Dietary polyamines are essential luminal growth factors for small intestinal and colonic mucosal growth and development

Abstract

Background: Polyamines are essential for cell growth. Dietary and probably gut bacterial derived polyamines contribute significantly to the polyamine body pool.

Aims: To evaluate the influence of dietary, luminal polyamines on growth and development of different gastrointestinal organs in normally growing rats.

Methods: Male suckling Wistar rats were randomly allocated to four treatment groups: polyamine deficient diet (PDD); PDD plus antibiotics (neomycin 2 g/kg and metronidazole 34 mg/kg); PDD plus polyamine supplementation at normal concentrations; or normal standard laboratory chow. After a six month feeding period 7-10 animals/group were sacrificed.

Results: No differences in body weight gain, food consumption, or general behaviour could be observed between the four groups of animals. Feeding of PDD alone or PDD plus antibiotics resulted in a highly significant decrease in organ weight, protein content, and DNA content in small intestinal and colonic mucosa whereas no alterations were found in the liver.

Conclusions: Long term feeding of polyamine deficient diets resulted in a significant hypoplasia of small intestinal and colonic mucosa. Dietary, luminal polyamines are important local factors for growth and the development of small intestinal and colonic mucosa.

Figure 1

Organ weight of (A) small intestinal mucosa, (B) colonic mucosa, and (C) liver in rats (n=7-10) after a 26 week feeding period with either PDD, PDD + AB, PDD + PA, or standard laboratory chow. Significant differences versus PDD + PA: *p<0.01; †p<0.005.

Figure 2

Protein content of (A) small intestinal mucosa, (B) colonic mucosa, and (C) liver in rats (n=7-10) after a 26 week feeding period with either PDD, PDD + AB, PDD + PA, or standard laboratory chow. Significant differences versus PDD + PA: *p<0.01.

Figure 3

DNA content of (A) small intestinal mucosa, (B) colonic mucosa, and (C) liver in rats (n=7-10) after a 26 week feeding period with either PDD, PDD + AB, PDD + PA, or standard laboratory chow. Significant differences versus PDD + PA: *p<0.01; †p<0.005.