Further insights into the insulin-like growth factor-I system of bony fish pituitary with special emphasis on reproductive phases and social status.
Insulin-like growth factor (IGF)-I, which is crucially involved in fish growth, differentiation, and reproduction, occurs in tilapia pituitary. IGF-I peptide, which is probably produced in hypothalamic perikarya, is present in axons of the neurohypophysis, and IGF-I mRNA and peptide are present in the adenohypophysis in adrenocorticotrophic hormone cells, melanocyte-stimulating hormone cells, with interindividual differences in growth hormone cells, and, starting with puberty, in gonadotrophic hormone (GTH) cells. Subordinate males showed a high IGF-I but a lower beta-luteinizing hormone expression, while in dominant males the opposite was found. IGF-I from the GTH cells may act as auto/paracrine regulators of GTH cell proliferation and enhance GTH synthesis and release during puberty and reproduction, depending on the social status.
Shved
Natallia
N
Division of Neuroendocrinology, Institute of Anatomy, University of Zürich, Zürich, Switzerland.
Baroiller
Jean-François
JF
Eppler
Elisabeth
E
D000818:Animals; D005260:Female; D005399:Fishes / Q000235:genetics*; D005786:Gene Expression Regulation; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology*; D012930:Social Dominance
D007334:Insulin-Like Growth Factor I