Connective tissue aging in the human hypophysis-gonadal system.

The basic issue in our project was to quantify the age-process in the human hypophysis-gonadal system. Of the many aspects of aging, we estimated, using human autopsy material, the content of desoxyribonucleic acid (DNA), of hydroxyproline, of hexosamines and of uronic acids in the hypophysis, testis, and ovary. The respective organs were weighed and homogenised in acid-buffer solution after which, for each of the parameters, 1.0 ml of homogenate was extracted and processed: DNA-estimation according to modified Dische/Seibert (1929) method; hydroxy-proline according to Stegemann and Stalder (1967); hexosamines and uronic acids according to Gatt and Berman (1966) and Blumenkrantz and Asboe-Hansen (1973) respectively. All values obtained were expressed in micrograms/ml of homogenate. The age investigated ranged from a few days old to 99 years. The DNA-curves for the hypophysis initially showed a decline till about the third decade of life and then remained almost constant with a significant decline up to the senile age. The DNA-curves for the testis and ovary demonstrated a sharp decline initially till the third decade of life, after which the curves remained constant, but showed reduction during higher age. Similar pattern of distribution was also observed for hexosamines, and uronic acids: after the initial decline of uronic acids in the human hypophysis and testis during the first three decades of life and nearly constant values thereafter, hexosamines, together with the uronic acids show minimal decrease in content during the senile period. Contents od hydroxyproline significantly increased in testis, ovary and hypophysis with aging. This biochemically proven age-fibrosis in the human gonads corresponds to the morphologically observed vascular and interstitial sclerosis in the testis and the ovary and may partly help to explain the declined sensitivity of these target organs to hypophyseal stimulation during the aging period.