gastrins and Metabolic-Diseases

Obesity and its comorbidities, such as type 2 diabetes mellitus and cardiovascular disease, constitute growing challenges for public health and economies globally. The available treatment options for these metabolic disorders cannot reverse the disease in most individuals and have not substantially reduced disease prevalence, which underscores the unmet need for more efficacious interventions. Neurobiological resilience to energy homeostatic perturbations, combined with the heterogeneous pathophysiology of human metabolic disorders, has limited the sustainability and efficacy of current pharmacological options. Emerging insights into the molecular origins of eating behaviour, energy expenditure, dyslipidaemia and insulin resistance suggest that coordinated targeting of multiple signalling pathways is probably necessary for sizeable improvements to reverse the progression of these diseases. Accordingly, a broad set of combinatorial approaches targeting feeding circuits, energy expenditure and glucose metabolism in concert are currently being explored and developed. Notably, several classes of peptide-based multi-agonists and peptide-small molecule conjugates with superior preclinical efficacy have emerged and are currently undergoing clinical evaluation. Here, we summarize advances over the past decade in combination pharmacotherapy for the management of obesity and type 2 diabetes mellitus, exclusively focusing on large-molecule formats (notably enteroendocrine peptides and proteins) and discuss the associated therapeutic opportunities and challenges.

Topics: Animals; Body Mass Index; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Female; Gastrins; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Male; Metabolic Diseases; Metformin; Mice; Molecular Targeted Therapy; Obesity; Prognosis; Risk Assessment; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome

In this paper, the established and possible roles of CCK1 and CCK2 receptors in gastrointestinal (GI) and metabolic diseases are reviewed and available results from human agonist/antagonist studies are discussed. While there is evidence for the involvement of CCK1R in numerous diseases including pancreatic disorders, motility disorders, tumor growth, regulation of satiety and a number of CCK-deficient states, the role of CCK1R in these conditions is not clearly defined. There are encouraging data from several clinical studies of CCK1R antagonists in some of these conditions, but their role as therapeutic agents remains unclear. The role of CCK2R in physiological (atrophic gastritis, pernicious anemia) and pathological (Zollinger-Ellison syndrome) hypergastrinemic states, its effects on the gastric mucosa (ECL cell hyperplasia, carcinoids, parietal cell mass) and its role in acid-peptic disorders are clearly defined. Furthermore, recent studies point to a possible role for CCK2R in a number of GI malignancies. Current data from human studies of CCK2R antagonists are presented and their potential role in the treatment of these conditions reviewed. Furthermore, the role of CCK2 receptors as targets for medical imaging is discussed.

Topics: Animals; Cholecystokinin; Gastrins; Gastrointestinal Diseases; Humans; Metabolic Diseases; Receptors, Cholecystokinin

With combined immunofluorescent, cytochemical and electron microscopic investigations the enterochromaffin cell system has been differentiated into 5 distinct endocrine cell types in the human stomach and into 8 cell types in the intestine. These endocrine cells are probably of neuroectodermal origin and belong to the APUD (amine precursor uptake and decarboxylation)-system. Maximal gastrointestinal hormone concentrations as determined by tissue extracts correlate fairly well to the location of each endocrine cell type in various segments of the gastrointestinal tract. In certain gastroenteropathies the pathophysiological disturbances can be explained by pathomorphological alterations of the disseminated endocrine cells. 1. The gastrin-producing G-cell is the predominating endocrine cell in the gastric antrum. Besides immunocytochemistry the G-cell can be demonstrated with argyrophilic reaction (Grimelius, 1968), masked metachromasia and leadhematoxylin. The ultrastructural features are variable, depending on functional activity. The secretory granules are usually only slightly osmiophilic, measuring 200 till 250 nm in diameter. By some working groups a positive immunofluorescence with gastrin-antisera has been demonstrated in A1- or D-cells of the pancreatic islets. However, numerous negative results have been reported, too. Considering physiological conditions, a gastrin-secretion of the human pancreatic islets has not been secured without doubt. 2. The EC-cell produces serotonin and in the intestine motilin, too. Besides the formaldehyde-induced fluorescence, these cells can be demonstrated with diazonium and argentaffin reactions, less specific with argyrophilic methods. Ultrastructurally the EC-granules are easily differeniated from the other endocrine cells by their pronounced osmiophilia and pleomorphism. In experimental conditions the EC-cells demonstrate species- and site-specific alterations. With reserpine no ultrastructural changes were demonstrable in EC-cells of the rat. However, marked ultrastructural alterations with an increase of the hormone-producing organelle system were noticed after administration of parachlorophenylalanine (PCPA) which interferes with serotonine synthesis; 5. The gastric D-cells are characterized by large secretory granules similar to pancreatic D-cells. They secrete the HCl-inhibitory peptide somatostatin. 4. The D1-cell is a cell type with unknown function. The cytoplasm contains small granules with variable elect

Topics: Adenoma, Islet Cell; Anemia, Pernicious; Chromaffin System; Digestive System; Duodenal Ulcer; Endocrine System Diseases; Enterochromaffin Cells; Esophagitis, Peptic; Gastrectomy; Gastric Mucosa; Gastrins; Gastritis; Gastrointestinal Hormones; Gastrointestinal Neoplasms; Humans; Intestinal Mucosa; Metabolic Diseases; Serotonin; Somatostatin; Stomach Neoplasms; Stomach Ulcer; Syndrome; Zollinger-Ellison Syndrome

Topics: Amino Acid Sequence; Digestive System Physiological Phenomena; Gastric Inhibitory Polypeptide; Gastrins; Gastrointestinal Hormones; Gastrointestinal Neoplasms; Glucagon; Humans; Metabolic Diseases; Molecular Conformation; Motilin; Radioimmunoassay; Secretin; Vasoactive Intestinal Peptide

Topics: Animals; Dogs; Gastric Juice; Gastrins; Hyperplasia; Metabolic Diseases; Molecular Weight; Pyloric Antrum; Radioimmunoassay; Secretin

Topics: Adrenal Gland Diseases; Endocrine System Diseases; Erythrocytes; Female; Gastrins; Gynecomastia; Hormones, Ectopic; Humans; Hypercalcemia; Hyperplasia; Hyperthyroidism; Hypoglycemia; Male; Malignant Carcinoid Syndrome; Metabolic Diseases; Neoplasms; Neurologic Manifestations; Polycythemia; Prognosis; Puberty, Precocious; Vasopressins