title: Synthetic adrenocorticotropin for optimizing murine circadian chronotolerance for adriamycin.
abstract: An attempt to pre-set the circadian rhythm in murine chronotolerance for adriamycin (ADR) given i.p. or i.v. with ACTH was performed in three studies. In CDF1 mice standardized in LD12:12, it was demonstrated that 1) the circadian rhythm in murine chronotolerance for ADR exhibits a different timing depending upon whether the intravenous or intraperitoneal route is used for the administration of this anticancer agent; 2) ACTH or saline pretreatment does not enhance optimal circadian-stage-qualified ADR tolerance, whatever its route of injection, with any of the circadian stages and schedules explored; 3) near-optimal tolerance can be achieved by a fixed 'best' interval (among those investigated) between ACTH and ADR, irrespective of circadian stage. Tolerance equivalent to optimal circadian-stage-qualified ADR tolerance results from the administration of ACTH 1-17 (HOE433 = Synchrodyn) 24 hours before ADR injection; 4) and acrophase advance of over 6 hours of the tolerance rhythm results from ACTH 1-17 administration at 6 HALO. The acrophase changes do not directly account for an optimal ADR tolerance at a fixed interval of 24 hours after ACTH 1-17. Thus, ACTH may be considered a potential relative chronizer of murine chronotolerance for ADR.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D004317:Doxorubicin / Q000633:toxicity*; D004361:Drug Tolerance; D005260:Female; D008297:Male; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology*; D012737:Sex Factors
chemical_list: D010446:Peptide Fragments; C012854:acethropan-S; D004317:Doxorubicin; D000324:Adrenocorticotropic Hormone