Summary
An ultrastructural study of gonadotropic pituitary cells was performed in estrogen-treated pregnant rats. Estradiol-treatment on Day 10 of pregnancy led to signs of ovulation or luteinization on Day 12 in 50% of the animals.
Degranulation was observed in the FSH and LH cells of estrogen-responsive rats, whereas in the unresponsive group, the same cells were intensely granulated. The FSH cells of the control group showed signs of degranulation which could be correlated with follicular development. LH cells were sometimes degranulated.
The role played by FSH and LH cells in the triggering of ovulation and luteinization by estrogen in the pregnant rat is discussed in the light of the ultrastructural observations.
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References
Aron, C., Asch, G., Roos, J.: Mise en évidence de l'action ovulatoire du rapprochement sexuel chez la ratte gestante. C.R. Soc. Biol. (Paris) 159, 2505–2508 (1965)
Costoff, A.: Ultrastructure of rat adenohypophysis -correlation with function, pp. 1–220. New-York-London: 1973
Everett, J.W.: Hormonal factors responsible for deposition of cholesterol in the corpus luteum of the rat. Endocrinology 41, 364–377 (1947)
Hassani, M., Roos, J., Roos, M.: Etude des cellules gonadotropes préhypophysaires dans les conditions de la ponte provoquée par l'oestradiol au cours de la gestation chez la ratte. C.R. Soc. Biol. (Paris) 168, 108–112 (1974)
Kurosumi, K.: Functional classification of cell types of the anterior pituitary gland accomplished by electron microscopy. Arch, histol. jap. 29, 329–362 (1968)
Long, J.A., Evans, H.M.: The oestrous cycle in the rat and its associated phenomena. Mem. Univ. Calif. 6, 1–148 (1922)
Mayor, H.D., Hampton, J.C., Rosario, B.: A simple method for removing the resin from epoxy embedded tissue. J. biophys. biochem. Cytol. 9, 909–910 (1961)
Morishige, W.K., Pepe, G.J., Rotschild, I.: Serum luteinizing hormone, prolactin and progesterone levels during pregnancy in the rat. Endocrinology 92, 1527–1530 (1973)
Purves, H.H., Griesbach, W.E.: The site of follicle stimulating and luteinizing hormone production in the rat pituitary. Endocrinology 55, 785–793 (1954)
Roos, J., Hassani, M., Roos, M.: Luteinizing and ovulatory action of oestradiol in the pregnant rat. Cell Tiss. Res. 161, 317–328 (1975)
Sawyer, C.H., Everett, J.W., Markee, J.E.: A neural factor in the mechanism by which estrogen induces the release of luteinizing hormone in the rat. Endocrinology 44, 218–233 (1949)
Schwartz, N.B., Talley, W.L.: Daily measurement of pituitary LH content during pregnancy in the rat: do cyclic changes persist? J. Reprod. Fertil. 15, 39–45 (1968)
Swezy, O., Evans, H.M.: Ovarian changes during pregnancy in the rat. Science 71, 46–50 (1930)
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This work was financed by the DGRST, contract no 74.7.0030
The authors wish to acknowledge the technical assistance of Mr. R. Dujol and Mr. F. Wolff
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Hassani, M., Roos, J. Ultrastructural changes of pituitary gonadotropic cells in estrogen-treated pregnant rats. Cell Tissue Res. 175, 73–84 (1976). https://doi.org/10.1007/BF00220824
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DOI: https://doi.org/10.1007/BF00220824