ROLE OF SERUM NONSUPPRESSIBLE INSULIN-LIKE ACTIVITY (NSILA) IN WOUND-HEALING - .1. INFLUENCE OF THYROPARATHYROIDECTOMY ON SERUM NSILA AND WOUND-HEALING IN RAT

  • 1 January 1976
    • journal article
    • research article
    • Vol. 80  (5) , 608-616
Abstract
Serum contains a 90,000 MW glycoprotein that exhibits insulin-like activity on adipocytes, skeletal muscle and fibroblasts in tissue culture; this protein is physicochemically and immunochemically distinct from insulin and is termed nonsuppressible insulin-like activity (NSILA). The response of serum NSILA to thyroparathyroidectomy (TPTHX) was assessed, and this response was associated with tissue repair processes in the injured rat. NSILA probably modulates the fibroblastic response in wound healing. TPTHX decreased NSILA to 40% of control levels (P < 0.001); 90 male animals subsequently were wounded by a 10% 3rd-degree burn or skin excision. Following injury, NSILA significantly increased in control and TPTHX groups, but this acute-phase response was attenuated in TPTHX animals. Light microscopy of granulation tissue demonstrated a diminution in the fibroblastic response in TPTHX animals. Hydroxyproline analysis of granulation tissue revealed a significant decrease (P < 0.025) in collagen content in TPTHX animals with low NSILA levels. Serum NSILA levels probably are controlled, in part, by thyroid hormone and NSILA may modulate the fibroblastic response of connective tissue repair processes.