Serum somatomedin C concentrations following pneumonectomy.

Because a somatomedinlike substance appears in rabbit serum 9 days after pneumonectomy, which has the capacity to make cultured type II cells incorporate 3H thymidine into DNA, we measured serum immunoreactive somatomedin C concentrations following pneumonectomy, nephrectomy, and sham operation (thoracotomy). We found no striking differences in somatomedin C levels between the 3 groups at 5, 9, 13, 17, and 21 days postsurgery, indicating that somatomedin-C and the serum postpneumonectomy factor are unlikely to be the same. Serum somatomedin-C concentrations, however, rose following surgery in all groups, suggesting that serum somatomedin-C responds to surgical wounding. We speculate that the increase in serum somatomedin-C reflects production of somatomedin-C by the healing tissue.