Diet modification and its influence on metabolic and related pathological alterations in the SHR/NDmcr-cp rat, an animal model of the metabolic syndrome

• Published in: Experimental and toxicologic pathology : official journal of the Gesellschaft für Toxikologische Pathologie Vol. 64; no. 4; pp. 333 - 338
• Main Authors: Kawai, Kouji, Sakairi, Tetsuya, Harada, Shuichi, Shinozuka, Junko, Ide, Mika, Sato, Hiroko, Tanaka, Masaharu, Toriumi, Wataru, Kume, Eisuke
• Format: Journal Article
• Language: English
• Published: Munich Elsevier GmbH 01.05.2012; Elsevier
• Subjects: animal models; Animals; Biological and medical sciences; Blood Glucose; Blood Pressure - physiology; Body Weight - physiology; Diabetes. Impaired glucose tolerance; Diabetogenic diet; Diet; Disease Models, Animal; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; excretion; fatty liver; Fatty Liver - metabolism; Fatty Liver - pathology; genes; glucose; Glycated Hemoglobin A - analysis; Glycosuria; high fat diet; histopathology; Hyperglycemia - diet therapy; Hyperglycemia - metabolism; Hyperglycemia - pathology; hyperlipidemia; Hyperlipidemias - diet therapy; Hyperlipidemias - metabolism; Hyperlipidemias - pathology; hyperplasia; Hyperplasia - metabolism; Hyperplasia - pathology; hypertension; Hypertension - diet therapy; Hypertension - metabolism; Hypertension - pathology; insulin secretion; Investigative techniques, diagnostic techniques (general aspects); Islet hyperplasia; Islets of Langerhans - metabolism; Islets of Langerhans - pathology; Kidney - metabolism; Kidney - pathology; kidneys; leptin receptors; Male; Medical sciences; Metabolic diseases; Metabolic syndrome; Metabolic Syndrome - diet therapy; Metabolic Syndrome - metabolism; Metabolic Syndrome - pathology; Miscellaneous; noninsulin-dependent diabetes mellitus; nonsense mutation; obesity; Obesity - diet therapy; Obesity - metabolism; Obesity - pathology; Other metabolic disorders; pancreas; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Rats; Rats, Inbred SHR; Rats, Inbred WKY; SHR/NDmcr-cp; Type 2 diabetes; Type 2 diabetes; Diabetogenic diet; SHR/NDmcr-cp; Islet hyperplasia; Metabolic syndrome; Endocrinopathy; Modification; Animal model; Rat; Hyperplasia; Autoimmune disease; Cardiovascular disease; Endocrine pancreas; Immunopathology; Nutrition; Rodentia; Langerhans islet; Metabolic diseases; Metabolism; Feeding; Vertebrata; Anatomic pathology; Mammalia; Diet; Type 1 diabetes
• ISSN: 0940-2993; 1618-1433
• DOI: 10.1016/j.etp.2010.09.006

SHR/NDmcr-cp (SHR/NDcp) rats, which carry a nonsense mutation of the leptin receptor gene, are known to spontaneously develop hypertension, obesity and hyperlipidemia, and have therefore found use as an animal model of the metabolic syndrome and type 2 diabetes. However, some recent studies on SHR/NDcp rats revealed only mild elevation of blood glucose levels. To investigate whether metabolic factors including blood glucose and histopathological alterations of SHR/NDcp rats deteriorate with a diabetogenic diet, biochemical and histopathological examinations were conducted with animals fed normal or diabetogenic diets for 20 weeks. SHR/NDcp rats receiving the normal diet displayed obesity, hypertension, hyperlipidemia, and mild elevation of blood glucose and HbA1c levels. Urinary glucose excretion was noted in only 1 out of 6 animals. Histologically, macro- and micro-vesicular steatosis in the liver, glomerular and tubular damages in the kidney and islet hyperplasia mainly of beta cells in the pancreas were characteristically noted. In SHR/NDcp rats fed the diabetogenic diet, obesity was more severe, with higher blood glucose and HbA1c levels, increased numbers of animals with urinary glucose excretion, and more pronounced hepatic steatosis and renal tubular changes. However, elevation of blood glucose levels and urinary glucose excretion proved transient. These observations indicate that the diabetic state and associated histopathological alterations in SHR/NDcp rats are exacerbated by feeding a diabetogenic diet, but the effects are limited. Elevated islet function with compensative insulin secretion might be related to amelioration of the hyperglycemic state. Further diet modification could be needed to induce a more prominent and persistent diabetic state in SHR/NDcp rats.