Insulin-induced alterations in the lactoperoxidase-catalyzed radioiodination of membrane proteins of the toad bladder epithelium
Insulin-stimulated sodium transport in the toad urinary bladder consists of two components, a brief element of rapid onset that is independent of protein synthesis, and a sustained increase, slower in onset, that is dependent upon RNA and protein synthesis. The mucosal epithelium of the toad bladder was labeled by lactoperoxidase-catalyzed radioiodination (125I) following 15 min and 3 h exposure to insulin. The membrane of ''mitochondria-rich'' and ''granular'' mucosal cells from these tissues were analyzed by electrophoresis in SDS-urea. Compared to untreated tissues, membranes of ''granular'' mucosal cells from tissues exposed to insulin for 15 min contained a band (Mr . 15,000) with significantly increased labeling. Bladders exposed to insulin for 3 h showed no consistent increase in labeling. These data suggest that there are differences in the conformation of apical membrane proteins during the two phases of hormone-induced sodium transport. The technique may also offer an opportunity to identify ''effector'' proteins mediating this and other insulin responses.
- Research Organization:
- Department of Physiology, Mount Sinai School of Medicine, New York
- OSTI ID:
- 5551293
- Journal Information:
- Endocrinology; (United States), Vol. 109:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BLADDER
PHYSIOLOGY
INSULIN
BIOLOGICAL EFFECTS
IODINE 125
TRACER TECHNIQUES
SODIUM
MEMBRANE TRANSPORT
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
EPITHELIUM
PEROXIDASES
RNA
TOADS
ALKALI METALS
AMPHIBIANS
ANIMAL TISSUES
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
METALS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDOREDUCTASES
PEPTIDE HORMONES
PORPHYRINS
RADIOISOTOPES
REACTION KINETICS
SYNTHESIS
TISSUES
URINARY TRACT
VERTEBRATES
550201* - Biochemistry- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques