|
|
||||||||
AJP - Endocrinology and Metabolism, Vol 255, Issue 4 E504-E512, Copyright © 1988 by American Physiological Society
ARTICLES |
D. J. Pillion, J. F. Haskell and E. Meezan
Department of Pharmacology, University of Alabama, Birmingham 35294.
Purified preparations of renal glomeruli and tubules were obtained by a procedure involving perfusion of rat kidneys with magnetic iron oxide particles to selectively separate the iron-containing glomeruli from the nonmagnetic tubules. Detergent-soluble extracts of both renal glomerular and tubular membranes showed high-affinity, specific binding of 125I-labeled insulin-like growth factor I (125I-IGF-I), whereas degradation of this peptide hormone was minimal during a 90-min incubation at 22 degrees C in the presence of 2.5 mM EDTA and 5 mM N-ethylmaleimide. The affinity of these receptors for IGF-I appeared identical in the two types of renal tissue, since 50% inhibition of 125I-IGF-I binding to both glomerular and tubular tissue occurred in the presence of approximately 3 x 10(-9) M unlabeled IGF-I. In contrast, insulin was much less effective at blocking 125I-IGF-I binding to either tissue, with 1 x 10(-6) M insulin required to produce 50% inhibition of binding. Relative to 125I-IGF-I binding, 125I-insulin binding to glomerular and tubular tissue was significantly lower per milligram protein. 125I-IGF-I was specifically cross-linked to a glomerular receptor subunit that migrated as two discrete bands with relative molecular weight (Mr) of 140,000-150,000 on sodium dodecyl sulfate polyacrylamide gels in the presence of 40 mM dithiothreitol. In contrast, 125I-IGF-I was cross-linked to a tubular receptor subunit that migrated as two discrete bands but at a slightly different position, with Mr of 120,000-140,000.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
D. Senthil, G. G. Choudhury, H. E. Abboud, N. Sonenberg, and B. S. Kasinath Regulation of protein synthesis by IGF-I in proximal tubular epithelial cells Am J Physiol Renal Physiol, December 1, 2002; 283(6): F1226 - F1236. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Desnoyers, R. A. Simonette, R. L. Vandlen, and B. M. Fendly Novel Non-isotopic Method for the Localization of Receptors in Tissue Sections J. Histochem. Cytochem., December 1, 2001; 49(12): 1509 - 1518. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. De la Puente, L. Goya, S. Ramos, M. A. Martin, C. Alvarez, F. Escriva, and A. M. Pascual-Leone Effects of experimental diabetes on renal IGF/IGFBP system during neonatal period in the rat Am J Physiol Renal Physiol, December 1, 2000; 279(6): F1067 - F1076. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |