Nonelectrolyte Transport in Muscle during Induced Protein Loss

The accelerated loss of protein from Rana pipiens sartorius muscle following the induction of rigor by 100 millimolar 1-pentanol is not accompanied by increase in the rate constant for the efflux of urea. This observation is not readily accounted for by classical lipid-pore membrane permeability models. Alternative models are considered, in which protein and nonelectrolyte transport are dissociated; the dissociation could be (i) topological, due to compartmentalization, or (ii) functional, for example, if protein loss were due to change of the state of intracellular protein or if urea transport were limited by diffusion in the cytoplasm.