Specific receptors for epidermal growth factor in rat intestinal microvillus membranes

Journal Article · Tue Mar 01 00:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6871344

Thompson, J F ^[1]

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1. Tufts Univ. School of Medicine, Boston, MA (USA)

Epidermal growth factor (EGF) is present in high concentrations in milk, salivary, and pancreaticobiliary secretions. EGF, delivered to the intestinal lumen by these fluids, appears to influence intestinal proliferation. Because EGF exerts its mitogenic effect through binding to specific membrane-bound receptors, binding studies of {sup 125}I-labeled EGF to purified microvillus membrane (MVM) preparations fetal, newborn, and adult rat small intestine were performed. Using the membrane filter technique, binding of {sup 125}I-EGF to adult MVM was specific, saturable, and reversible. Adult and fetal MVM binding was rapid and reached a plateau after 30 min at both 20 and 37{degree}C. No binding was detected at 4{degree}C. Specific binding increased linearly from 0 to 75 {mu}g MVM protein. Scatchard analysis revealed a single class of receptors in fetal and adult MVM with an association constant of 1.0 {+-} 0.35 {times} 10{sup 9} and 2.3 {+-} 1.6 {times} 10{sup 9} M{sup {minus}1}, respectively. Binding capacity was 435.0 {+-} 89 and 97.7 {+-} 41.3 fmol {sup 125}I-EGF bound/mg MVM protein for fetal and adult MVM, respectively. Newborn MVM binding was negligible. After binding, cross-linking utilizing disuccinimidyl suberate, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, autoradiography revealed a 170-kDa receptor. These data demonstrate specific receptors for EGF on MVM of rat small intestine and, thus, suggest a mechanism for the intraluminal regulation of enterocyte proliferation by EGF.

• OSTI ID: 6871344
• Journal Information: American Journal of Physiology; (USA), Vol. 254:3; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
EPITHELIUM
CELL PROLIFERATION
GROWTH FACTORS
RADIORECEPTOR ASSAY
RECEPTORS
BIOCHEMICAL REACTION KINETICS
ADULTS
ELECTROPHORESIS
IODINE 125
MILK
MUCOUS MEMBRANES
NEONATES
RATS
SALIVA
SMALL INTESTINE
AGE GROUPS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
FOOD
GASTROINTESTINAL TRACT
INTERMEDIATE MASS NUCLEI
INTESTINES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MEMBRANES
MITOGENS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
TISSUES
TRACER TECHNIQUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques