This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Iigo, M. Articles by Aida, K. Search for Related Content PubMed PubMed Citation Articles by Iigo, M. Articles by Aida, K. Social Bookmarking                         What's this?

Ocular Melatonin Rhythms in the Goldfish, Carassius auratus

Department of Anatomy, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki 216, Japan

Kiyoshi Furukawa

Laboratory of Aquatic Animal Physiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo, Tokyo 113, Japan

Atsuhiko Hattori

Department of Anatomy, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki 216, Japan

Ritsuko Ohtani-Kaneko

Department of Anatomy, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki 216, Japan

Masayuki Hara

Department of Anatomy, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki 216, Japan

Takuro Suzuki

Department of Anatomy, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki 216, Japan

Mitsuo Tabata

Department of Biosciences, Teikyo University of Science and Technology, Uenohara, Yamanashi 409-01, Japan

Katsumi Aida

Laboratory of Aquatic Animal Physiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo, Tokyo 113, Japan

Ocular melatonin rhythms in the goldfish were studied and compared to those in the pineal organ and plasma. Under light:dark (LD) of 12 h light:12 h dark, melatonin contents in the eye as well as the pineal organ and plasma exhibited clear day-night changes with higher levels at mid-dark than at mid-light. However, melatonin contents in the eye at mid-light and mid-dark were approximately 100 and 9 times greater than those in the pineal organ, respectively. Day-night changes of ocular melatonin persisted after pinealectomy, which abolished those in plasma melatonin under LD 12:12. Ocular melatonin contents in the pinealectomized fish at mid-light were significantly higher than those in the sham-operated control. Under constant darkness (DD), circadian melatonin rhythms were observed in the eye but damped on the 3rd day, whereas plasma melatonin rhythms generated by the pineal organ persisted for at least 3 days. Under constant light, ocular melatonin contents exhibited a significant fluctuation with a smaller amplitude than that under DD, whereas plasma melatonin remained at low levels. These results indicate the involvement of LD cycles, a circadian clock, and the pineal organ in the regulation of ocular melatonin rhythms in the goldfish.

Key Words: circadian rhythms • melatonin • eye • pineal organ • plasma • pinealectomy • goldfish • teleost

Journal of Biological Rhythms, Vol. 12, No. 2, 182-192 (1997)
DOI: 10.1177/074873049701200209


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				Md. S. Rahman, B.-H. Kim, A. Takemura, C.-B. Park, and Y.-D. Lee Effects of Moonlight Exposure on Plasma Melatonin Rhythms in the Seagrass Rabbitfish, Siganus Canaliculatus J Biol Rhythms, August 1, 2004; 19(4): 325 - 334. [Abstract] [PDF]

				C. Ribelayga, Y. Wang, and S. C. Mangel A circadian clock in the fish retina regulates dopamine release via activation of melatonin receptors J. Physiol., January 15, 2004; 554(2): 467 - 482. [Abstract] [Full Text] [PDF]