Hematopoietic stem cell antigen-1 (Sca-1) expression in different lymphoid tissues of female mice treated with GnRH agonist.
OBJECTIVE
Our earlier studies have demonstrated a general suppression of leukocyte maturation upon GnRH agonist treatment in mice and suggested a potential effect at an early stem cell stage of leukocyte development.


METHODS
Three-week old Balb/c and C57BL/6 female mice received 50 micrograms injections of Lupron depot or placebo. Sequential changes in Sca-1+ cells in the bone marrow, thymus, blood and spleen were studied by flow cytometry.


RESULTS
In bone marrow, the absolute numbers of Sca-1+ cells were significantly decreased at 2 weeks in C57BL/6 mice whereas a decreasing trend was noted in Balb/c mice following agonist administration. Concomitantly, thymocytes expressing Sca-1+ cells were significantly increased at 2 weeks in C57BL/6 mice, but were significantly decreased in Balb/c mice. Significant decreases in Sca-1+ cells were also observed in spleen and blood in Balb/c mice whereas no significant differences were observed in C57BL/6 mice.


CONCLUSIONS
These data suggest GnRH agonists affect hematopoietic stem cell development in mice. The effects observed vary with different genetic backgrounds. In Balb/c mice these effects are more pronounced, and appear to result in the inhibition of stem cell maturation. In contrast, GnRH agonist enhances stem cell maturation in C57BL/6 mice.
Rao
L V
LV
Department of Obstetrics and Gynecology, Case Western Reserve University, Cleveland, OH, USA.
Cleveland
R P
RP
Kimmel
R J
RJ
Ataya
K M
KM
D000818:Animals; D000950:Antigens, Ly / Q000096:biosynthesis*; D001835:Body Weight / Q000187:drug effects; D001853:Bone Marrow / Q000187:drug effects; D002452:Cell Count / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists* / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology*; D007962:Leukocytes / Q000187:drug effects; D016729:Leuprolide / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects; D008221:Lymphoid Tissue / Q000187:drug effects* / Q000276:immunology*; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009929:Organ Size / Q000187:drug effects; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects; D013950:Thymus Gland / Q000187:drug effects; D014599:Uterus / Q000187:drug effects
D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D016729:Leuprolide