Effects of tank color on melanin-concentrating hormone levels in the brain, pituitary gland, and plasma of the barfin flounder as revealed by a newly developed time-resolved fluoroimmunoassay.
A pleuronectiform fish, the barfin flounder Verasper moseri, reared in a white tank had a smaller ratio of pigmented area of the skin on non-eyed side, grew faster, and had greater melanin-concentrating hormone (MCH)-immunoreactive cell bodies and MCH gene expression in the brain than in the black tank, indicating that synthesis and release of MCH are higher in fish from a white tank. In the present study, a time-resolved fluoroimmunoassay for MCH was developed. MCH levels were assessed in the brain, pituitary gland, and plasma of barfin flounders reared in a white or black tank. A competitive assay using two antibodies was performed among secondary antibodies in the solid phase, MCH antibodies, samples, and europium-labeled MCH. Displacement curves of serially diluted extracts (brain, pituitary gland, and plasma) of the barfin flounder paralleled that of the MCH standard. MCH levels in the brain and plasma were higher in fish reared in the white tank for 5 months than in the black tank. These results suggest that synthesis and secretion of MCH are enhanced with the white background and that MCH is involved in both somatic growth and the skin pigmentation in the barfin flounder.
School of Fisheries Sciences, Kitasato University, Ofunato, Iwate 022-0101, Japan.
Noriko
N
Amiya
Masafumi
M
Amano
Akiyoshi
A
Takahashi
Takeshi
T
Yamanome
Hiroshi
H
Kawauchi
Kunio
K
Yamamori
D000222:Adaptation, Physiological; D000818:Animals; D001923:Brain Chemistry; D003116:Color; D005432:Flounder / Q000254:growth & development / Q000502:physiology*; D015200:Fluoroimmunoassay; D006799:Housing, Animal; D007028:Hypothalamic Hormones / Q000097:blood*; D008543:Melanins / Q000097:blood*; D010902:Pituitary Gland / Q000737:chemistry; D010907:Pituitary Hormones / Q000097:blood*; D012880:Skin Pigmentation / Q000502:physiology*
D007028:Hypothalamic Hormones; D008543:Melanins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone