The impairment of metrial gland development in tamoxifen exposed rats.

We examined the sequential histopathological changes in the placenta from rats exposed to tamoxifen. Tamoxifen was administered intraperitoneally at doses of 0 and 2 mg/kg/day on gestation days (GDs) 8, 9 and 10, and the placentas were sampled on GDs 11, 13, 15, 17, and 21. The fetal mortality rates in the tamoxifen group were increased up to 56%. However, there were no effects on the weights of live embryos/fetuses and their placentas. Histopathologically, the size of metrial gland in the tamoxifen group was reduced on all sampling times. The spiral arteries appeared less well developed in the hypoplastic metrial gland. A decrease in uterine natural killer (uNK) cells and mitotic uNK cells around the spiral arteries in the metrial gland was detected from GD 13 onward and on GDs 11 and 13, respectively. There were no obvious changes in the labyrinth zone or basal zone. We consider that the anti-estrogen effect of tamoxifen inhibits the proliferation of decidualized endometrial stromal cells in the metrial gland and leads to inhibition of the proliferative activity of uNK cells, followed by defective development of spiral arteries, and metrial gland hypoplasia. It is assumed that the metrial gland hypoplasia might be involved in the tamoxifen-induced embryo/fetus-toxicity.

Experimentally induced mastitis and metritis modulate soy bean derived isoflavone biotransformation in diary cows.

The present study compared the changes in isoflavone (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cows with induced mastitis and metritis after feeding with soy bean. Sixteen cows were divided into four groups: control for mastitis group, cows with induced mastitis group, control for metritis group, and cows with induced metritis group. All cows were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on HPLC system. ß-Glucuronidase activity in the blood plasma of cows was measured by fluorometric method. In the blood plasma of cows with induced mastitis and metritis, we found considerably higher concentrations and time-dependent increase in isoflavone metabolites (equol and para-ethyl-phenol) with reference to cyclic cows (P < 0.05). Moreover, we noticed significant decrease of genistein in the blood plasma of the cows with induced metritis compared with control cows (P < 0.05). In addition, in the blood plasma of the cows with induced metritis, we found an increase in ß-glucuronidase activity compared with control cows (P < 0.05). In conclusion, health status of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the cows. Experimentally induced mastitis and metritis increased isoflavone absorption, biotransformation and metabolism. Therefore, we suggest that cows with induced mastitis and metritis are more exposed to active isoflavone metabolite actions than healthy cows.

Vascular endothelial growth factor production by rat granulated metrial gland cells and their morphological features in normal and pathological conditions.

Granulated metrial gland (GMG) cells are pregnancy-specific cells that may have many functions in successful placentation and pregnancy. In the present study, changes in the rat GMG cell structure, distribution and vascular endothelial growth factor (VEGF) expression during early pregnancy were evaluated by light microscopy. Implantation sites taken from females with spontaneous abortion were also investigated. On Day 7 of pregnancy, GMG cells were distributed through the implantation and interimplantation sites. They formed metrial glands in the mesometrial triangle on Day 9, and were observed in the decidua basalis on Day 14 of pregnancy. Avidin-biotin complex immunohistochemistry revealed that GMG cells showed moderate staining for VEGF at the beginning of pregnancy and intense staining on Days 9 and 10 of pregnancy. They were localised mostly near the newly formed blood vessels. The implantation sites from spontaneously aborting females showed numerous leucocytes in the lumen of mesometrial blood vessels. In spontaneously aborting females, GMG cells showed a distinct morphology, increased in number and volume, their granules were denser and degranulation was observed. These results suggest that rat GMG cells might be a guide for placental angiogenesis and they might share a role with leucocytes in pathological conditions.

Histological study of granulated metrial gland (GMG) cells in beige (DA-bg/bg) rats.

To clarify the roles of granulated metrial gland (GMG) cells for successful pregnancy in rats, GMG cells in beige rats (genotype: DA-bg/bg), whose NK cells show lysosomal dysfunction because of abnormalities in cytoplasmic granules, were examined in mid- and late-pregnancy by light and electron microscopies. The GMG cells of beige rats were significantly less in number than those of the two controls (genotypes: DA-bg/+ and DA-+/+) in mid- and late-pregnancy, and this accompanied a low reproductive performance in the beige rats. The size of intracellular granules in the GMG cells of the beige rats was larger than for the two controls on each corresponding day of pregnancy. These results suggest that the activity of rat GMG cells and peripheral NK cells might be influenced by the beige gene, which is involved in reproductive performance.

