Ovariectomy augments b lymphopoiesis and generation of monocyte/
macrophage precursors in rat bone marrow.
Erben, Reinhold G., Sylvia Raith, Johannes Eberle, and Manfred
Stangassinger.
Institute of Physiology, Physiological Chemistry and Animal
Nutrition,
APStracts 4:0265E, 1997.
To investigate the effects of estrogen depletion on hematopoiesis and
bone turnover, female rats were either ovariectomized (OVX) or sham
-operated (SHAM), and sacrificed at 1, 2, 3, and 4 weeks postsurgery.
Flow cytometric analysis of bone marrow cells (BMC) revealed that in
close temporal association with the rise in bone turnover as measured
by bone histomorphometry the number of Thy 1.1+ and KiB1R+ BMC in
creased two- to threefold in OVX rats relative to SHAM controls. The
Thy 1.1+ BMC were further characterized as Thy 1.1+/KiB1R+ and Thy
1.1+/HIS24+ double positive cells of the B cell lineage. A transient
rise in ED1+ myeloid cells expressing a lysosomal antigen specific
for the monocyte/macrophage and os teoclast lineage coincided with
the up-regulation of osteoclast numbers in OVX rats at two weeks
postsurgery, but the number of ED8+ myelomonocytic BMC remained
unchanged. Administration of estradiol prevented the rise in Thy
1.1+, KiB1R+, and ED1+ BMC in OVX animals. Our study indicates that
ovariectomy up-regulates B lymphopoiesis in rat bone marrow, and
increases myeloid cell differentiation into the monocyte/macrophage
and possibly also the osteoclast lineage.
Received 6 October 1997; accepted in final form 18 November 1997.
APS Manuscript Number E469-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 December 1997