An immunoelectron microscopic investigation of colstral IgG absorption across the intestine of newborn calves
1994
Jochims, K. | Kaup, F.J. | Drommer, W. | Pickel, M.
The protein A-gold was used to examine the transport of colostral IgG from the lumen of the gut to the circulation in four newborn calves and one 24-hour-old calf. The absorptive enterocytes of the duodenum, jejunum and ileum were investigated five to 60 minutes after administering colostrum, and 24 hours after birth. In the newborn calves, an intracellular micropinocytotic transport of IgG molecules was dominant throughout the entire small intestine. The amount transported increased from the duodenum to the ileum. In addition, evidence of a selective, receptor-mediated transport of IgG during the first few hours of life was provided by the presence of bovine clathrin at the microvillous membrane of the duodenal and jejunal enterocytes, indicating the existence of specialized vesicles for transport, the so-called 'coated' vesicles. No sign of paracellular transport was detected. Intestinal closure was interpreted as a multifactorial event comprising the replacement of the fetal intestinal epithelial cells by more mature populations, the initial cessation of transport at the basal and lateral cell membrane of the absorptive enterocytes, and an increase in intracellular proteolytic activity by lysosomes.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by National Agricultural Library