1 Importance of Amino Acids of the Central Portion of the 2 nd Intracellular Loop of the Gastrin-Releasing Peptide Receptor for Phospholipase C Activation, Internalization and Chronic Down-regulation Michael Schumann, Tomoo Nakagawa, Samuel A. Mantey, Kenji Tokita, David J. Venzon, Simon J. Hocart, Richard V. Benya, and Robert T. Jensen Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (M.S., T.N., S.A.M., K.T., R.V.B., R.T.J.); Biostatistics and Data Management Section, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (D.J.V.); Peptide Research Laboratories, Department of Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana (S.J.H.) Copyright 2003 by the American Society for Pharmacology and Experimental Therapeutics. JPET Fast Forward. Published on September 11, 2003 as DOI:10.1124/jpet.103.055087 This article has not been copyedited and formatted. The final version may differ from this version. JPET Fast Forward. Published on September 11, 2003 as DOI: 10.1124/jpet.103.055087 at ASPET Journals on November 25, 2021 jpet.aspetjournals.org Downloaded from