Vapreotide attenuates the Substance P (SP)-triggered intracellular calcium increases and NF-κB activation in a dose-dependent manner. Vapreotide also inhibits SP-induced IL-8 and MCP-1 production in HEK293-NK1R and U373MG cell lines. Vapreotide inhibits HIV-1 infection of human MDM in vitro, an effect that is reversible by SP pretreatment. Vapreotide significantly inhibits GH-, PRL, and/or alpha-subunit release by human GH-secreting pituitary adenoma cells in concentrations as low as 10-10 M. Vapreotide inhibits GH release with an IC50 of 0.1 pM. Vapreotide exhibits moderate-to-high affinities for SSTR2, -3, and -5 (IC50=0.17, 0.1 and 21 nM, respectively) and low affinity for SSTR1 and -4 (IC50=200 and 620 nM, respectively). RC-160 inhibits serum-induced proliferation of CHO cells expressing SSTR2 and SSTR5 (EC50=53 and 150 pM, respectively).