Erythropoietic response to androgen replacement therapy Erythropoietic and role of IL-6 in aging male rats

ABSTRACT

Changes in iron status and bone marrow Junctions are frequently observed in the elderly. These phenomena are often associated with chronic diseases and/or neoplcfsmas. In a minority of elderly subjects; it is not possible to identify the causes of anemia. This study was carried out to clarify the functional capacity of the erthropoietic tissues of the aged rats, to investigate the role of IL-6 in erthropoietic activity, and to evaluate the short-term testosterone therapy. Thirty healthy male Sprague-Dawley rats were divided according to their age into group I [16-week-old; n = 6], group II [48-week-old; n=12], group III [72-week-old; n=I2]. Six rats enrolled in each elderly group [groups II and III] received s.c. testosterone propionate; 2 mg/100 g body weight every other day for 10 days [Groups lIb and Illb]. The remaining rats not received testesterone were named groups [Ila and IlIa]. One day after the last injection, bone marrow aspirates were performed to evaluate the erthropoietic activity and iron stores in the erythroid precursors. In addition, a peripheral haemogram and determination of serum levels of iron, TIBC, IL-6, and free testosterone were done. Significant age-linked changes were observed in the form of decreased serum levels of free testosterone, IL-6, TIBC, RBCs count, and Hb levels as well as an increase in serum iron level in groups Ila and IIla. Bone marrow hypocellularity with a decrease in the amount of iron storage were especially remarkable in Group IlIa. Moreover improvement in the function of erythropoietic tissues in Group lib indicated by erythroid hyperplasia and an increase in the amounts of iron storage. However, reduced serum IL-6 was not affected by testosterone therapy. These data reveal that senile anemias are of hypoproliferaitue character. Testosterone and IL-6 may be, at least in part, the important factors in determining an age-associated decrease in erythropoiesis