Melatonin suppresses osteoclastic and osteoblastic activities in the scales of goldfish

J Pineal Res. 2002 Nov;33(4):253-8. doi: 10.1034/j.1600-079x.2002.02953.x.


The effects of melatonin on osteoclastic and osteoblastic cells were examined using a culture system of the goldfish scale. Tartrate-resistant acid phosphatase (TRACP) and alkaline phosphatase (ALP) were used as markers of osteoclastic and osteoblastic cells, respectively. In Earle's minimum essential medium containing melatonin (10(-9) to 10(-5) m), activities of both enzymes in scales were significantly suppressed at 6 hr after incubation (TRACP: 10(-8), 10(-6), 10(-5) m; ALP: 10(-7) to 10(-5) m), but at 18 hr only ALP activity was significantly lowered (10(-8), 10(-7) m). Estradiol-17beta (E(2)) enhanced both activities, which were significantly inhibited and brought down to the level of the controls when co-incubated with E(2) and melatonin (TRACP at 6 hr: 10(-9) to 10(-5) m; ALP at 6 hr: 10(-7) m; ALP at 18 hr: 10(-8) m). Moreover, using reverse-transcription polymerase chain reaction, the mRNA expression of the estrogen receptor (ER) and insulin-like growth factor (IGF)-1, which are related to osteoblastic growth and differentiation, was decreased in the melatonin-treated scales. These results suggest that melatonin acts directly on the scale osteoclastic and osteoblastic cells where it suppresses the ALP activity via down-regulation of ER and IGF-1 mRNAs expression. This is the first report on the function of melatonin in osteoclasts and on the suppressive effect of melatonin in osteoblasts among vertebrates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Phosphatase / antagonists & inhibitors
  • Acid Phosphatase / metabolism
  • Alkaline Phosphatase / antagonists & inhibitors
  • Alkaline Phosphatase / metabolism*
  • Animals
  • Cells, Cultured
  • Connective Tissue / drug effects
  • Connective Tissue / metabolism*
  • Estradiol / pharmacology
  • Female
  • Goldfish
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / metabolism
  • Melatonin / pharmacology*
  • Models, Animal
  • Osteoblasts / drug effects*
  • Osteoblasts / metabolism
  • Osteoclasts / drug effects*
  • Osteoclasts / metabolism
  • Tartrate-Resistant Acid Phosphatase


  • Isoenzymes
  • Estradiol
  • Alkaline Phosphatase
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase
  • Melatonin