Diffusion of labelled substances through isolated rat diaphragm

摘要

1. The rate of diffusion of [¹⁴C] sucrose through rat diaphragm muscle is dependent on the period of preliminary soaking of the muscle in Krebs solution at 36° C. The ratio of the length of the diffusion path through the diaphragm to its geometrical thickness appears to fall from 4·39±0·38 (S.E. of the mean) to 2·23±0·18 after about 6 h of soaking.2. The area of the diaphragms available for diffusion is apparently constant at 0·3-0·4 of their total area.3. The measured thickness of the diaphragms increases by about 20% on soaking.4. Entry of [¹³¹I] iodide into the muscle fibres is detected as a fall in both steady state and non-steady state rates of diffusion through the diaphragm.5. Entry of [¹⁴C-methyl] decamethonium into the muscle cells is not evident from such diffusion studies in normal Krebs solution.