Inhaltsangabe1 Localization and Colocalization of Gastrointestinal Peptides.- A. Introduction.- B. Coexistence of Messengers.- C. Endocrine and Paracrine Cells.- I. Stomach.- II. Small Intestine.- III. Large Intestine.- IV. Coexistence of Peptides in Gut Endocrine Cells.- D. Enteric Neurons.- I. Distribution of Peptide-Containing Nerve Fibers in the Digestive Tract.- II. Projections of Enteric Neurons in the Rat.- 1. Myenteric Neurons.- 2. Submucous Neurons.- III. Coexistence of Peptides in Enteric Neurons.- References.- 2 Regulation of Gastrointestinal Peptide Hormone Gene Expression.- A. Introduction.- B. Gene Structure.- C. RNA Polymerase II.- D. Transcriptional Regulation Overview.- I. DNA Elements.- II. Transcription Factors.- 1. General Transcription Factors.- 2. Regulated Transcription Factors.- 3. Modulation of Transcription Factor Activity.- III. Transcriptional Repression.- IV. Genes Lacking TATA Elements.- E. Analysis of Gene Expression.- I. RNA Quantitation.- II. Promoter Studies.- F. Regulation of Specific Hormone Gene Expression.- I. Preface.- II. Gastrin/Cholecystokinin Family.- 1. Gastrin: Background.- 2. Luminal Regulation of Gastrin Gene Expression.- 3. Islet Cell Gastrin Expression.- 4. Gastrin Promoter Analysis.- a) Studies in Pituitary Cell Lines.- b) Studies in Islet Cells.- 5. Cholecystokinin: Background.- 6. Cholecystokinin Gene Regulation: RNA Quantitation.- 7. Cholecystokinin: Promoter Analysis.- III. Somatostatin.- 1. Somatostatin Gene Regulation.- 2. Model of cAMP Regulation.- 3. Tissue Specific Expression.- IV. Glucagon.- V. Secretin.- VI. Motilin.- G. Conclusion.- References.- 3 Post-Translational Processing of Regulatory Peptides.- A. Introduction.- B. General Design of Processing Systems.- I. Active Peptide Stored in Secretory Vesicles.- II. Active Peptide Released Constitutively.- III. Precursor Activated in or Near Cell of Origin.- 1. Precursor Stored Intracellularly.- 2. Precursor Anchored to Cell Surface.- IV. Precursor Activated in the Interstitial Space or Blood.- V. Precursor Activated at Target or by Other Cells.- 1. Precursor Stored Outside Target.- 2. Precursor Stored Inside Target.- VI. Mixed Systems.- C. Intracellular Trafficking and Processing Pathways.- D. Processing Sites and General Mechanisms.- I. Two-Step Processing.- II. Dibasic, Monobasic and Nonbasic Sites.- III. Conformation and Consensus Features.- IV. Sequentially Ordered Reactions.- V. Tissue-Specific Processing.- E. Enzymes Involved in the Processing of Prohormones.- I. Dibasic Residue-Specific Endoproteases.- II. Monobasic Residue-Specific Endoproteases.- III. Tetrabasic Residue-Specific Endoproteases.- IV. Exopeptidases.- V. Enzymes Involved in N- and C-Terminal Modification.- 1. Acetyltransferase.- 2. Glutaminyl Cyclase.- 3. Peptidylglycine a-Amidating Monooxygenase.- VI. Enzymes Involved in Sulfation and Phosphorylation.- 1. Tyrosine Sulfation Enzyme.- 2. Serine Phosphorylating Enzymes.- F. Processing of Specific Prohormones.- I. Yeast Pheromones.- II. Proopiomelanocortin.- III. Gastrointestinal Hormones.- 1. Glucagon and Related Peptides.- 2. Cholecystokinin.- 3. Gastrin.- 4. Somatostatin.- 5. Neurotensin and Neuromedin-N.- 6. Pancreatic Polypeptide.- G. Conclusion.- References.- 4 Regulation of Peptide Secretion from Gastroenteric Endocrine Cells.- A. Introduction.- B. Gastroenteric Endocrine Cells.- I. Localization.- II. Methods for Studying Peptide Release.- C. Neurotransmitter and Peptide Regulation of Release.- I. Acetylcholine.- II. Norepinephrine.- III. Somatostatin.- IV. Gastrin-Releasing Peptide and Bombesin.- V. Gastrin and Cholecystokinin.- D. Nutrient Regulation of Peptide Release.- I. Proteins and Amino Acids.- II. Fatty Acids.- E. Regulation of Release by Luminal pH.- F. Summary.- References.- 5 Peptide Receptors and Signal Transduction in the Digestive Tract.- A. Introduction.- B. General Considerations and Methodology.- I. Receptor Concept and General Properties.- II. Methods for Study of Receptors.- 1. Tissue P