Figure 2.

Ligand-binding specificity of GHRH antagonist JV-1–42 binding. Competition for binding of radioligand ¹²⁵I-JV-1–42 to membrane fractions of CAKI-1 human RCC was determined in the presence of increasing concentrations of JV-1–36 (■), JV-1–38 (□), MZ-5–156 (▿), hGHRH(1–44)NH₂ (○), hGHRH(1–29)NH₂ (●), and [His¹,Nle²⁷]hGHRH(1–32)NH₂ (). VIP (♦) as well as glucagon, PACAP, JV-1–53, and PG 97–269 and other unrelated peptides, such as luteinizing hormone-releasing hormone, epidermal growth factor, [Tyr¹¹]somatostatin-14, [Tyr⁴]bombesin, and IGF-I, did not displace the radioligand (data not shown). One hundred percent specific binding is defined as difference between binding in absence and in presence of 10⁻⁵ M JV-1–42. Each data point represents mean of at least two experiments, done in duplicate or triplicate.