Macromolecular absorption. Mechanism of horseradish peroxidase uptake and transport in adult and neonatal rat intestine.

The immature small intestine of neonatal mammals is permeable to gamma globulins as a source of passive immunity. Allegedly, macromolecular absorption ceases when the epithelial cell membrane matures. However, some evidence exists that adult animals retain a limited capacity to transport antigenic and biologically active quantities of large molecules.

Preparation and characterization of the lateral and basal plasma membranes of the rat intestinal epithelial cell.

A technique is described for the isolation of a plasma-membrane fraction from the rat intestinal epithelial cell which is distinct from the microvillus membrane of that cell. The isolated fraction contains only about 0.2% of the sucrase activity in the original homogenate and negligible quantities of nuclear and mitochondrial membrane markers.

Increased uptake of amino acids and 2-deoxy-D-glucose by virus-transformed cells in culture.

Transformed and nontransformed cells in tissue culture differ in their rate of uptake of certain nutrients, as determined by a polyester-coverslip technique. A 2.5- to 3.

Fat absorption during inhibition of protein synthesis: studies of lymph chylomicrons.

The effect of protein synthesis inhibition on the absorption of oleic acid from micellar solution was studied in mesenteric lymph fistula rats. A micellar solution of oleic acid labeled with tracer doses of oleic acid-(14)C was administered by intraduodenal infusion to rats with indwelling mesenteric lymph cannulas. Protein synthesis was inhibited by intraperitoneal acetoxycycloheximide (ACH), 0.

Isovaleric and -methylbutyric acidemias induced by hypoglycin A: mechanism of Jamaican vomiting sickness.

Hypoglycin A, the causative agent of the Jamaican vomiting sickness, produced a marked increase in concentration of isovaleric acid in the plasma of rats, when administered in a single dose. alpha-Methylbutyric acid, a position isomer, also accumulated. The use of hypoglycin A reproduced some features of human isovaleric acidemia.

Ethanol stimulates triglyceride synthesis by the intestine.

In vivo ethanol given acutely or chronically by two dietary means resulted in significant increases in [1-(14)C]palmitate incorporation into triglyceride by intestinal slices or microsomes derived from intestinal slices. In vitro, 2.6 percent ethanol, an amount comparable to that found in t.