Melatonin-induced suppression of the pinealectomy-stimulated rat adrenal cortex mitotic activity.
Pineal involvement in the regulation of adrenocortical mitotic activity has recently been suggested. It has been shown that melatonin (Mel) decreased the mean mitotic activity rate (MMAR) of the adrenal cortex both in vivo and in organ culture. The goal of the present study was to test the influence of pinealectomy (PX) and/or Mel-treatment on the MMAR of adrenocortical cells, as well as on the adrenal weight in rats. The stathmokinetic method was used in the study. It was found that PX significantly increased the MMAR of the adrenocortical cells. Moreover, Mel suppressed the proliferogenic effect of PX on the rat adrenocortical cells. Melatonin alone did not significantly affect the mitotic activity of the adrenal cortex. None of the three experimental procedures, i.e. Mel, PX and Mel-treatment of pinealectomized animals significantly affected the adrenal weight. The present data suggest that Mel may be involved in the inhibitory control of adrenocortical cell proliferation.
Sewerynek
E
E
Department of Experimental Endocrinology and Hormone Diagnostics, Medical Academy of Lódź, Poland.
Lewiński
A
A
Choczaj
V
V
Szkudliński
M
M
Szymczykiewicz
P
P
D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D008550:Melatonin / Q000494:pharmacology*; D008938:Mitosis / Q000187:drug effects* / Q000502:physiology; D008940:Mitotic Index / Q000187:drug effects / Q000502:physiology; D010870:Pineal Gland / Q000502:physiology* / Q000601:surgery; D051381:Rats; D011919:Rats, Inbred Strains
D008550:Melatonin