Further Study of Factors Affecting the Metabolic Clearance Rate of Testosterone in Man1

ABSTRACT A study of the effect of various factors on the metabolic clearance rate of testosterone (MCRT) is presented. Change from the supine to the erect position resulted in a sharp fall in the MCRT in one subject, with little or no significant change in 3 additional subjects. In one of the latter group, however, there subsequently occurred a significant increase in the MCRT upon changing from the erect to the supine position. Acute increases in the plasma concentration of testosterone in normal menstruating women and in a bilaterally adrenalectomized castrated woman were not associated with any appreciable change in the MCRT until a plasma level of testosterone exceeding 1.2 μg/100 ml was reached. In a normal and a hypogonadal male, an acute increase in the circulating level of testosterone produced a moderate increase in the MCRT. The increase, however, was considerably smaller than that found after chronic administration of the steroid. The decrease in the plasma concentration of testosterone followi...