Adrenal cortex hormones and small intestine of adult rat: morphology, purity and enzymatic activities of isolated microvillous vesicles.

An electron microscopic and enzymatic investigation was carried out to assess the purity as well as the morphologic integrity of small intestine microvillous membrane vesicles prepared from the following groups of adult rats: untreated (normals); adrenalectomized and pair-fed controls; treated for 8 days with corticosterone (1 and 10 mg X 100 g-1 body weight X day-1), and relative controls. Electron microscopy observation of ultrathin sections of ruthenium red stained vesicles from all groups showed that the microvillous membranes were structurally intact and virtually uncontaminated by material from other subcellular structures. The vesicles presented a fuzzy, intensely ruthenium red positive layer in their outer membranes. Apparently no alteration was induced in microvillous membrane by adrenalectomy, semistarvation or corticosterone treatment. The values of the enrichment factors for alkaline phosphatase and sucrase were similar for all the groups, indicating a high grade of purity of the preparations. Adrenalectomy and high dose of corticosterone decreased the vesicles content of alkaline phosphatase; sucrase was increased by semistarvation and adrenalectomy.