[Pathology of placenta of rats induced by fatty acid deficiency]. / Patología de la placenta de rata inducida por la deficiencia de ácidos grasos.

Lipids are important cell components, both from the structural and the functional point of view. Besides, they intervene in transporting functions, cell recognition and immunity. Essential Fatty Acids (EFA) are important for the functional and structural maintenance of animal organisms. In our laboratory, it was demonstrated that one group of pregnant rats fed on an EFA deficient diet, and other group of rats fed on the same diet but with 5% of corn oil (rich in linoleic acid) showed alterations on the development of the metrial gland. In the present work, 57 female rats of a Wistar strain were fed since weaning with one of the following diets: EFAD: deficient in essential fatty acids, COD: EFAD + 5% corn oil (linoleic acid sufficient but alpha-linoleic acid deficient); SAD: EFAD + 5% soy oil (both EFA sufficient) and CD: commercial diet. After 3 months the animals were sacrificed on the 13 th. day of gestation. Uteru's horns were dissected and the implantation sities were fixed on formol and embebbed in parafin. The observations were carried out with H/E coloured cross-sections and the corialantoidea placenta, the cities of implantations and the sitios of reabsortions were studied. The metrial gland of DAGE and DAM rats presented structural modifications compared to DC rats. The most relevant findings were: indifferentiation of the granulated metrial gland cells and an increase in the amount of connective tissue. In DAS rats, on the contrary, the aspect of the metrial gland was similar to the observed in the DC group. In the DAGE and the DAM groups Labyrinthium was enlarged with vascular septum group. Mean while DAS was similar to group DC (thin and vascular). Differences in the cities of implantations and reabsortions were not detected. The present results suggest that alpha-linolenico acid is essential for the rat placenta to reach normal development.

Experimental evidence of secretion by mouse granulated metrial gland cells.

Granulated metrial gland cells are cytotoxic cells found in the uterine wall in pregnancy. In this study, the involvement of the cytoplasmic granules of mouse granulated metrial gland cells during cytolysis of fibrosarcoma Wehi 164 cells was investigated in vitro. Using the lectin Helix pomatia agglutinin which binds to the granule membrane, but not to the cell membrane, of mouse granulated metrial gland cells, the limiting membrane of one or more cytoplasmic granules became incorporated into the cell membrane of the granulated metrial gland cells during cytolysis of Wehi 164 cells. It is concluded that this occurs during exocytosis of the contents of the granules and describes the first experimental evidence of secretion by mouse granulated metrial gland cells.

Appearance of eosinophilic granule cells as pathological changes in the uteri of two aged virgin Donryu rats.

The morphological features of cells containing eosinophilic granules (EG cells) present as pathological changes in the uteri of 2 aged virgin Donryu rats were described and compared with granulated metrial gland (GMG) cells of a pregnant rat. Microscopically, EG cells distributed diffusely from the mesometrial triangle to the subendometrium with partly focal accumulation in Case 1 and infiltrated diffusely from the endometrium to the serosa without any clumping in Case 2. They were large cells with eosinophilic and hyaline intracytoplasmic granules, positive for the periodic acid-Schiff reaction. Both EG and GMG cells reacted positively to concanavalin A, wheat germ agglutinin, and phytohemagglutinin on lectin histochemical investigation, although common results were not always obtained for immunohistochemistry. These results show that EG cells are morphologically similar to GMG cells, suggesting a possibility that EG cells are GMG cells. EG cells were without neoplastic properties or pronounced cell-proliferative activity. In Case 1, histological changes of the ovaries and vagina were indicative of a pseudopregnant status. In Case 2, the rat had been maintained under abnormal hormonal conditions, and no evidence of any pseudopregnant-like status was found. These results suggest, thus, that the appearance of EG cells is evidence of a reactive pathological condition in the uteri of aged virgin rats, although the precise pathogenesis and biological significance of EG cells remain to be determined.

A study of granulated metrial gland cells in the pregnant, alymphoplasia (aly/aly) mice.

