Demonstration of endothelin (ET) receptors on cultured rabbit chondrocytes and stimulation of DNA synthesis and calcium influx by ET-1 via its receptors.
Endothelin (ET) receptors on chondrocytes were demonstrated using cultured rabbit costal chondrocytes. After crosslinking the receptors on the cells with 125I-ET-1, two major bands of 43 kDa and 46 kDa were separated by SDS-PAGE. Scatchard analysis demonstrated two classes of ET receptors with Kd values of 1 x 10(-10) M and 5 x 10(-9) M. The numbers of high- and low-affinity receptors were 1 x 10(4) and 2 x 10(5) per cell, respectively. The binding of ET-1 to chondrocytes was increased by treatment with PTH, DBcAMP, TGF-beta 1, IL-1 beta, RA and EGF. ET-1 stimulated DNA synthesis in cultured rabbit chondrocytes. ET-1 also stimulated calcium incorporation through the cell membrane of chondrocytes. These findings indicate that ET-1 has a physiological effect on chondrocytes via its receptors on the cells.
Kinoshita
A
A
Department of Pedodontics, Osaka University Faculty of Dentistry, Japan.
Tamura
T
T
Aoki
C
C
Nakanishi
T
T
Sobue
S
S
Suzuki
F
F
Takahashi
K
K
Takigawa
M
M
D000818:Animals; D001667:Binding, Competitive; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D016232:Endothelins / Q000378:metabolism / Q000494:pharmacology*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006132:Growth Plate / Q000187:drug effects / Q000378:metabolism*; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010281:Parathyroid Hormone / Q000494:pharmacology; D011817:Rabbits; D017466:Receptors, Endothelin / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
D016232:Endothelins; D007375:Interleukin-1; D010281:Parathyroid Hormone; D017466:Receptors, Endothelin; D016212:Transforming Growth Factor beta; D014212:Tretinoin; D004815:Epidermal Growth Factor; D003994:Bucladesine; D004247:DNA; D002118:Calcium; D013936:Thymidine