Autoradiographic assessment of 3H-proline uptake by osteoblasts following guanethidine-induced sympathectomy in the rat.

Sympathectomy was carried out in rats by injections of guanethidine-sulfate from birth to 14 days of age. At 45 days of age, the activity of osteoblastic cells was monitored by 3H-proline autoradiography. Effectiveness of sympathectomy was verified by light-microscopic examination of superior cervical and celiac ganglia. Grain counts over periosteal osteoblasts of the femoral diaphysis and osteoblasts mesial to the first molar in the mandible demonstrated a significant reduced uptake of 3H-proline in the sympathectomized rats. The data provide direct evidence of sympathetic influence on osteoblastic activity and suggest that sympathectomy may result in the loss of a trophic influence which is important in the regulation of osteogenesis.