Expression of gonadotrophin-releasing hormone binding sites in somatic tissues of the gilthead seabream (Sparus aurata): a quantitative autoradiographic study

D. González-Martínez¹, C. Sarasquete², E. Pascual² and J.A. Muñoz-Cueto<sup>1

1</sup>Department of Biology, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real, Cadiz, Spain and ²Institute of Marine Sciences of Andalucia, CSIC, Puerto Real, Cadiz, Spain

Offprint requests to: Dr. José Antonio Muñoz-Cueto, Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro, 11510 Cádiz, Spain. e-mail: munoz.cueto@uca.es


Summary. In this study, we have analysed the expression of gonadotrophin-releasing hormone (GnRH) binding sites in somatic tissues (intestine, liver, gill, skeletal muscle, ovary, heart, stomach, kidney and spleen) of the gilthead seabream, Sparus aurata using 3-[¹²⁵I]iodototyrosyl⁵-mammalian GnRH and auto-radiographic techniques. The qualitative and quantitative analysis showed the existence of a basal expression of specific GnRH binding sites in intestine, skeletal muscle, ovary, stomach and spleen. Furthermore, our data suggest that the level of expression of GnRH binding sites can be significantly enhanced by GnRH treatment in intestine, gill, heart, stomach, kidney and spleen. This study shows that GnRH can exert direct effects in both reproductive and non-reproductive somatic tissues of the gilthead seabream. Histol Histopathol 21, 1065-1073 (2006)

Key words: GnRH binding sites, Hormonal induction, Somatic tissues, Perciform, Autoradiography

DOI: 10.14670/HH-21.1065