[Hyp3]-bradykinin and [Hyp3]-Lys-bradykinin interact with B2-bradykinin receptors and stimulate inositol phosphate production in cultured human fibroblasts.

R Dengler, A Faussner, W Müller-Esterl, A A Roscher

Index: FEBS Lett. 262 , 111-114, (1990)

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Abstract

The recently isolated, naturally occurring peptide hormones [Hyp3]-bradykinin and [Hyp3]-Lys-bradykinin were investigated for their agonist activity on solubilized binding sites from human fibroblasts. Both ligands competed with [3H]bradykinin binding in a dose-dependent fashion with potencies similar to bradykinin (BK) and Lys-BK. Biological activity was assessed by determination of inositol phosphate accumulation and cyclic 3',5'-adenosine monophosphate synthesis in intact cultured cells. Stimulation by the hydroxylated peptides resulted in a pronounced accumulation of both parameters with similar effectiveness as BK and Lys-BK. These results indicate that [Hyp3]-BK and [Hyp3]-Lys-BK are agonists at the bradykinin receptor system with properties comparable to their non-hydroxylated analogues. This suggests that hydroxylation of kinins does not alter receptor interaction or signal transduction in cultured human fibroblasts.