Effects of leptin to cultured growth plate chondrocytes.
OBJECTIVE
This study aimed to evaluate whether leptin has any effect on growth plate chondrocytes.


METHODS
We studied the effects of exogenous leptin on cultured rabbit growth plate chondrocytes. This involved assessing [3H]thymidine incorporation, alkaline phosphatase (ALP) activity, proteoglycan production, leptin receptor (Ob-R) activity, and detection of Ob-R using Western blot analysis.


RESULTS
The existence of Ob-R in growth plate chondrocytes was revealed by Western blot and Ob-R activity. Prior to semiconfluence, leptin increased [3H]thymidine incorporation while at the semiconfluent and early confluent stages, leptin promoted ALP activity and tended to promote proteoglycan production.


CONCLUSIONS
Growth plate chondrocytes possess Ob-Rs, and leptin enhance chondrocyte proliferation and subsequent cell differentiation.
Nakajima
Ryoichi
R
Department of Pediatrics, Osaka City University Graduate School of Medicine, Osaka, Japan. ryoichi@msic.med.osaka-cu.ac.jp
Inada
Hiroshi
H
Koike
Tatsuya
T
Yamano
Tsunekazu
T
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism*; D006132:Growth Plate; D020738:Leptin / Q000008:administration & dosage / Q000009:adverse effects*; D009765:Obesity / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism; D054411:Receptors, Leptin; D013936:Thymidine / Q000378:metabolism
D020738:Leptin; D011509:Proteoglycans; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D000469:Alkaline Phosphatase; D013936:Thymidine