Complementary localization of VIP receptors and SS receptors in a human lymph node. (A) CD3 immunohistochemical staining. Bar = 1 mm. (B) Autoradiogram showing total binding of¹²⁵I-VIP. VIP receptors are in the whole lymph node with exception of the germinal centers. (C) Autoradiogram showing total binding of ¹²⁵I-Tyr³-octreotide. SS receptors are predominantly located in germinal centers.