The endometrium is one of the most dynamic structures in the human body, characterized a complete life cycle ´within a short span -Qf time. During the ´past 50 ´years meticulotis, detailed descriptions have appeared of the cyclic morphologic charges of the human endometrium and their dependency on steroid. Although there can ba no doubt .about the role of estrogen in promoting endometrial growth and progesterone in influencing differentiation, little is known of the mechanisms by which such changes are accomplished. Investigators have reported observations on one to several enzyme system present in the endometrium.
If we are to achieve a better understanding of metabolic peculiarities of the endometrium, then a wider enzyme-profile should be investigated. The work reported here was carried out to investigate and describe various histochemical observations on: (j) normal rat´s endometrium, (n) the influence of sex steroids on ovariectomized rabbit endometrium, (IiJ) normal human endometrium.
Histochemical procedures: Periodic Acid Schiff (PAS) reaction for glycogen, alkaline phosphatase (ALP) and acid phosphatase (ACP) using Gomori´s method with fresh frozen -sections, DNA & RNA with Methylgreen Pyronin and Feulgen & Rossenbeck method.
( I) Normal rat´s endometrium
Cyclic variations of histochemical substances were observed in glandular epithelium and surface epithelium, in relation to the various stages of the estrous cycle.
(II) The influence of sex steroids on rabbit endometrium
(Histochemical observations in ovariectomized rabbit stimulated for 2 days with estr. ogen or progesterone)
:) Estrogen has the capacity to increase the amount of ALP activity and RNA. Because of the relationship of estrogen to both endometrial proliferation and ALP activity,it was suggested that the known effects of estrogen may be dependent on its ability to elicit
an increased response in ALP activity and that this may be a fundamental function of estrogen.
Progesterone, on the other hand, seems to augment the activity of ACP and glycogen, producing an environment suitable for the survival and implantation of the fertilized ovum.
(j1I) Normal human endometrium,
Thirty-nine hysterectomy specimens were obtained for histochemical procedures and semiquantitative estimates were graphically illustrated throughout the endometrial cycle.
Glycogen was present in abundant quantities during the entire secretory phase. ALP activity reached a peak during the late proliferative phase, especially in the luminal tips of the glandular epithelial cells and was present in decreasing amounts during secretory phase. ACP activity was low during the proliferative phase and was present in increasingly larger amounts as the progestational phase of the. cycle progressed. RNA is present in larger amounts during proliferation and conversely during the secretory phase.. DNA was relatively constant in nuclear distribution throughout the whole cycle.
In a general way the proliferative or "growth" €Shase of the endometrial cycle is characterized. histochemically by the presence *of large amounts of RNA and ALP activity, and small amounts of ACP activity and glycogen. Conversely, the progestational or "dif
ferentiated phase of the endometrial cycle is characterized by small amounts of RNA and ALP activity, and large amounts of ACP activity and glycogen.
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