BIOCHEMICAL EVIDENCE OF AGEING IN THE 

 PLACENTA 



Claude A. Villee 



Department of Biological Chemistry, Harvard Medical School, and Research 

 Laboratories, Boston Lying-in Hospital, Boston, Massachusetts 



The concept that the placenta undergoes regressive changes 

 in the latter months of gestation and that pregnancy is termi- 

 nated when the placenta can no longer provide an adequate 

 supply of nutrients to the child was originally stated by 

 Hippocrates (Reynolds, 1949). Careful histological and histo- 

 chemical observations (Wislocki and Bennett, 1943; Wislocki, 

 Dempsey and Fawcett, 1948) have provided evidence of 

 thickening and hyalinization of the walls of the blood vessels 

 and of the presence of thromboses in the last two or three 

 months of gestation. Decreases in the rates of oxygen con- 

 sumption and of anaerobic glycolysis as gestation proceeds 

 have been reported (Loeser, 1932; Wang and Hellman, 1941; 

 Page, 1948; Hellman, Harris and Andrews, 1950). The 

 present paper describes the results of investigations of the 

 intermediary metabolism of slices from placentas ranging in 

 age from six weeks to term. The metabolic activities of the 

 placenta decrease as gestation proceeds, but the decreases 

 are not general and uniform. The decreases in activity are 

 gradual, without sharp change near term, and the placenta 

 at term is still quite active in many respects. 



Term placentas were obtained directly from the delivery 

 room and were used within five minutes of delivery. Earlier 

 placentas were obtained at Caesarean sections performed for 

 delivery or for therapeutic interruption of pregnancy and 

 were used within five minutes of their removal from the 

 patient's body. Placental slices, about 0-5 mm. thick and 

 weighing about 200 mg., were cut with a Stadie-Riggs micro- 

 tome or with fine scissors. Care was taken in preparing the 

 slices to avoid areas of necrosis. The slices were incubated 



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