Rol de MCH en el crecimiento somático en el pez cíclido Cichlasoma dimerus

PEREZ SIRKIN, DANIELA; CÁNEPA, MAXIMILIANO; FOSSATI, MARIANA; VISSIO, PAULA

IByME, Ciudad Autónoma de Buenos Aires 2-4 diciembre .

Jornada; XI JORNADAS ANUALES DE LA SOCIEDAD ARGENTINA DE BIOLOGÍA.; 2009

Sociedad Argentina de Biología

Fish growth is regulated by different environmental factors and this process is stimulated by growth hormone (GH), whose neuroendocrine regulation is multifactorial. Melanin concentrating hormone (MCH) is a hypothalamic hormone that innervates the adenohypophisis and, together with other hormones, participates in the endocrine control of body colour in fish. In C. dimerus, like in mammals, MCH could be involved in food intake. In human it has been observed that MCH may regulate pituitary GH secretion. The aim of this work was to analyze if MCH acts on the GH secretion in C. dimerus. The experimental approach was performed at different levels: 1) double label immunohistochemistry (IHC) to MCH and GH, 2) analysis of GH release in pituitary cultures stimulated with MCH, and 3) quantification of somatic growth in fish maintained in white or black background (high or low MCH levels). By double label IHC we observed MCH fibers in close contact with GH cells in the ADH. Also we observed that MCH stimulates GH secretion. Finally we observed an increase in somatic growth in fish mantained in white background. These results suggest that MCH participes in GH secretion in C. dimerus and therefore, somatic growth is affected by background colour.