Failure to demonstrate morphologically the presence of colostral or milk cells in the wall of the gastrointestinal tract of the suckling neonatal mouse.
The possibility that intact cells may migrate from ingested colostrum and milk into the gut wall of the nursing neonate has been tested directly by means of radioautographic techniques. [3H]Thymidine was continuously infused into female mice throughout the last 6 days of their pregnancy. Upon delivery, their fully [3H]thymidine-labelled litters were removed and given to nurse from unlabelled surrogate mothers whose own litters were borne simultaneously. These unlabelled litters were similarly removed immediately upon birth and given to the [3H]thymidine-infused mothers to nurse. Infants labelled during gestation and mothers labelled during pregnancy continued to receive thrice-daily injections of isotope for 1-14 days and 1-18 h, respectively, after delivery. The stomach and adjacent portion of small intestine were removed from unlabelled infants nursing from labelled surrogate mothers at intervals of 1-18 h after beginning to suckle, subserially sectioned and prepared for radioautography. From days 1 to 14 after beginning to suckle, the same tissues were removed from labelled infants nursing from unlabelled surrogate mothers and similarly prepared for radioautography. The results indicate that transepithelial migration of intact cells of the colostrum and milk does not appear to be the method by which immunological functions are adoptively transferred to the nursing neonatal mouse.
D000818:Animals; D000831:Animals, Newborn; D003126:Colostrum / Q000166:cytology*; D004064:Digestive System / Q000166:cytology*; D005260:Female; D008214:Lymphocytes / Q000166:cytology; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008892:Milk / Q000166:cytology*; D011247:Pregnancy; D013391:Sucking Behavior