Role of nucleosides and nucleotide mixture in intestinal mucosal growth under total parenteral nutrition

The preventive effect of a mixture of nucleosides and a nucleotide (OG-VI) on total parenteral nutrition (TPN)-associated gut mucosal atrophy was investigated. Male Wistar rats were randomly divided into two groups. The TPN group (n = 11) received a standard TPN diet (250 kcal and 1.78 g nitrogen.kg-1.day-1) for 6 days; the TPN + OG-VI group (n = 10) received OG-VI (2.5 ml.kg-1.day-1) in addition to the standard TPN solution for 6 days. To obtain information on a normal fed condition of the intestine, another 10 rats were maintained on oral rat chow for 6 days. Compared with the TPN group, mucosal wet weights in the jejunum (22.8 +/- 1.8 vs. 20.5 +/- 2.0 mg/cm) and the ileum (19.4 +/- 2.2 vs. 16.8 +/- 2.3 mg/cm) were significantly greater in the TPN + OG-VI group. Likewise, diamine oxidase activities in the jejunum (13.7 +/- 4.27 vs. 8.02 +/- 3.40 nmol.min-1.cm-1) and the ileum (33.9 +/- 6.89 vs. 25.9 +/- 7.93 nmol.min-1.cm-1) were significantly higher in the TPN + OG-VI group. Moreover, the bromodeoxyuridine labeling index in the TPN + OG-VI group (36.9 +/- 4.30%) was significantly higher than in the TPN group (31.0 +/- 3.03%). The addition of OG-VI to the standard TPN diet improved mucosal growth and maturity by increasing the proliferating activity of crypt cells. External provision of purines and pyrimidines may be necessary to sustain mucosal function during TPN.