Circadian effect of ACTH 1-17 on mitotic index of the corneal epithelium of BALB/C mice.
The objective was to determine the effect of ACTH 1-17, an adrenocorticotropin analogue, on the mitotic index in the corneal epithelium of mice standardized in 12 hr of light alternating with 12 hr darkness. A question asked was whether the time of administration along the 24-hr time scale influenced any response found. The findings showed that ACTH 1-17 could, depending upon when it was administered, bring about a statistically significant decrease, an increase or even no such change in the mitotic index. The greatest responses found were increases, especially when ACTH 1-17 was administered during the dark span. Also the time after injection when the responses occurred varied. The greatest response recorded was at 12 hr after injection when ACTH 1-17 was given at 2 hr into the dark with a 641% and a 718% increase with a low (0.02 IU/kg) and a higher (20 IU/kg) dose, respectively. A 3-way analysis of variance supported the conclusion that the kind-of-treatment, time-of-treatment and treatment-to-kill interval (sampling time) are important factors when determining any response to ACTH 1-17 on the mitotic index.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000502:physiology*; D003624:Darkness; D004848:Epithelium / Q000187:drug effects / Q000502:physiology; D005260:Female; D007700:Kinetics; D008027:Light; D051379:Mice; D008815:Mice, Inbred Strains; D008938:Mitosis / Q000187:drug effects*; D008940:Mitotic Index / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*
D010446:Peptide Fragments; D000324:Adrenocorticotropic Hormone; C028238:ACTH (1-17)