No Direct Mitogenic Effect of Sex Hormones on Antlerogenic Cells Detected in Vitro

Deer antler – A novel model for studying organ regeneration in mammals

“…This finding, together with the results obtained using autoradiography and an in vitro binding assay (Li et al, 2001b), demonstrate that androgen signaling is also involved in antler regeneration through binding to AR. However, the mechanism conveying the communication between androgens and growth factors in regulating the transformation from pedicle to antler is not known.…”

“…Subsequently, the same team (Suttie et al, 1988) found that plasma concentrations of IGF-1 were significantly elevated in stags after their growing antlers were removed, indicating that antlers were the target, rather than the source of circulating IGF-1. Supporting this notion, both Type I and Type II IGF receptors have been identified in the antler growth centers (Elliott et al, 1992(Elliott et al, , 1993, and the mitogenic effects of IGF-1 have been shown to be dosedependent on the growth of mesenchymal cells isolated from the antler tip (Price et al, 1994;Sadighi et al, 1994), the AP cells (Li et al, 1999(Li et al, , 2001b, and the PP cells in serum-free culture (unpublished data).…”

Pedicle and first antler formation in deer: Anatomical, histological, and developmental aspects

“…Compared to periosteum from other cranial sites, the AP contains a higher number of androgen binding sites , pointing to a local stimulatory effect of the androgens on the AP. Recent studies by LI et al (2001b), however, showed that in vitro androgens do not exercise a mitogenic effect on antlerogenic periosteal cells. From this LI et al (2001b) concluded that pedicle formation is not brought about by direct androgenic stimulation of the antlerogenic periosteal cells, but that androgens may only increase the sensitivity of these cells to certain growth factors.…”

“…Recent studies by LI et al (2001b), however, showed that in vitro androgens do not exercise a mitogenic effect on antlerogenic periosteal cells. From this LI et al (2001b) concluded that pedicle formation is not brought about by direct androgenic stimulation of the antlerogenic periosteal cells, but that androgens may only increase the sensitivity of these cells to certain growth factors. According to BUBENIK (1983), pedicle formation requires interaction between the AP and hypothetical 'antler growth centers' located in the brain.…”

Antler growth rate in yearling Iberian red deer (Cervus elaphus hispanicus)

“…This process is under the control of several factors, both hormonal, e.g. insulin-like growth factor-1 (IGF-1; Li et al 2001) and not hormonal, e.g., the photoperiod (Suttie et al 1998). For first antlers, Goss (1969) stated that the chronological age is one of the most important factors that control this process.…”