Immunocytological localization of LH, FSH, TSH and their subunits in the pituitary of normal and anencephalic human fetuses

Abstract

Immunostaining with antisera to oLH, hCG, hLH, pLHbeta, hFSH, hFSHbeta, hTSHalpha and bTSH was used to delineate the gonadotropic and thyrotropic cells of the human fetal anterior pituitary. Hypophyses from 29 normal fetuses, 3 newborn infants, and 5 totally ancencephalic fetuses were used. Several controls to check for the specificty of the immunocytological reaction were made. In normal fetuses, observations showed that: 1) the alpha subunit was detected from the eighth week and throughout gestation without sex differences; 2) intact LH was detected during the third month, however, age and sex differences were observed during the fourth and fifth months; 3) intact FSH was detected in female fetuses from the beginning of the fourth month, a sex difference was observed; 4) LH and FSH were detected in the same cells; 5) the thyrotropic cells were detectable from 15 weeks of gestation and their number increased during gestation without sex difference; 6) at birth the gonadotropic cells were scarce and were located in the ventromedian zone of the anterior pituitary, while the thyrotopic cells remained numerous and were located in the dorsomedian zone. In amencephalic fetuses: 1) the alpha subunit existed at each stage studies; 2) the reaction induced by anti-pLHbeta and anti-hFSHbeta sera was alwys very weak regardless of sex or age; 3) the thyrotropic cells were more numerous in comparison to the gonadotropic cells. These data are discussed in terms of the relationship of the hypophysiotropic hypothalamic factors to the appearance and evolution of the glycoprotein hormones and their subunits.

Human Fetal Adenohypophysis

“…There is evi dence that pituitary production of free «-subunit decreases as production of TSH, FSH, and LH matures and the fetal hormone: «-subunit ratio approaches that of the adult [28]. Our findings confirm the maturation of «-subunit-contain ing cells as did the immunohistologic studies of other inves tigators [10,20,21]. It appears, therefore, that there is, dur ing fetal development, an «-subunit cell which may repre sent the precursor of the glycoprotein cell line and possibly the cell of origin of «-subunit-secreting adenomas [2], Thyrotrophin.…”

Topographical appearance of adenohypophysial cells with special reference to the development of the portal system.

“…Immunohistochemical studies on the chronological cytogenesis of the adenohypophysis have been made in rats (SETALO andNAKANE, 1972, 1976;SETALO et al, 1976;TOUGARD et al, 1977;CHATELAIN et al, 1979;WATANABE and DAIKOKU, 1979), in mice (GROSS and BAKER, 1979) and in human fetuses (BAKER and JAFFE, 1975;BUGNON et al, 1977;DUBOIS et al, 1978). However, very little attention has been payed on the topographical distribution of the differentiating cells (BAKER and JAFFE, 1975;DUBOIS et al, 1978;GROSS and BAKER, 1979).…”

“…Immunohistochemical studies on the chronological cytogenesis of the adenohypophysis have been made in rats (SETALO andNAKANE, 1972, 1976;SETALO et al, 1976;TOUGARD et al, 1977;CHATELAIN et al, 1979;WATANABE and DAIKOKU, 1979), in mice (GROSS and BAKER, 1979) and in human fetuses (BAKER and JAFFE, 1975;BUGNON et al, 1977;DUBOIS et al, 1978). However, very little attention has been payed on the topographical distribution of the differentiating cells (BAKER and JAFFE, 1975;DUBOIS et al, 1978;GROSS and BAKER, 1979). In rats it has been shown that ACTH cells were first found in the ventro-medial portion of the pituitary on day 15.5 of gestation, TSH cells appeared in the posterior half of the pituitary on day 16.5, and LH cells were revealed one day later in a narrow ventral area in the anteromedial portion of the pituitary (WATANABE and DAIKOKU, 1979 Roles of the developing hypothalamus and the portal vessels.…”

Immunocytological study of the chronology of pituitary cytogenesis in the domestic pig (Sus scrofa) with special reference to the functioning of the hypothalamo-pituitary-gonadal axis

“…Dubois, 1969 ;Dacheux and Dubois, 1976 ; pigs : Dacheux, 1978Dacheux, , 1981 ; sheep : Dubois and Mauleon, 1969 ; primates : Girod and Dubois, 1976 ;humans : Begeot et al, 1978 ;Dubois et al, 1978) and the hypothalamus Dubois and Barry ;1974 ;Paulin et al, 1977 ;Tramu et al, 1977 ;review in Barry, 1979 In figure 1 showing a 50-day fetus, the situation was somewhat different.…”