TY - JOUR T1 - Systemic administration of rhIGF-I enhanced regeneration after sciatic nerve crush in mice. JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 1443 LP - 1449 VL - 274 IS - 3 AU - P C Contreras AU - C Steffler AU - E Yu AU - K Callison AU - D Stong AU - J L Vaught Y1 - 1995/09/01 UR - http://jpet.aspetjournals.org/content/274/3/1443.abstract N2 - Despite numerous reports suggesting that insulin-like growth factor-I (IGF-I) may be involved in the survival and regeneration of damaged neurons in vitro and after local administration in vivo, there have been few studies on the effect of IGF-I administered systemically on regeneration of damaged nerves in vivo and the functional consequences of enhanced regeneration. In an earlier study, recombinant human IGF-I (rhIGF-I) administered systemically enhanced the rate of regeneration after a sciatic crush as measured by the number of nerve fibers/muscle section. The purpose of this study was to follow up this finding by evaluating whether rhIGF-I administered peripherally enhances the rate of functional recovery. In this study following nerve injury, mice lost the ability to grip a wire screen with their hind paws and to walk normally as indicated by a decrease in toe spread, internal toe spread and an increase in the angle between hind feet. The ability of injured mice treated with rhIGF-I to grip an inverted screen returned to control levels significantly faster than that of vehicle-treated mice (day 12 vs. day 15, respectively). Similarly, rhIGF-I treatment of injured mice resulted in toe spread, internal toe spread and angle values that were significantly better than that of vehicle-treated mice and returned to control levels faster than vehicle-treated injured mice. There was a parallel loss of innervation after sciatic nerve crush as measured by a loss in choline acetyltransferase activity in the soleus and gastrocnemius muscles.(ABSTRACT TRUNCATED AT 250 WORDS) ER -