Format

Send to

Choose Destination
Brain Res Mol Brain Res. 2001 Aug 15;92(1-2):115-27.

Persistent corticotropin-releasing factor(1) receptor desensitization and downregulation in the human neuroblastoma cell line IMR-32.

Author information

1
Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA. roseboom@facstaff.wisc.edu

Abstract

Brain corticotropin-releasing factor (CRF) systems integrate various responses to stress. Pathological responses to stress may result from errors in CRF receptor regulation in response to changes in synaptic CRF levels. To establish an in vitro model to study brain CRF receptors, we characterized the CRF-induced modulation of CRF(1) receptors in the human neuroblastoma cell line, IMR-32. Treatment with CRF decreased CRF(1) receptor binding and desensitized CRF-induced increases in cAMP. The decrease in binding had an EC(50) of approximately 10 nM, was maximal by 30 min, and was blocked by the CRF receptor antagonist [D-Phe(12), Nle(21,38), C(alpha)-MeLeu(37)]CRF(12-41). The desensitization was homologous as vasoactive intestinal polypeptide-induced increases in cAMP were unchanged, and elevation of cAMP did not alter CRF(1) receptor binding. Treatment with CRF for up to 24 h did not alter CRF(1) receptor mRNA levels, suggesting that a posttranscriptional mechanism maintains the decrease in receptor binding. Interestingly, recovery of CRF receptor binding and CRF-stimulated cAMP production was only partial following exposure to 100 nM CRF. In contrast, receptor binding recovered to control levels following exposure to 10 nM CRF. These data suggest that exposure to high doses of CRF result in permanent changes characterized by only partial recovery. Identifying the mechanisms underlying this partial recovery may provide insights into mechanisms underlying the acute and chronic effects of stress on CRF receptor regulation.

PMID:
11483248
[Indexed for MEDLINE]

Publication types, MeSH terms, Substances, Grant support

Publication types

MeSH terms

Substances

Grant support

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center