A study of cardiovascular function in Tsumura Suzuki obese diabetes, a new model mouse of type 2 diabetes.
Diabetes mellitus is a well known and important risk factor for cardiovascular diseases, including heart failure. A new model of Type 2 diabetes, Tsumura Suzuki Obese Diabetes (TSOD) mice, was introduced recently into the research field of diabetes. The cardiac functions of TSOD mice were studied in comparison with Tsumura Suzuki Non Obesity (TSNO, non-diabetic control) mice, for the first time. In vivo cardiovascular functions were measured by echocardiography and cardiac catheterization at 7, 12 and 18 months old. TSOD mice had no deterioration of cardiac function despite the long-term persistence of severe obesity, hyperglycemia, hyperinsulinemia and hyperlipidemia, including high density lipoprotein (HDL)-cholesterol. No histopathological abnormalities were observed in the heart of TSOD mice, while several histological abnormalities were observed in the pancreas and kidney of TSOD mice. To investigate vascular endothelium function at 7 months old, intravenous injection of acetylcholine (ACh; 1, 3, 10 microg/kg)- and N(G)-nitro-L-arginine methyl ester (L-NAME; 50 mg/kg)-induced mean blood pressure (BP) changes were used. ACh decreased whereas L-NAME increased BP, and no significant differences in BP changes were observed between TSOD and TSNO mice. Moreover, ACh-induced relaxation of the thoracic aortae isolated from TSOD and TSNO mice with intact endothelium were not significantly different. These findings suggest that vascular endothelial cells in TSOD mice are not impaired. It was clearly demonstrated that despite obvious diabetes, cardiac functions of TSOD mice were not impaired even at 18 months old.
Research Institute of Pharmaceutical Sciences, Musashino University, Nishitokyo, Tokyo 202-8585, Japan. tomkawa@musashino-u.ac.jp
Tomie
T
Kawada
Shigeo
S
Miyata
Tsutomu
T
Shimada
Yoshiki
Y
Sanzen
Minami
M
Ito
Chieko
C
Hemmi
Seiichi
S
Iizuka
Wataru
W
Suzuki
Kiyoshi
K
Mihara
Masaki
M
Aburada
Mikio
M
Nakazawa
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic; D001794:Blood Pressure / Q000187:drug effects; D008076:Cholesterol, HDL / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000473:pathology; D004195:Disease Models, Animal; D004452:Echocardiography; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006943:Hyperglycemia / Q000097:blood; D006946:Hyperinsulinism / Q000097:blood; D006949:Hyperlipidemias / Q000097:blood; D007668:Kidney / Q000473:pathology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008820:Mice, Obese; D019331:NG-Nitroarginine Methyl Ester; D009765:Obesity / Q000097:blood / Q000473:pathology; D010179:Pancreas / Q000473:pathology*; D012016:Reference Values; D014664:Vasodilation / Q000187:drug effects
D008076:Cholesterol, HDL; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester