title: Dimethyl sulfoxide decreases specific EGF binding.
abstract: Dimethyl sulfoxide (DMSO) stimulates tyrosine phosphorylation of the hepatic EGF receptor in isolated membrane preparations. To determine whether DMSO affects EGF binding, primary cultures of rat hepatocytes were incubated with 1-10% DMSO for 30 min prior to the addition of 125I-EGF. DMSO (1-2%) reduced specific 125I-EGF binding; the effect was maximal (a 40-60% reduction) at 5-7.5% DMSO and was reversed by removing the DMSO. Scatchard analysis showed that the reduction in binding was due to a change in receptor affinity. The decrease in binding was not seen when other, slightly less polar, solvents (eg, acetone and ethanol) were tested. DMSO also reduced 125I-EGF binding to purified rat liver plasma membranes. This reduction was seen in the absence of added ATP and in membranes that had been pretreated with TLCK, a tyrosine kinase inhibitor. Thus, completion of the receptor autophosphorylation reaction was not necessary to effect the change. The data are consistent with a DMSO-induced alteration of receptor conformation that reversibly reduces receptor affinity.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000187:drug effects; D002478:Cells, Cultured; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D011956:Receptors, Cell Surface; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D004121:Dimethyl Sulfoxide