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Search for other papers by Germana Grunert in
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Search for other papers by A. N. Tchernitchin in
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Different effects of oestrogen are mediated separately, by independent mechanisms of action. Accordingly, it has been shown that it is possible to dissociate these effects under various conditions which stimulate or inhibit responses selectively. The present study describes the action of progesterone on non-genomic responses to oestrogen stimulation which, it has been suggested, are mediated by eosinophils.
Oestrogen induced an increase in the number of eosinophils in the rat uterus, an increase in uterine wet weight and oedema of deep endometrial stroma (measured as decrease in cellular density). Progesterone induced a slight oedematous reaction in superficial endometrial stroma but did not induce uterine eosinophilia. Progesterone pretreatment of oestrogen-treated rats did not block oestrogen-induced uterine eosinophilia and oedema but induced an increase in the degranulation of uterine eosinophils. Therefore the number of eosinophils decreased without any change in the uterine oedema induced after 6 h of oestrogen action. The results corroborate previously published evidence of a dissociation of the action of oestrogen in independent groups of responses. Progesterone, a known blocker of some oestrogenic responses, did not block the effects mediated by eosinophils at 6 h after oestrogen administration; any change in these effects at later times can be explained by an earlier eosinophil degranulation under the action of progesterone.
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This work was aimed at testing whether oestrogen-induced changes in the uterus are responsible for uterine eosinophil migration or whether the effect is due to a direct action of oestrogen on the eosinophils themselves. Uterine eosinophil migration in response to intraluminal administration of oestradiol-17β into one uterine horn was measured in the injected and in the untreated contralateral horns. Uterine genomic responses (luminal epithelial and myometrial hypertrophy and nucleolar enlargement), known to depend on the local intra-uterine oestrogen level, were measured to control for the absence of hormone recirculation to the uninjected horn. The effects of intravenously administered oestradiol were also determined. Intraluminal injection of 0·1 ng oestradiol had no effect on either horn. With 10 ng, only the injected horn exhibited the genomic responses while eosinophilia developed to the same extent in both horns. With 100 ng, the genomic responses and eosinophilia were identical in injected and in contralateral horns. The results show that eosinophil migration depends on systemic levels of oestrogen, thus indicating that it is due to an oestrogen-induced change in a property of eosinophil leukocytes rather than a change in the uterus itself. As water imbibition showed the same pattern of responses as eosinophilia, this lends further support to the hypothesis of a role for eosinophils in oestrogen-induced uterine oedema.
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Search for other papers by A. N. Tchernitchin in
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ABSTRACT
The present study describes the effects of oestradiol-17β and diethylstilboestrol (DES) on several oestrogenic responses in the immature rat uterus Diethylstilboestrol was (1) weaker than oestradiol in inducing uterine eosinophilia, water imbibition and mitoses, (2) as strong as oestradiol in eliciting epithelial hypertrophy at 24 h after treatment, and (3) stronger than oestradiol in eliciting the reduction of epithelial cell height at 6 h after treatment and myometrial cell hypertrophy at 24 h after treatment. In addition, differences among the mitotic responses to oestrogen of the different uterine cell types were also detected. The above dissociation of the effects of DES and oestradiol-17β is in agreement with the hypothesis that eosinophil-mediated non-genomic responses, genomic responses and cell proliferation are mediated by independent mechanisms, involving different receptors which may have different affinities for both compounds. The eosinopenia and eosinophil degranulation under DES treatment suggest an explanation for the effect of DES on water imbibition. The dissociation among genomic responses from the different uterine cell types supports the hypothesis that different kinds of cytosol-nuclear oestrogen receptors exist.
J. Endocr. (1986) 110, 103–114
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Search for other papers by M. A. Mena in
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Search for other papers by A. N. Tchernitchin in
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ABSTRACT
Exposure of fetuses to some hormonally active agents may imprint permanent changes on the action of related hormones. These changes can be detected in adulthood as a modification of the degree of responsiveness to hormone action. The present study describes the effect of prenatal androgenization on the various responses to oestrogen in different types of cells in the uterus of prepubertal rats. Prenatal androgenization completely abolishes oestrogen-induced hypertrophy of uterine luminal and glandular epithelium, while it does not interfere with hypertrophy of circular myometrium and potentiates uterine eosinophilia and oedema. This dissociation between the various responses to oestrogen suggests that prenatal androgenization does not equally affect all uterine cell types.
Journal of Endocrinology (1989) 120, 379–384
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Search for other papers by M. A. Castrillón in
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Search for other papers by A. N. Tchernitchin in
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ABSTRACT
Oestrogen induces a migration of eosinophil leukocytes to the uterus where, it is suggested, these cells mediate several responses to hormone stimulation. To investigate the mechanism of the recognition of the uterus by the eosinophils, the present study describes the effect of a blockade of the rat reticulo-endothelial system with colloidal carbon on oestrogen-induced uterine eosinophilia, and other responses to oestrogen stimulation that, it has been suggested, are mediated by eosinophils.
In the absence of oestrogen colloidal carbon induced an increase in the number of eosinophils in mesometrium but not in endometrium with myometrium, and a slight oedematous reaction in deep endometrium. Colloidal carbon abolished the oestrogen-induced increase in the number of eosinophils in endometrium with myometrium and drastically decreased the oestrogen-induced increase in uterine wet weight and the endometrial oedematous responses 6 h after the administration of oestrogen.
The present results agree with the hypothesis that most uterine water imbibition is mediated by eosinophils and suggest a possible mechanism for the interaction of colloidal carbon with eosinophil migration to the uterus.
J. Endocr. (1986) 109, 89–95
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Search for other papers by S. Sepúlveda in
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Search for other papers by A. N. Tchernitchin in
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ABSTRACT
Progesterone pretreatment decreases oestrogen-induced uterine eosinophilia and other non-genomic responses that are possibly mediated by eosinophils. To investigate the mechanisms of this interaction, the present study describes the effects of progesterone on oestrogenic responses already induced by oestrogen treatment and the in-vivo and in-vitro effects of progesterone on blood eosinophils.
Progesterone treatment of oestrogen-pretreated animals potentiated uterine eosinophilia 24 h after progesterone treatment but decreased it at later times and increased eosinophil degranulation in vivo. In addition, progesterone degranulated blood eosinophils in vitro. These findings demonstrate interaction of progesterone with oestrogenic responses mediated by eosinophils.
Progesterone interaction with other oestrogenic responses was analysed for comparison; evidence is shown suggesting a role of eosinophils in oestrogeninduced uterine luminal fluid accumulation.
J. Endocr. (1984) 102, 295–303
