Cyclic GMP/metabolism; Gastrointestinal Hormones/metabolism; Intra-Abdominal Fat/metabolism; Macrophages, Peritoneal/metabolism; Natriuretic Peptides/metabolism; Panniculitis, Peritoneal/metabolism; Receptors, Guanylate Cyclase-Coupled/agonists; Receptors, Peptide/agonists; Second Messenger Systems; Animals; Cell Adhesion Molecules/metabolism; Cyclic GMP-Dependent Protein Kinases/metabolism; Diet, High-Fat/adverse effects; Gastrointestinal Hormones/genetics; Immunohistochemistry; Inflammation Mediators/metabolism; Intra-Abdominal Fat/enzymology; Intra-Abdominal Fat/immunology; Intra-Abdominal Fat/pathology; Macrophages, Peritoneal/enzymology; Macrophages, Peritoneal/immunology; Macrophages, Peritoneal/pathology; Male; Microfilament Proteins/metabolism; Natriuretic Peptides/genetics; Obesity/etiology; Obesity/immunology; Obesity/metabolism; Obesity/pathology; Panniculitis, Peritoneal/etiology; Panniculitis, Peritoneal/immunology; Panniculitis, Peritoneal/pathology; Phosphoproteins/metabolism; Phosphorylation; Protein Processing, Post-Translational; Random Allocation; Rats; Rats, Transgenic; Receptors, Enterotoxin; Receptors, Guanylate Cyclase-Coupled/genetics; Receptors, Guanylate Cyclase-Coupled/metabolism; Receptors, Peptide/genetics; Receptors, Peptide/metabolism