Premium
Gonadotropin‐releasing Hormone Agonist Administration Affects the Thymopoiesis in Adult Female Rats Independently on Gonadal Hormone Production
Author(s) -
Leposavić Gordana,
Pekić Sandra,
Kosec Duško
Publication year - 2005
Publication title -
american journal of reproductive immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.071
H-Index - 97
eISSN - 1600-0897
pISSN - 1046-7408
DOI - 10.1111/j.1600-0897.2004.00244.x
Subject(s) - endocrinology , medicine , thymocyte , t cell receptor , biology , hormone , cd8 , agonist , flow cytometry , cd3 , receptor , t cell , immunology , antigen , immune system
Problem: In addition to having an indirect effect on the T‐cell development by controlling the production of ovarian steroids, an accumulating body of evidence suggest that GnRH analogue (GnRH‐A) administration may exert a thymopoietic regulatory effect that is not mediated by ovarian hormones. Method of study: In non‐ovariectomized (non‐OVX) and OVX adult female AO rats treated s.c. with GnRH‐A or saline (controls), over 14 days, were estimated the thymic cellularity and thymocyte expression of CD4/CD8/TCR α β by stereological analysis and three‐color flow cytometry, respectively. Results: GnRH‐A in both groups of rats diminished the thymic cellularity. In non‐OVX rats GnRH‐A increased the relative numbers of immature cells (CD4‐8‐TCR α β − , CD4‐8‐TCR α β low and CD4+8‐TCR α β low ), and reduced those of positively selected CD4+8+TCR α β high and mature (CD4‐8+TCR α β high , CD4+8‐TCR α β high ) cells, suggesting decelerated expression of TCR α β followed by less efficient positive selection and further maturation of the selected cells. Differently, in OVX rats GnRH‐A decreased the percentage of immature (CD4‐8‐TCR α β − , CD4+8+ TCR α β − ) cells and increased those of all TCR α β high subsets, suggesting an increased rate of early thymocyte differentiation, more efficient positive selection and further maturation of the selected cells. Conclusions: The effect of GnRH‐A administration is affected by the presence of ovarian steroids.