Blood Pressure Characteristics of Female Spontaneously Diabetic Torii-Leprfa Rats

Abstract

ABSTRACT. Blood pressure in female SDT-fa/fa rats was periodically investigated at ages 8, 16, and 24 weeks. Furthermore, an insulin therapy was performed for 5 weeks in the female rats at age 11 weeks, and the change of blood pressure was examined. In addition to obesity, hyperglycemia, hyperinsulinemia, and hyperlipidemia, hyperleptinemia and increased urinary angiotensinogen level were observed during the experimental period. Blood pressure was elevated at ages 8 and 16 weeks, but that at 24 weeks was comparable to that in Sprague-Dawley (SD) rats. Heart rate was decreased from age 8 to 24 weeks. Insulin therapy induced good glycemic control and improvement of hyperlipidemia, but the blood pressure was not reduced. Blood pressure in female SDT-fa/fa rats was elevated temporarily. The blood pressure was not decreased by insulin treatment. SDT-fa/fa rat is a useful model to investigate the relation between diabetes mellitus and hypertension. The incidence of metabolic syndrome increases rapidly all over the world. The metabolic syndrome is characterized by several metabolic risk factors related with obesity and diabetes [4,28]. Because of the elevated risk of cardiovascular disease related with metabolic syndrome, it is a pivotal theme to prevent the global epidemic [7,28]. Metabolic syndrome is characterized by metabolic abnormalities, including abdominal obesity, dyslipidemia, glucose intolerance, insulin resistance, and elevated blood pressure.To clarify the complicated features of the disease, studies using animal models are essential. In particular, the development of metabolic syndrome animal models and pathophysiological analyses of the models are very important to aid in clarification of the pathogenesis and the patterns of progression in the human disease course. Spontaneously Diabetic Torii-Lepr fa (SDT-fa/fa) rat, established by introducing the fa allele of the Zucker fatty rat into the SDT rat genome, represents a new model of obese type 2 diabetes [18]. SDT-fa/fa rats of both sexes exhibited hyperphagia and obesity after weaning, and the hyperglycemia and the hyperlipidemia were observed from a young age, 4-6 weeks. Moreover, fat accumulation in the SDT-fa/fa rats was remarkable, and the visceral fat weight was obviously increased with aging [11,20]. Interestingly, blood pressure in male SDT-fa/fa rats was increased from 8 to 24 weeks of age [9]. Since obesity, hyperglycemia, hyperlipidemia, insulin resistance, and hypertension are observed in male SDT-fa/fa rats, the rat is also expected as an animal model of metabolic syndrome. Moreover, female SDT-fa/fa rats exhibited obesity, insulin resistance, hyperglycemia, and hyperlipidemia. The female SDT-fa/fa rat has the potential to become an important animal model of type 2 diabetes mellitus with obesity, especially for women, for which few models currently exist. However, the blood pressure has not yet been examined in the female SDT-fa/fa rat. In the present study, the blood pressure was periodically investigated in female SDT-fa/fa rats. Furthermor...

Physiological changes induced by salt intake in female Spontaneously Diabetic Torii‐Leprfa (SDT fatty) rat, a novel obese type 2 diabetic model

“…Also, female SDT fatty rats showed a temporary increase of blood pressure (Ishii et al . ). In the present study, physiological changes in blood pressure and renal function were examined in female SDT fatty rats after salt loading.…”

“…Furthermore, SDT fatty rats showed an elevation of blood pressure, in addition to the above metabolic abnormalities (Ishii et al . 2010b, ). In a previous study, we investigated physiological changes induced by salt intake using male SDT fatty rats (Ohta et al .…”

Relationship between Immunological Abnormalities in Rat Models of Diabetes Mellitus and the Amplification Circuits for Diabetes

“…Spontaneously Diabetic Torii (SDT) rats have severe diabetic complications without obesity [48–51]. Recently, mating of ZF rats with SDT rats has also been carried out: the mated rats exhibited an increased risk of hypertension caused by DM with obesity [52, 53]. To our knowledge, there have been no reports on immunological abnormality in SDT rats.…”

Diabetic Complications in Obese Type 2 Diabetic Rat Models

“…The expansion of nodular lesions to mesangial matrix is characteristic in OLETF rats and SDT fatty rats. The reason SDT fatty rats showed a significant nodular lesion might be related with an elevation of blood pressure, one of the characteristics in SDT fatty rats [28, 29]. The tubulointerstitial scaring and inflammation were observed in ZDF rats and SDT fatty rats.…”