[Histochemical and histological investigations on the vagina of the beagle she-dog during various functional conditions (author's transl)]

Abstract

Histotopochemistry and histology of vaginal epithelium in female beagles were studied during oestrus, metoestrus-dioestrus, post partum period and at days 20, 30, 40, 50, 60 of pregnancy. During oestrus the epithelium is uniform throughout the whole vagina: it presents itself as a high, uncornified, stratified squamous epithelium with some glycogen and lipid droplets but devoid of leucocytes. The intercellular gaps of the stratum intermedium give strong reactions for ATPase and alkaline phosphatase. The activities of oxidoreductases studied decrease continuously from basal to apical. During gravidity, post partum period and metoestrus-dioestrus distinct morphological and histochemical differences can be stated between the cranial and caudal vaginal portions. Caudal vaginal epithelium outside oestrus remains of stratified squamous type. It exhibits strong mucification during pregnancy. The PAS-positive mucous substances prefer a position in the enlarged intercellular gaps of stratum intermedium and superficiale. During pregnancy the epithelium is relatively rich in acid and completely devoid of alkaline phosphatases. Outside oestrus the epithelium of the cranial vaginal region is a relatively flat, stratified columnar one and contains leucocytes with regularity. Also the cranial vaginal portion undergoes mucification during pregnancy with a maximum about day 33. The mucous material is situated intracellularly and not within the intercellular gaps. Further, larger intraepithelial mucus cysts are observed. Alkaline phosphatase is found during gravidity in the basal region and an adluminal border of the epithelium. The reactions for oxidoreductases are strongest in the columnar cell layer which shows more functional adaptations than the remainder of the epithelium. Histochemical tests for beta-D-glucuronidase and leucine aminopeptidase give negative results in the whole vagina during all different functional stages studied.