD, and it is the primary regulator factor synthesis ALD (Chidambaram et al. 2002; Pechère-Bertschi et al. 2002; Szmuilowic…

Antioxidants in ICSI

2013

Male factor infertility can be caused by reasons, either related or not with total sperm production. Among causes of male infertility in cases of normal sperm count and motility, oxidative stress is one of the most relevant processes influencing fertility in vivo or in assisted reproduction treatments’ results. This chapter provides the most updated information regarding the oxidative stress situation in sperm and the relevance of antioxidants use in intracytoplasmic sperm injection results.