Denervation stimulation of alpha-aminoisobutyric acid uptake by the diaphragm in developing rats

Effect of denervation on accumulation of alpha-aminoisobutyric acid (AIB) by the the diaphragm was studied in 11-, 21-, 31-, and 51-day-old rats. In both innervated and denervated diphragms the accumulation steadily decreased with age. Denervation significantly enhanced accumulation at all ages, the relative increment being greater in older animals owing to the lower basal accumulation ratio for AIB. The denervation-induced stimulation was partially abolished by dactinomycin administration. The drug obviously inhibits the formation of new carrier sites at plasma membranes for AIB transport.