Distribution of blood flow within the skin of the rabbit with particular reference to hair growth.

• Isotopic clearance techniques using radioactive inert gases have permitted assessment of the capillary blood flow in a number of organs. In certain organs, such as heart and testis, the clearance curve is a monotonic exponential function suggesting uniform distribution of the capillary blood flow. However, in other organs such as the kidney, the clearance curve can be analyzed into a number of separate exponents indicating nonuniform distribution. In the present paper the krypton (Kr) clearance technique has been used to examine the nutrient circulation in the skin of the rabbit. Preliminary experiments indicated that the clearance curve was bimodal. The relationship of this bimodal clearance to several physiological parameters, in particular the hair growth cycle, has been examined.