Effect of testosterone on binding of insulin-like growth factor-I (IGF-I) and IGF-II in growing antlers of fallow deer (Dama dama).
Testosterone regulation of antler growth may be via the insulin-like growth factors (IGFs). Using histological autoradiography we have measured the specific binding of IGF-I and IGF-II to antler sections during normal growth and during the maturation which follows testosterone treatment of adult fallow deer. In antlers from 20 to 100 days following casting, IGF-I binding was constant within each histological region until 80 days. Between this time and 100 days there was decreased binding to chondrocytes (P < or = 0.01) and increased binding to the reserve mesenchyme/perichondrium (P < or = 0.001). Following testosterone treatment, IGF-I binding declined in dermis (P < or = 0.05), reserve mesenchyme/perichondrium (P < or = 0.05), and chondroblasts (P < or = 0.01). Specific binding of IGF-II showed no change during normal or testosterone-stimulated growth. In conclusion, the regulation of antler maturation by testosterone may include IGF action, probably via the Type 1 IGF receptor.
Elliott
J L
JL
Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.
Oldham
J M
JM
Asher
G W
GW
Molan
P C
PC
Bass
J J
JJ
D000818:Animals; D000999:Antlers / Q000254:growth & development* / Q000378:metabolism*; D001345:Autoradiography; D003670:Deer / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D017527:Receptor, IGF Type 2 / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology*
D007457:Iodine Radioisotopes; D017527:Receptor, IGF Type 2; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II