Circadian variation of the cell proliferation in the jejunal epithelium of rats at weaning phase.
Circadian variation in cell proliferation of the jejunal epithelium of 18-day-old rats was studied using the 2-h arrested metaphase score and crypt isolation method. A continuous decrease in the arrested metaphases occurred from 07.00 h to 13.00 h. From 17.00 h arrested metaphase values increased and were maintained at the higher level during the dark period as showed by Cosinor analyses (P < 0.05). These results indicate that in the young rat there is already a circadian variation in jejunal epithelial cell proliferation as early as 18 days. We can even suggest that the presence of a circadian rhythm at weaning contributes to the steady state of cell proliferation in the intestinal epithelium observed in adult life.
Departamento de Biologia Estrutural, Molecular e Genética. Setor de Ciências Biológicas e da Saúde, Universidade Estadual de Ponta Grossa, Paraná, Brazil. osteoblasto@ig.com.br
J R
JR
Gomes
A A M
AA
Pereira
L
L
Barth
J S
JS
Silva
M L
ML
Leite
A C M
AC
Wille
M A M
MA
Soares
D000818:Animals; D000833:Animals, Suckling; D002455:Cell Division / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D007413:Intestinal Mucosa / Q000166:cytology*; D007583:Jejunum / Q000166:cytology*; D008297:Male; D008677:Metaphase / Q000502:physiology; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar; D014886:Weaning