Analysis of age-associated changes in mitochondrial free radical generation by rat testis

Abstract

Throughout spermatogenesis, mitochondria undergo a morphological and functional differentiation. Mitochondria are involved in the production of reactive oxygen species (ROS), considered one of the mediators of ageing. Particularly, lipid peroxidation is regarded as a major phenomenon by which ROS can impair cellular function. In the present study, we examined the production of superoxide anion, superoxide dismutase activity and the effect of Fe(2+)/ascorbate induced-lipid peroxidation on the respiratory chain activities of testis mitochondria throughout the process of spermatogenesis and ageing. Mitochondria from rat testes generated superoxide anion, mainly using NADH as substrate, which increased according to age. The activity of SOD is age-dependent and greatly stimulated during the first wave of spermatogenesis, but decreases in adulthood and old age. TBARS concentration was also markedly increased by ageing. The activity of mitochondrial respiratory chain complexes is differentially affected by oxidative stress induced by iron/ascorbate, succinate-dehydrogenase activity being less vulnerable than that of NADH-dehydrogenase and cytochrome c oxidase. The data suggest that ageing is accompanied by reduced activity of SOD, leading to excessive oxidative stress and enhanced lipid peroxidation that compromises the functionality of the electron transport chain. The data support the concept that mitochondrial function is an important determinant in ageing.

Changes in mitochondrial energy utilization in young and old worker honeybees (Apis mellifera)

“…These observations are consistent with previous reports that ATP synthase activity decreases with advancing age in the erythrocytes of cows (Bartosz et al 1982) and the hearts of mice (Yarian et al 2005). Similarly, NADH dehydrogenase activity has also been reported to decrease with advancing age in the kidneys, livers, and testes of rats (Napoleone et al 1991;Torres-Mendoza et al 1999;Vázquez-Memije et al 2008), as well as in the livers and brains of mice (Navarro et al 2002;Navarro 2004).…”

Accelerated aging of reproductive capacity in male rat offspring of protein-restricted mothers is associated with increased testicular and sperm oxidative stress

“…Vazquez-Memije et al, have reported that ROS generation and the capacity of the antioxidant system are significantly increased and decreased, respectively, in adulthood and older ages in animals on a control diet (Vazquez-Memije et al 2008). In contrast with the rat, we observed a fall in both SOD and GPx in early life in the C group.…”

Effects of parsley supplementation on the seminal quality, blood lipid profile and oxidant status of young and old male rabbits

“…Our results indicated that inclusion of parsley in the diet caused an increase in the total antioxidant capacity, and these outcomes were in line with the results reported by (Nielsen et al, 1999;Rajeshwari et al, 2011a,b;Dixit et al, 2005). Reactive oxygen species concentrations increase with age, concomitantly with decreases in antioxidant levels (Weir and Robaire 2007;Vazquez-Memije et al, 2008). Malondialdehyde is a major reactive aldehyde that appears during the peroxidation of biological membrane polyunsaturated fatty acid (Vaca et al, 1988).…”