Effect of Age upon Uterine Response to Deciduagenic Stimulus

Abstract

The effect of aging upon ability of the uterus to respond to a deciduagenic stimulus was studied by transmission electron microscopy. Particularly, subtle structural characteristics of decidualization were sought in stromal cells of uteri of aged rats. To negate effects of ovarian aging, rats 4, 10 and 20–24 months of age were subjected to bilateral ovariectomy and subsequent ovarian hormone injections. As deciduagenic stimulus, sesame oil was injected into the right uterus. The left served as the hormone primed control; and only antimesometrial endometrium was examined. Oil-injected uteri of 4- and 10-month-old rats developed deciduomata which histologically were similar to published descriptions. No decidual changes were observed in the aged oil-injected uterus. Therefore, the experimental and control uteri appeared similar. Luminal epithelial cells of aged rats differed from those of younger animals primarily in possessing more lysosomes and fewer surface microvilli. Stromal cells of aged rats differed more in shape and in quantity of cytoplasm, and in these cells lipofuscin deposits were identified more frequently. Moreover, leukocytes, plasma cells and macrophages were more numerous in the aged uteri. Failure of the aged uterus to decidualize could not be correlated with any morphologic changes. Results are correlated with previously proposed explanations for failure of aged uteri to decidualize and, accordingly, to maintain implanting embryos.

Determinants of uterine aging: lessons from rodent models

“…First, the orientation of lumen was not usually as well organized as in the young animals; second, there was little evidence of corrugation in the epithelial surfaces [65], which further proved that the lumen is open in old mice fixed by the glutaraldehyde fixation. The same situation was noted in the old rat [66]. In senescing golden hamsters, both closure and implantation were deferred by approximately 12 h and luminal closure was found only around the implanting embryos [67].…”

“…The stroma cells, which need to be differentiated to decidual cells, also had different appearances between the young and old animals. There was an increase in lipofuscin deposits in the cytoplasm of some aged stromal cells as well as an increase in the amount of collagen and in the number of lymphocytes, plasma cells, and macrophages [66]. The collagen was the most obvious difference.…”

Altered Surface Ultrastructure of the Uterine Epithelium in Aged Hamsters.

“…Appearance of short microvilli and apical cellular protrusions, noted in both young and aged hamsters, has been also observed in mice and rats [11][12][13][14][15]18] and believed to result from the direct influence of progesterone [11]. In the present study, apical cellular protrusions were sparse in the aged uterus and some of them were frequently detached.…”

“…These features resembled those observed in the mice and rats during early pregnancy [11][12][13][14][15]18]. It has been speculated that the changes in the microvilli and secretory activity may influence the transport of substances across the uterine epithelial membrane for contributing to the embryonic development [18].…”

“…Understanding the ultrastructural changes in the aged uterus may help explain the uterine contribution to the reduced fertility in the aged females. Numerous studies on the ultrastructural changes of the uterus have been conducted in the aged mice and rats [11][12][13][14][15], but little information on those in the aged hamsters is available [5]. In this study, therefore, the uterine luminal surface was examined by SEM to clarify ultrastructural characteristics related to the embryonic wastage in the aged hamsters before and during implantation.…”