Expression und zelluläre Lokalisation von Guanylin, Uroguanylin und Proteinen der Signaltransduktionskette in der Niere der Ratte

Guanylin and uroguanylin are peptide hormons that activate CFTR-chloride channels via cGMP increase after activation of their specific receptor guanylyl cyclase type c. This mechanism was formerly described in many organ systems, whereas the intestinal tract seemed to be the major target of this guanylin/uroguanylin induced regulation of elektrolyte transport. The finding of uroguanylin in the urine and positive expression of guanylyl cyclase type c in the kidney leads to an hypothesis of the existence of an natriuretic intestinal peptide, that links the digestive system with the kidney in an hormonal way. In which extend the kidney directly could be involved in a novel guanylin/uroguanylin induced regulation mechanism was unclear. Our investigation focused on rat kidney, the main organ of water and electrolyte regulation. Our findings could determine the regional expression, protein synthesis and cell-specific localisation of guanylin, uroguanylin and the proteins of their signalling pathway in rat kidney.