Effect of putrescine on oxyntic gland and colonic mucosal growth in rats

The effect of putrescine on oxyntic gland and colonic mucosal growth was studied by measuring the rate of [3H]-thymidine incorporation into mucosal DNA in vitro (DNA synthesis) and DNA, RNA and protein content of the mucosa following intramuscular injections of the compound (50 mumoles/100g). Saline injected animals served as controls. Multiple injections of putrescine during a 2-day fast produced a significant enhancement of mucosal DNA synthesis in oxyntic gland and colonic mucosa, with no apparent change in DNA, RNA or protein content in either of the tissues, compared to the corresponding saline-controls, when measurements were made 12-24 h after the last injection. However, when the animals were killed after 4 days, DNA, RNA and protein content of oxyntic gland mucosa, and DNA and protein content of colonic mucosa were found to be significantly higher than in the respective saline-controls. We conclude that putrescine, taken up from the blood, can stimulate growth of gastrointestinal mucosa.