Polyamines in the gastro-intestinal tract of goat kids and in the regenerating ruminal epithelium of sheep

The aim of the present study was to investigate whether temporal changes in polyamine concentration and synthesis could be found in the luminal conten t and wall tissue of the rumen and abomasum, two organs which have entirely different growth patterns during the first month of life. In the abomasal mucosa there was a marked gradual decrease in the ornithine decarboxylase ( ODC) activity during the first month of life, while the ODC activity in the ruminal mucosa was low during the whole experimental period. However, inju ry of the rumen wall was followed by increased ODC activity. The ODC activi ty in duodenal mucosa was about 10 times higher than in the ileal mucosa an d the ruminal epithelium. In ruminal liquid a clear peak in ODC activity wa s observed during the period 51-70 days after birth. The polyamine concentr ation did not parallel the ODC activity, in either the ruminal epithelium o r the ruminal liquid. Of the polyamines, the spermine concentration was alw ays highest, and with the exception of duodenal mucosa, the putrescine conc entration was lowest. In liver a clear decrease in spermidine concentration from day 1 to about day 60 after birth was observed. Otherwise no marked t emporal changes in tissue polyamine concentrations were observed. Two and a half hours after oral administration of C-14-labelled spermine, nearly all of the radioactivity was found in the lumen of the gastrointestinal tract. On the other hand, 1 h after intravenous injection of polyamines the walls of the gastrointestinal tract were strongly labelled. In conclusion, the p olyamines needed for ruminal epithelial development seem to come from sourc es other than the ruminal epithelium itself or the ruminal lumen.