The ability [DTyr6, βAla11,Phe13,Nle14]Bn(6-14) (Peptide # 1) and the putative BRS-3 selective agonist peptide #16a, to stimulate activation of growth of hBRS-3/Balb cells. hBRS-3/Balb cells were incubated with the indicated concentration of [DTyr6, βAla11,Phe13,Nle14]Bn(6-14) (Peptide # 1) or peptide #16a and the affect on [3H]thymidine incorporation determined as described in Methods. Results are means ± SEM from four experiments and are expressed as the percentage of the increase caused by 1 μM [DTyr6, βAla11,Phe13,Nle14]Bn(6-14) (Peptide # 1). Mean control and 1 μM [DTyr6, βAla11,Phe13, Nle14]Bn(6-14)-stimulated values hBRS-3/Balb cells were 2371 ± 92 and 3244 ± 62 cpm, respectively.