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THE PERMEABILITY TO 131 I‐PVP OF THE NORMAL AND HYPERTROPHIED GASTRO‐INTESTINAL TRACT OF SHEEP
Author(s) -
Fell B. F.,
Regoeczi E.,
Campbell Rosa M.,
Mackie W. S.
Publication year - 1969
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1969.sp002013
Subject(s) - medicine , endocrinology , plasma clearance , muscle hypertrophy , alimentary tract , involution (esoterism) , small intestine , weaning , catabolism , weanling , albumin , biology , chemistry , metabolism , pharmacokinetics , consciousness , neuroscience
The permeability to 131 I‐PVP of the gastro‐intestinal tract was studied in non‐breeding ewes, in post‐parturient ewes with alimentary hypertrophy, and in post‐weaning ewes in which the enlarged intestines were undergoing involution. A method for measuring the clearance of 131 I‐PVP from the plasma by the gastro‐intestinal tract is presented and is shown to be more sensitive than that of expressing faecal radioactivities as a fraction of the intravenous dose. The clearance of 131 I‐PVP by the gastro‐intestinal tract in non‐breeding ewes was 4·29 per cent of the total clearance from the blood; during the development of alimentary hypertrophy the clearance was 5·09 per cent, and in a group with maximum hypertrophy, 4·91 per cent. These increases were not statistically significant (P〉0·01, but 〈0·05), but the mean clearance value of 6·81 per cent during the atrophy of the intestinal mucosa was significantly higher than the corresponding value in any other group (P〈0·01). The clearance of 131 I‐PVP from the plasma via the bile and pancreatic secretions in two normal sheep was equal to about 2 per cent of the total plasma clearance of PVP. It is concluded that the increase in permeability during the post‐weaning atrophic phase of the gut is probably insufficient to cause marked alterations in the catabolism of plasma proteins. The half‐life of serum albumin was measured in both lactating and non‐breeding ewes, and the conclusion that gastro‐intestinal hypertrophy in the lactating ewe is not accompanied by a significant increase in permeability to macromolecules is supported by the finding that the half‐life of serum albumin is not affected by lactation.