Local injection of insulin-zinc stimulates DNA synthesis in skin donor site wound.
Our group has reported the ability of local insulin-zinc injection to accelerate skin wound healing. This experiment was conducted to investigate the metabolic mechanisms of locally injected insulin-zinc in accelerating wound healing. A partial thickness skin donor site wound was created on the back, and indwelling catheters were placed in the carotid artery and jugular vein in anesthetized rabbits. On day 7 after injury, the wound was either injected with 0.2 U of insulin-zinc, 0.4 microg zinc (the amount of zinc in 0.2 U of insulin-zinc), or not injected; stable isotope tracers were infused for measurement of wound DNA synthetic rate as a reflection of cell proliferation. Wound protein synthetic and breakdown rates were also measured. The local insulin-zinc injection increased wound insulin concentration from below 5 pmol/L to 1,260+/-780 pmol/L with minor changes in blood glucose concentration that did not require exogenous glucose replacement. In the insulin-zinc-injected wound, the total DNA synthetic rate was increased by approximately 50% (p<0.05 vs. control). In the zinc-injected wound, whereas total DNA synthetic rate was increased (p<0.05 vs. control), net protein deposition (synthesis-breakdown) was less (p<0.05) than those in the control and insulin-zinc groups. We conclude that local insulin-zinc injection stimulates wound DNA synthesis, which would be expected to accelerate wound reepithelialization.
Zhang
Xiao-jun
XJ
Metabolism Unit, Shriners Hospital for Children, Department of Surgery, University of Texas Medical Branch, Galveston, TX 77550, USA. xzhang@utmb.edu
Chinkes
David L
DL
Sadagopa Ramanujam
V M
VM
Wolfe
Robert R
RR
D000818:Animals; D004247:DNA / Q000096:biosynthesis*; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007271:Injections, Intradermal; D007328:Insulin / Q000032:analysis; D049528:Insulin, Long-Acting / Q000008:administration & dosage*; D008297:Male; D011817:Rabbits; D012867:Skin / Q000737:chemistry; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology
D007004:Hypoglycemic Agents; D007328:Insulin; D049528:Insulin, Long-Acting; D004247:DNA