Cycloheximide treatment of mouse mast cells inhibits serotonin release. Evidence of a requirement for newly synthesized protein in the exocytotic response.
Treatment of mouse peritoneal mast cells and mouse bone marrow-derived cloned mast cells with the protein synthesis inhibitor cycloheximide led to a marked abrogation of serotonin (5-hydroxytryptamine; 5-HT) release induced by a range of activators including antigen, anti-immunoglobulin E (anti-IgE) antibody, calcium ionophore A23187, and the polycation polylysine. Significant inhibition (28%) of IgE-mediated secretion was attained after incubation of peritoneal cells for only 2 hr, and inhibition progressed over a 24 hr period, reaching greater than 80% after 15 hr. When peritoneal mast cells were exposed to cycloheximide and then washed and returned to culture conditions, a substantial recovery of responsiveness to anti-IgE was seen after 5 hr. Under the same conditions to those used in functional studies, cycloheximide inhibited protein synthesis, measured as incorporation of [35S]-methionine, by purified peritoneal mast cells and cloned mast cells to 18.5% and 7.9% of control levels, respectively. These results show that synthesis of new protein over a period of a few hours is required to render mast cells fully responsive to stimuli that act via the IgE receptor, and to certain other stimuli that are receptor-independent.
Buckley
M G
MG
Department of Pharmacology and Therapeutics, University of Liverpool, U.K.
Coleman
J W
JW
D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000001:Calcimycin / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology*; D015536:Down-Regulation; D005089:Exocytosis / Q000187:drug effects; D007073:Immunoglobulin E; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D011107:Polylysine / Q000494:pharmacology; D014176:Protein Biosynthesis; D012701:Serotonin / Q000378:metabolism*
D000888:Antibodies, Anti-Idiotypic; C026408:anti-IgE antibodies; D011107:Polylysine; D012701:Serotonin; D007073:Immunoglobulin E; D000001:Calcimycin; D003513:Cycloheximide