title: Circadian-stage dependent ACTH 1-17 effect on DNA synthesis in murine duodenum, colon and rectum.
abstract: The objective was to determine the effect of adrenocorticotropin (ACTH 1-17) on the incorporation of [3H]TdR into DNA (DNA synthesis) in the duodenum, colon and rectum of CD2F1 mice standardised to 12 hr of light alternating with 12 hr of darkness. A question asked was whether the difference in times of administration along the 24-hr time scale influenced any response found. The response was complex as ACTH 1-17 was capable of bringing about statistically significant increases in the incorporation of [3H]TdR into DNA at certain times, decreases at other times, or no response at still another time. A generalization that can be made from all these tissues is that ACTH 1-17 had a greater influence in bringing about a decrease in DNA synthesis when it was administered around the time of transition from dark to light. A similar finding was made earlier for the ACTH 1-17 effect upon the tongue, esophagus and stomach. A 2- and 3-way analysis of variance supports our conclusion that the kind-of-treatment, time-of-treatment and the interval-to-kill (Sampling time) as well as their interactions are important factors when determining any response of ACTH 1-17 or placebo.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002940:Circadian Rhythm; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D004261:DNA Replication / Q000187:drug effects*; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology*; D012007:Rectum / Q000187:drug effects* / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D000324:Adrenocorticotropic Hormone; C028238:ACTH (1-17)