Role of polyamines and intracellular pH change in the hypertrophy of the denervated rat hemidiaphragm.
The transient hypertrophy of the denervated rat hemidiaphragm is associated with a rise in concentrations of putrescine and spermidine. Hypertrophy still occurs following denervation in rats injected with difluoromethylornithine which reduces the increase in spermidine and particularly putrescine levels. Administration of isobutylmethylxanthine tended to raise putrescine concentrations in the denervated but not innervated tissue. No evidence could be found that the enhanced protein synthesis rate in the denervated tissue is associated with an increase in intracellular pH.