Influence of age on sperm production and testicular weights in men

Abstract

Age-related changes in daily sperm production (DSP) and testicular weights were investigated in paired testes from 89 men aged 21-50 years and 43 men aged 51-80 years. For both DSP/testis and DSP/g parenchyma, remarkably large standard deviations exceeded 50% of mean values. However, DSP/g and DSP/testis for both right and left testes were approximately 30% higher in the younger than in the older group (P less than 0.01) and were negatively correlated with age (P less than 0.01) when data from both groups were pooled. Weights of whole testes and of testicular parenchyma were similar in both age groups and were not significantly correlated with age. However, testicular tunic weights were 29% higher in the older group (P less than 0.001) and were positively correlated with age (P less than 0.001). Both testicular tunic weight and the % of total testis occupied by tunic were negatively correlated with DSP/g (P less than 0.01); these correlations were weakened by removing the effect of age. Although total testicular weight and testicular parenchymal weight did not change with age, these values were about 10% lower on the left than on the right (P less than 0.001). In addition to its increase with age, testicular tunic weight was about 8% greater for right than for left testes in all men (P less than 0.001). Although the average size of the testis varied from right to left, DSP/g was similar in paired testes (P = 0.15), and the correlation between right and left DSP/g was high (rho = +0.89, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Spatially dynamic expression of Sry in mouse genital ridges

“…This is significant in view of asymmetry in the distribution of testicular tissue in mouse hermaphrodites Washburn and Eicher, 1983), and documented cases of asymmetry between the left and right gonads in humans and chickens (Mittwoch, 1976(Mittwoch, , 1998(Mittwoch, , 2000Mittwoch and Mahadevaiah, 1980;van Niekerk and Retief, 1981;Johnson et al, 1984;Krob et al, 1994). We conclude that differences in expression between the left and Fig.…”

Effects of aging on the male reproductive system

“…Daily sperm production, total sperm count, and sperm viability are negatively correlated with age. Daily sperm production decreases more than 30 % in men over the age of 50 and is negatively correlated with age in men in general [13,20,21]. In a study where semen values of men above 45 years of age were analyzed, four measured parameters (semen volume, sperm concentration, sperm motility, and sperm morphology) and one derived parameter (total sperm count) were calculated according to the age range, and these values were compared to the reference values of the World Health Organization.…”

Male Infertility; Evidences, Risk Factors, Causes, Diagnosis and Management in Human

“…Advancing paternal age, occupation has been implicated in a broad range of abnormal reproductive and genetic outcomes. Lifestyle factors, including age when starting a family, nutrition, weight management, exercise, psychological stress, cigarette smoking, recreational and prescription drugs use, alcohol and caffeine consumption, may impact fertility [100].…”