Changes in diamine and polyamine metabolism in the duct-ligated submaxillary and sublingual glands of the rat.

Duct-ligation of salivary glands is known to cause disappearance of acini, while ductal elements persist. In the present investigation the duct-ligated submaxillary and sublingual glands increased in weight by 45-60% 3 days postoperatively, while they weighed 48-56 and 63-64% less than their contralateral glands 10 and 21 days postoperatively. In the duct-ligated glands putrescine increased markedly both in terms of total amount and in terms of concentration, while spermidine and spermine decreased; histamine, in terms of concentration, was initially reduced but increased markedly later. As to total amount histamine tended to increase along time. The histamine-forming enzyme, histidine decarboxylase, and the putrescine-forming enzyme, ornithine decarboxylase, showed higher activities in the duct-ligated submaxillary glands than in the contralateral glands. Di- and polyamines and their synthesizing enzymes are considered to increase in growing tissue. The present results of increased amine levels and enzyme activities are discussed in relation to previous findings of ductal goblet cell hyperplasia following duct-ligation and of increases of polyamines in cystic fibrosis.