“…However, [Ala 2,8,9,16,19,24,25 ]VIP (analog 8) had high affinity and potency for both VPAC subtypes and was much more metabolically stable than VIP in cells containing each VPAC subtype. These simplified, metabolically stable analogs should be useful for investigating the role of VPAC 1 in biological and pathological processes, for enhanced imaging of tumors overexpressing VIP receptors using VIP receptor scintigraphy (Virgolini, 1997;Thakur et al, 2000Thakur et al, , 2004Rao et al, 2001;Bhargava et al, 2002) as well as for possible VIP receptordirected antitumor treatment for tumors overexpressing VPACs (Gotthardt et al, 2004;Moody et al, 2004;Ou et al, 2005).…”