Polyamine concentration in rat milk and food, human milk, and infant formulas.

The polyamine concentration in rat milk and food, human milk, and infant formulas was estimated by HPLC. In rat milk, the concentration of putrescine and spermine was low (generally under 2.5 nmol.mL-1 for putrescine and under 1 nmol.mL-1 for spermine). The spermidine concentration was higher and seemed to increase during lactation. The rat food was richer in polyamines than the rat milk (about 150 times for putrescine and spermine, about 30 times for spermidine). We already proved that ingestion of spermine or spermidine can induce precocious maturation of the rat intestine. The present observations suggest that polyamines contained in rat food could play an important role in postnatal maturation of the rat intestine. The polyamine concentration of human milk was measured from 60 different mothers during a period extending from the 1st wk to the 6th mo of lactation. Great variation was observed. During the 1st mo of lactation, the general pattern was as follows: putrescine concentration generally varied little (from 1 to 3 nmol.mL-1), spermine and spermidine concentrations showed a similar pattern (the highest values appeared at the end of the 1st wk of suckling). After the 4th mo of lactation, putrescine concentration increased slightly, whereas spermine and spermidine concentration stayed almost stable. The concentrations of polyamines in 18 powdered milks for babies were estimated. Spermine and spermidine contents were lower than those in human milk. A protective effect of spermine or spermidine against alimentary allergies is suggested.