AIMTo examine the effects on rat aging of caloric restriction (CR1) and undernutrition (CR2) on the body and on testicular weights, on two enzymatic antioxidants (superoxide dismutase and catalase), on lipid peroxidation and on the expression of testicular aromatase and estrogen receptors (ER).

METHODSCR was initiated in 1-month-old rats and carried on until the age of 18 months.

RESULTSIn control and CR2 rats an age-related decrease of the aromatase and of ER (alpha and beta) gene expression was observed; in parallel a diminution of testicular weights, and of the total number and motility of epididymal spermatozoa was recorded. In addition, aging in control and CR2 rats was accompanied by a significant decrease in testicular superoxide dismutase, catalase activities, and an increase in lipid peroxidation level (thiobarbituric acid reactive substance), associated with alterations of spermatogenesis. Conversely, caloric restriction-treatment exerted a protective effect and all the parameters were less affected by aging.

CONCLUSIONThese results indicate that during aging, a low caloric diet (not undernutrition) is beneficial for spermatogenesis and likely improves the protection of the cells via an increase of the cellular antioxidant defense system in which aromatase/ER could play a role.

Age Factors ; Aging ; metabolism ; physiology ; Animals ; Aromatase ; biosynthesis ; metabolism ; Caloric Restriction ; Catalase ; metabolism ; Down-Regulation ; Estrogen Receptor alpha ; biosynthesis ; metabolism ; Estrogen Receptor beta ; biosynthesis ; metabolism ; Gene Expression ; Humans ; Lipid Peroxidation ; Male ; Malnutrition ; metabolism ; Models, Animal ; Rats ; Rats, Wistar ; Superoxide Dismutase ; metabolism ; Testis ; metabolism ; physiology

AIMTo investigate the effects of 17beta-estradiol (E2), Peganum harmala extract (PHE) and caloric restriction (CR) on various testis parameters during aging.

METHODSTwelve month-old male rats were treated for 6 months with either E2 or PHE, or submitted to CR (40%).

RESULTSOur results show that estrogens and CR are able to protect the male gonad by preventing the decrease of testosterone and E2 levels as well as the decrease of aromatase and estrogen receptor gene expressions. Indeed, E2, PHE and CR treatments induced an increase in the superoxide dismutase activities and decreased the activity of testicular enzymes: gamma-glutamyl transferase, alkaline phosphatase, lactate deshydrogenase as well as the aspartate and lactate transaminases in aged animals. In addition, the testicular catalase and gluthatione peroxidase activities were enhanced in E2, PHE and CR-treated rats compared to untreated animals at 18 months of age. Moreover, the positive effects of estradiol, PHE and CR were further supported by a lower level of lipid peroxidation. Recovery of spermatogenesis was recorded in treated rats.

CONCLUSIONBesides a low caloric diet which is beneficial for spermatogenesis, a protective antioxydant role of estrogens is suggested. Estrogens delay testicular cell damage, which leads to functional senescence and, therefore, estrogens are helpful in protecting the reproductive functions from the adverse effects exerted by reactive oxygen species (ROS) produced in large quantities in the aged testis.

Aging ; physiology ; Animals ; Antioxidants ; metabolism ; Aromatase ; biosynthesis ; genetics ; Caloric Restriction ; Estradiol ; metabolism ; pharmacology ; Estrogens ; pharmacology ; Lipid Peroxidation ; drug effects ; Male ; Oxidative Stress ; drug effects ; Peganum ; chemistry ; Plant Extracts ; pharmacology ; RNA ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Receptors, Estrogen ; biosynthesis ; genetics ; Testis ; drug effects ; enzymology ; growth & development ; Testosterone ; metabolism ; Thiobarbituric Acid Reactive Substances ; metabolism