West China Journal of Stomatology

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An Experimental Study on Circadian Rhythm of the Proliferative Index of Mandibular Osteoblast in Goats

ZHENGXiaohui,TIANWeidong,LONGJie,et al.   

  1. Department ofOral andMaxillofacialSurgery,West China College ofStomatol- ogy,Sichuan University,Chengdu610041,China
  • Received:2003-02-25 Revised:2003-02-25 Online:2003-02-20 Published:2003-02-20

Abstract:

Objective The aim of this study was to investigate the circadian rhythm of the proliferative index of mandibular osteoblasts of goats in a normal situation.Methods Twenty four healthy goats were selected and randomly divided into six groups. They were killed, and a piece of bone tissue with 2 cm×2 cm×0.5 cmwas obtained from rightmandibularmental foramen region at 0∶00, 4∶00, 8∶00, 12∶00, 16∶00 and 20∶00 time points, after they had been fed for one week. The primary cell culture method was used to cultivate osteoblasts from the bone. The method of anti-5-bromodeoxyuridine monoclonal antibody and the flow cytometric analysis were used to detect the proliferative index of the mandibular osteoblasts at different time. The data were analyzed using the method of single cosine rhythmometry.Results The proliferative indexes of the mandibular osteoblasts of goats were higher at the nighttime and lower in the daytime. The undulation of the proliferative indexes displayed a significant circadian rhythm (P<0.01). The peak value was obtained at about 19∶44, and the lowest value at about 7∶44.Conclusion The proliferative indexes of the man- dibular osteoblasts of goats are not stablewithin 24 hours in a normal situation, butwith significant circadian rhythm. There are differ- ent proliferative indexes at different time points.

Key words: osteoblast, proliferative, circadian rhythm, flow cytometry