THE DEVELOPMENT OF A MATERNAL PREGNANCY REACTION IN THE FERRET

Abstract

Summary. A segment of the uterus in seven ferrets was isolated surgically before mating. The endometrium of this segment was traumatized at laparotomy 12 days after mating. Histological and electron microscopic examination of the traumatized endometrium 8 days later showed the development of a maternal pregnancy reaction. This was identical to the endometrial response resulting from the presence of normal trophoblast at an implantation site. It consisted of the formation and subsequent necrosis of symplasmal nests of endometrial epithelium and hypertrophy of the cells lining the endometrial capillaries. The capillary cells were cubical or columnar in shape and had a well-developed rough endoplasmic reticulum and Golgi apparatus, suggesting a secretory function. The cells appeared to produce a thick acid mucopolysaccharide membrane which might normally play a part in embryonic nutrition. Traumatization of similarly isolated segments of the uterus in ferrets during oestrus and anoestrus resulted in no specific response.