TY - JOUR

T1 - On the transfer of serum proteins to the rat intestinal juice.

AU - Andersen, Vibeke

AU - Norén, Ove

AU - Poulsen, Mona D

AU - Sjöström, H

AU - Hansen, Gert Helge

AU - Olsen, Jørgen

N1 - Keywords: Animals; Biological Transport; Blood Proteins; Immunoelectrophoresis, Two-Dimensional; Immunoglobulins; Immunohistochemistry; Intestinal Mucosa; Intestinal Secretions; Male; Molecular Weight; Orosomucoid; RNA; Rats; Rats, Wistar; Serum Albumin; Transferrin; alpha 1-Antitrypsin

PY - 1994

Y1 - 1994

N2 - The in vivo pattern of serum proteins in the rat small-intestinal juice was characterized by crossed immunoelectrophoresis. Immunoglobulins and albumin, alpha-1-antitrypsin, transferrin, and orosomucoid were present. Larger serum proteins were absent (ceruloplasmin, haptoglobin, alpha-1-macroglobulin, alpha and beta lipoproteins). Thus, apart from immunoglobulins, only serum proteins with a molecular mass less than approximately 100 kDa were demonstrated. The origin and epithelial transfer were further characterized, using albumin as a model. No sign of local synthesis of albumin by the enterocytes was found by Northern blotting, and no albumin was found in the Golgi complex by immunogold electron microscopy. By immunogold electron microscopy a heavy labelling of albumin was observed in the interstitial spaces between the villus enterocytes. Where the enterocytes disintegrated, albumin was seen to leak out into the intestinal lumen from the opened interstitial spaces. A weak labelling was also found in the lysosomal/endosomal-like structures, especially in the crypt enterocytes, indicating pinocytosis of albumin. We conclude that the main reason for the occurrence of certain serum proteins in the intestinal juice is a selective passage through the capillary wall followed by passive intercellular transport via delivery of the serum in the interstitial space during disintegration of the enterocytes.

AB - The in vivo pattern of serum proteins in the rat small-intestinal juice was characterized by crossed immunoelectrophoresis. Immunoglobulins and albumin, alpha-1-antitrypsin, transferrin, and orosomucoid were present. Larger serum proteins were absent (ceruloplasmin, haptoglobin, alpha-1-macroglobulin, alpha and beta lipoproteins). Thus, apart from immunoglobulins, only serum proteins with a molecular mass less than approximately 100 kDa were demonstrated. The origin and epithelial transfer were further characterized, using albumin as a model. No sign of local synthesis of albumin by the enterocytes was found by Northern blotting, and no albumin was found in the Golgi complex by immunogold electron microscopy. By immunogold electron microscopy a heavy labelling of albumin was observed in the interstitial spaces between the villus enterocytes. Where the enterocytes disintegrated, albumin was seen to leak out into the intestinal lumen from the opened interstitial spaces. A weak labelling was also found in the lysosomal/endosomal-like structures, especially in the crypt enterocytes, indicating pinocytosis of albumin. We conclude that the main reason for the occurrence of certain serum proteins in the intestinal juice is a selective passage through the capillary wall followed by passive intercellular transport via delivery of the serum in the interstitial space during disintegration of the enterocytes.

M3 - Journal article

C2 - 7518612

VL - 29

SP - 430

EP - 436

JO - Scandinavian Journal of Gastroenterology

JF - Scandinavian Journal of Gastroenterology

SN - 0036-5521

IS - 5

ER -