Bilateral lesions of suprachiasmatic nuclei affect circadian rhythms in (/sup 3/H)-thymidine incorporation into deoxyribonucleic acid in mouse intestinal tract, mitotic index of corneal epithelium, and serum corticosterone

Journal Article · Tue Mar 01 00:00:00 EST 1983 · Anat. Rec.; (United States)

DOI:https://doi.org/10.1002/ar.1092050302· OSTI ID:5776767

Scheving, L E; Tsai, T H; Powell, E W; Pasley, J N; Halberg, F; Dunn, J

Investigations into the role of the suprachiasmatic nuclei (SCN) in the coordination of circadian rhythms have presented differing results. Several reports have shown that ablation of the suprachiasmatic nuclei (SCNA) alters the phase and amplitude of rhythms but does not abolish them. The present study investigates the effect of SCNA on the rhythms in cell proliferation in various regions of the intestinal tract as measured by the incorporation of (/sup 3/H)-thymidine into deoxyribonucleic acid, in the mitotic activity of the corneal epithelium, and in serum corticosterone levels. The study involved mice with verified lesions of the SCN (six to 13 mice per time point) and control groups of both sham-operated and unoperated mice (seven of each per time point). The mice were killed in groups that represented seven time points over a single 24 hr span (3 hr intervals with the 0800 hr sampled both at start and end of the series). The tissues examined were the tongue, esophagus, gastric stomach, and colon for DNA synthesis, the corneal epithelium for mitotic index, and blood serum for corticosterone level. The most consistent result of SCNA was a phase advance in the rhythms in cell proliferation in the tongue, esophagus, gastric stomach, colon, and corneal epithelium. A reduction in rhythm amplitude occurred in the tongue, esophagus, and corneal epithelium; however, there was an amplitude increase for the stomach, colon, and serum corticosterone. The mesor (rhythm-adjusted mean) was increased by SCNA in all tissues except the corneal epithelium. These findings further support the role of the suprachiasmatic nuclear area in the control of rhythms in cell proliferation and corticosterone production, by acting as a ''phase-resetter'' and as a modulator of rhythm amplitude.

• Research Organization: Department of Anatomy, College of Medicine, University of Arkansas for Medical Sciences, Little Rock
• OSTI ID: 5776767
• Journal Information: Anat. Rec.; (United States), Vol. 205:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DAILY VARIATIONS
BIOCHEMISTRY
TRITIUM COMPOUNDS
TRACER TECHNIQUES
BIOLOGICAL FUNCTIONS
CELL NUCLEI
CELL PROLIFERATION
CHROMOSOMAL ABERRATIONS
DNA
MICE
THYMIDINE
UPTAKE
ANIMALS
AZINES
CELL CONSTITUENTS
CHEMISTRY
FUNCTIONS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MUTATIONS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RIBOSIDES
RODENTS
VARIATIONS
VERTEBRATES
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