Distribution of water between extracellular and intracellular compartments of incised wounds of rabbits.

The distribution of water between the extracellular and intracellular compartments in incised wounds of skin, muscle and stomach has been studied in healthy rabbits and the progress of healing monitored by the determination of tensile strength for 120 days. It has been shown that, after wounding, there is an immediate expansion of the extracellular space. The increase is most marked during the first 24 hours and is maximal by this time in wounds of the skin and the muscle. During the first 30 days of healing, all incised tissues contain similar amounts of extracellular water which constitute approximately one-half of the total tissue mass, irrespective of the size of the extracellular space prior to wounding. There is an inverse relationship between the increase in the amount of extracellular water and the size of the extracellular space prior to wounding. All incised tissues maintain an elevated, and similar, concentration of extracellular water for more than 120 days. The period of maximal gain in tensile strength corresponds to the period of maximal expansion of the extracellular space which signifies a particularly active phase in the wound healing process. The intracellular space in wounds of muscle and stomach is reduced for more than 120 days, but no significant changes are seen in the intracellular water of wounds of skin. It has been concluded that expansion of the extracellular space is essential for wound healing, and it can, therefore, serve as a sensitive indicator of tissue injury.