Desensitization of histamine H1 receptor-mediated cyclic GMP production in guinea-pig lung

Histamine H1 receptor-mediated production of cGMP in guinea-pig lung tissue becomes rapidly desensitized after previous exposure to histamine. This desensitization is clearly concentration dependent and appears to be homologous. Responses to histamine are also inhibited by previous treatment with phorbol 12,13-dibutyrate. Yet, the time course of the inhibition is considerably slower and the maximal inhibition is significantly less compared to receptor desensitization. Moreover, the effects of the phorbol ester are not confined to H1 receptor responses. Since the effects of receptor desensitization are also not prevented by several protein kinase C inhibitors, the development of homologous H1 receptor desensitization is not dependent upon protein kinase C activation, but is caused by a yet unidentified mechanism.