Function of Corpus Luteum 



441 



221 (2181) 



The effect of extirpation of the uterus on the life and function of 

 the corpus luteum in the guinea pig. 



By LEO LOEB (by invitation). 



[From the Department of Comparative Pathology, Washington 

 University, St. Louis, Mo.] 



It is usually assumed that extirpation of the uterus is with- 

 out any noticeable effect on the ovaries, outside perhaps of 

 cystic degenerative changes which have sometimes been ob- 

 served to follow this operation and which evidently are due to 

 interference with the blood supply of the ovary following injury 

 of the uterine vessels. 



Experiments in the guinea pig have however convinced us 

 that a complete or almost complete extirpation of the uterus 

 may be followed by a very characteristic effect, namely a long 

 continued preservation and function of the corpus luteum. In- 

 stead of beginning to degenerate fourteen or fifteen days after 

 ovulation, the corpus luteum may remain well preserved and 

 even show attempts at mitotic proliferation for sixty days, or 

 perhaps even as late as eighty days after the last heat. We have 

 not yet determined the limit of preservation of the corpus luteum 

 under these conditions. The cyclic corpus luteum thus equals 

 or perhaps surpasses in vitality the corpus luteum of pregnancy 

 which latter has in the guinea pig a duration of about sixty- 

 five days. 



In order to demonstrate this effect we extirpated the uterus 

 a few days after ovulation. The corpus luteum which develops 

 as a result of ovulation remains preserved for a long time fol- 

 lowing this operation. If we extirpate the uterus in very young 

 guinea pigs at a time when an ovulation has not yet occurred, 

 the first ovulation takes place, notwithtanding the extirpation of 

 the uterus. In various experiments we observed this ovulation 

 to occur as early as nine days and as late as twenty-nine days 

 following the operation. The corpus luteum which thus orig- 

 inates remains then preserved for a long period of time and 

 mitotic figures may often be seen in the lutein cells. In ovaries 

 of these young animals, which ovulated for the first time fol- 



