Prolactin inhibits osteoclastic activity in the goldfish scale: a novel direct action of prolactin in teleosts.
In teleosts, prolactin is involved in calcium regulation, but its role in scale/bone metabolism is unclear. Using the in-vitro system with goldfish scales developed recently, we explored the effects of teleost prolactin, growth hormone, and somatolactin on osteoclasts and osteoblasts. Addition of prolactin at concentrations of 0.01-100 ng/ml reduced osteoclastic activity, partly via osteoclast apoptosis, after 6-18 h incubation. Conversely, growth hormone and somatolactin at a concentration of 100 ng/ml increased osteoclastic activity after 18 h incubation, indicating the specificity of the inhibitory effect of prolactin on osteoclastic activity. On the other hand, these three hormones promoted osteoblastic activity at concentrations of 10-100 ng/ml. The results from this study are the first demonstration of direct effects of prolactin on scale/bone metabolism and osteoclastic activity in a teleost.
Takahashi
Hideya
H
Ushimado Marine Laboratory, Graduate School of Natural Science and Technology, Okayama University, Setouchi, Okayama, Japan.
Suzuki
Nobuo
N
Takagi
Chiyo
C
Ikegame
Mika
M
Yamamoto
Toshio
T
Takahashi
Akiyoshi
A
Moriyama
Shunsuke
S
Hattori
Atsuhiko
A
Sakamoto
Tatsuya
T
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D005260:Female; D029941:Fish Proteins / Q000494:pharmacology; D006023:Glycoproteins / Q000494:pharmacology; D006054:Goldfish / Q000502:physiology*; D013006:Growth Hormone / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects; D010010:Osteoclasts / Q000187:drug effects*; D010907:Pituitary Hormones / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology*; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors
D029941:Fish Proteins; D006023:Glycoproteins; D007527:Isoenzymes; D010907:Pituitary Hormones; C064448:somatolactin protein, fish; D011388:Prolactin; D013006:Growth Hormone; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase