Short term reductions in cerebral muscarinic receptor concentration of the mouse after in vivo administration of cycloheximide.
[3H]quinuclidinyl benzilate ([3H]QNB) was used to investigate the effects of administration of cycloheximide to mice on the concentration of muscarinic receptors in the cerebral cortex. A single subcutaneous (s.c.) injection of cycloheximide (3.5 mg/kg) reduced receptor concentration by 18% afer an apparent latency of 1 hr. A single intraperitoneal (i.p.) injection of 3.5 mg/kg produced a 14% reduction in muscarinic receptor concentration 20 min after injection. After both s.c. and i.p. administration the effects of cycloheximide were reversible, dose-related and maximal at a dose of 3.5 mg/kg. The maximum reductions in receptor concentrations obtained were 13-18%. Multiple doses of cycloheximide did not produce greater falls in receptor concentration than single doses and did not prevent its return towards control levels. Treatment of mice for 10 day with cycloheximide reduced muscarinic receptor concentration to 71% of the control at 3 days after stopping administration; receptor levels returned to control values 35 days after the last dose of cycloheximide. Treatment of mice with cycloheximide had no effect on the affinity of [3H]QNB for the receptor and, in vitro, 10(-4)M cycloheximide did not have any significant effect on the binding of the radiolabel.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D003513:Cycloheximide / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D008568:Memory / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000187:drug effects; D014316:Tritium
D011976:Receptors, Muscarinic; D014316:Tritium; D011813:Quinuclidinyl Benzilate; D003513:Cycloheximide