Experimental Study of Ovarian Regeneration in Mice.

Abstract

Whether or not mammalian ovaries are capable of regeneration following complete ovariectomy seems still to be somewhat of a question. Davenport, 1 working on mice, found that, on the average, regeneration occurred in 64 per cent of his animals following removal of the ovaries. The experimental period ranged in time from 8 to 45 weeks, and he based his conclusions regarding ovarian regeneration upon the fact that post-mortem examination revealed distinct ovarian masses on the site of the original ovaries, and in many cases embryos were found in utero. No histological evidence was advanced, however, to show that all of the original ovary was removed in each case, and it seems essential that such evidence be established before it can be stated definitely whether regenerated ovarian tissue actually arises from the peritoneum, or from fragments of the original substance inadvertently left in situ.

Considering the importance of this subject in its bearing upon the problem of germ-cell origin, it has seemed desirable to repeat the experiment, basing any conclusions drawn upon histological study. Such evidence would show definitely two things: (1) whether or not all of the original ovary had been removed—a factor of prime importance—and (2) whether or not regenerated tissue actually is ovarian in nature.

Ninety-six operations were performed upon mice; 76 of the operated cases have been examined in connection with this report, having run over a period ranging from 7 to 16 weeks. Great care was exercised in removal of the ovaries, all of which were preserved for subsequent microscopic study to make certain that removal had been complete. The operative procedure was varied: in some cases the capsule was split and the ovary cut off at the hilus; in a majority of the operations, however, the capsule and hilus were included in removal; and in others a short section of the stalk was included as well.