Shbg distribution in larvae and adult pejerrey tissues. Evidence of an extravascular role.

ANELISA GONZÁLEZ; JUAN I. FERNANDINO; GUSTAVO M. SOMOZA

Buenos Aires

Congreso; XVIII Jornadas Anuales Multidisciplinarias de la Sociedad Argentina de Biología.; 2016

Sociedad Argentina de Biología

Sex hormone-binding globulin (Shbg) is a serum protein that transports sex steroids in the blood of all vertebrates with the exception of birds. It regulates the bioavailability and metabolic clearance of serum steroids. In teleost fish, it is mainly expressed in the liver but Shbg protein distribution is wider. In this study we evaluated the tissue distribution of Shbg by inmunohistochemistry in pejerrey larvae at 8 weeks post-hatching and in adult tissues. In larvae Shbg immunoreactivity (ir-Shbg) was detected in the hepatopancreas, intestine, gills, particularly in red blood cells on central blood capillary of primary lamella, pseudobranch and taste bud cells located at the epidermis. In adults ir-Shbg was detected in the hepatopancreas, primarily in the pancreas, gills (mainly concentrated in endothelial and interlamelar cells but not in red blood cells) and intestine. ir-Shbg was also found in the gonads. In the ovary we found stronger ir-Shbg inside the oocyte, like dispersed drops, within the cortical alveoli as well as on corionic filaments. In testes the main ir-Shbg was present surrounding the seminiferous lobules. Although the biological significance of these findings remain to be determined, the distribution of Shbg in pejerrey tissues, in taste buds and red blood cells in larvae and within the oocyte in adult females, provide evidence that Shbg has functions in extravascular compartments, extending its function beyond a carrier protein.