[Testicular secretions of androgens after prolonged physical effort in man]

Variations in plasma testosterone, dihydrotestosterone. delta 4 androstenedione, LH, FSH and cortisol were measured before and after 6 succesive effort tests in 11 male subjects. Testicular secretion and the extra-hepatic consumption of androgens are increased by the haemodynamic conditions of effort but plasma levels of testosterone and dihydrotestosterone fall with repeated effort, indicating a progressive imbalance between production and consumption. These variations suggest that the testis, rather than glucocorticoid function of the adrenal, might play a major limiting role, psychological and metabolic, in tolerance of prolonged effort.

Ventricular compliance and ageing

Compliance of the right ventricle has been studied in 29 aged subjects who were free from any overt heart failure. The observations indicate that a loss of ventricular compliance results, in aged subjects, in an impairment of diastolic filling, which itself is responsible for a reduction in cardiac output. However, there appears to be no relationship between ventricular compliance and systolic performance but the failure to find any such relation may be due to a contractile adaptation in subjects having a low ventricular compliance.