During pregnancy, a population of uterine NK cells, commonly called granulated metrial gland (GMG) cells, differentiates in the uterus of both immune competent and various immunodeficient mice. Regulatory mechanisms controlling the differentiation of GMG cells are not fully known. It has been proven that GMG cells are derived from bone marrow, appear under the influences of progesterone and estrogen, do not require the presence of an embryo, and are associated in rodents with decidualization of the uterine stroma. Mice of genotype aly/aly are genetically deficient in lymph nodes and Peyer's patches due to a lymphoid-associated mesenchymal disorder. They are considered to be a useful model for the study of interactions between lymphocytes and stromal components. This immunodeficient animal is completely different from nu/nu and scid/scid mice who differentiate GMG cells during pregnancy. To determine whether the differentiation of GMG cells depends on mesenchymal interactions in the uterus, aly/aly mice were studied histologically between days 10 and 14 of pregnancy for differentiation of GMG cells and development of the metrial gland. Metrial gland tissue was present and appeared normal in aly/aly mice. There were no significant differences in the distribution of GMG cells in comparison to control pregnant aly/+ mice. Fewer GMG cells were present in aly/aly mice than aly/+ mice on days 12 and 14 of pregnancy. The features of individual GMG cells were different on days 10 and 12 of pregnancy. GMG cells in aly/aly mice were small in size and the granules were poorly developed. By day 14, however, GMG cells acquired a mature size and the granules appeared mature. It is likely that GMG cell differentiation was delayed in pregnant aly/aly mice, due to a mesenchymal disorder affecting metrial gland development in this animal.

Perforin-expressing cells during spontaneous abortion.

The metrial gland of pregnant rodents contains an abundant population of natural killer (NK)-like cells called granulated metrial gland (GMG) cells. Since GMG cells express the cytolytic protein, perforin, and since cells with NK activity have been implicated in spontaneous abortions, we have studied the distribution of perforin-containing cells in the uterus of mice undergoing normal pregnancy (Swiss mice) and spontaneous abortions (CBA/J x DBA/2 mice). The distribution of perforin-positive GMG cells was essentially the same near healthy and aborting conceptuses, suggesting that GMG cells are not involved in most cases of spontaneous abortion in this abortion model. Small perforin-positive cells were observed near the aborting conceptus in about 5% of the cases. However, it is not known whether their presence was the result or the cause of abortion.

Granulated metrial gland cells in the lungs of mice in pregnancy and pseudopregnancy.

A study has been made, using light microscopy, of GMG cells in the lungs of pregnant mice and pseudopregnant mice with deciduomata. GMG cells are found in the lungs from Day 8 to Day 17 of pregnancy and are mainly located in the interalveolar septa. The temporal relationship between GMG cells in the lungs and GMG cells in the blood vessels of the decidua basalis and metrial gland suggests that the GMG cells in the lungs are migrants from the uterus. The presence of GMG cells in the lungs is considered in relation to the possibility that a site of functional importance to this cell type is the labyrinthine placenta. GMG cells are found in the uterine blood vessels and lungs of pseudopregnant mice with deciduomata. This finding suggests that the migration of GMG cells is under the influence of the mother rather than under the control of factors derived from the fetal allograft.

Changes in the metrial gland of the rat uterus following ovariectomy on day 10 of pregnancy.

Rats were subjected to ovariectomy or a control operation on day 10 of pregnancy and light and electron microscope studies carried out to examine the cells of the decidua basalis and the mesometrial triangle. Degeneration of the decidua basalis was rapid but proliferation in the mesometrial triangle and differentiation of the typical granulated cells continued for some time, and resulted in the formation of a metrial gland. The earliest effect noted in the metrial gland was the appearance of inclusions in the fibroblast-like stromal cells one day after ovariectomy. During the next four days many stromal cells became packed with a variety of inclusions and it is suggested that some of these may represent phagocytosed cellular debris. Some debris appeared to be in intercellular spaces and was probably derived from granulated cells. Some granulated cells appeared to develop apparently empty vacuoles and this may be a preliminary stage in degeneration. Although granulated cells decreased to become very few in number five days after ovariectomy, the precise mechanism of their loss and the relationship of this to the hormonal environment could not be established.