The pH of Inflammatory Exudates

Inflammatory exudates were collected at various times in small chambers adhered over skin wounds of normal rabbits. The exudate pH was compared with the blood pH. At termination of each experiment the lesions were excised for histologic study. The blood pH remained unchanged. The pH of the exudate decreased with time showing a definite fall at 24 hr and reaching the lowest value at 72 hr without appreciable further change at 96 hr. The inflammatory cell response in the lesions was slight. Exudation of cells had subsided at 24 hr and thereafter only reparative processes were present. An increase of the H-ion concentration apparently confined to the lesion occurred within the first 24 hr of inflammation and persisted during wound healing. A correlation between the histology of the inflammatory reaction and the pH of the exudate was not apparent.