Henry Ford Hospital Medical Journal


Harold M. Frost


The regional acceleratory phenomenon (RAP) is a complex reaction of mammalian tissues to diverse noxious stimuli. The phenomenon occurs regionally in the anatomical sense, involves both soft and hard tissues, and is characterized by an acceleration and domination of most ongoing normal vital tissue processes. It may represent an "SOS" mechanism which evolved to potentiate tissue healing and local tissue defensive reactions. When a RAP is obtunded, retarded healing and lowered resistance to infection and mechanical abuse may ensue. When ignored in experimental design, the phenomenon can seriously perturb studies of metabolic bone disease and of the effects of mechanical, endocrinologic, and biochemical factors on skeletal physiology.