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Kazuo Ohwada

Publications and source records attributed to Kazuo Ohwada.

4 recordsLinked to original sources

Hereditary postprandial hypertriglyceridemic rabbit exhibits insulin resistance and central obesity: a novel model of metabolic syndrome.

OBJECTIVE: We have established a hereditary postprandial hypertriglyceridemic (PHT) rabbit. The present study was designed to define whether this rabbit model represents both insulin resistance and central obesity. METHODS AND RESULTS: Body weight, abdominal circumference, visceral fat weight, and glucose tolerance were compared between PHT and Japanese white (JW) rabbit. Plasma levels of triglycerides (TG), total cholesterol (TC), glucose, and insulin were measured before and after feeding. Abdominal circumference of PHT rabbit was larger than that of JW rabbit, with no difference in body mass index. Visceral fat accumulation was noted as obvious in mesenterium, retroperitoneal space, and epididymal area. Plasma TG and TC levels were high preprandially and markedly increased postprandially in PHT rabbit compared with JW rabbit. Although plasma glucose levels were comparable in both groups, plasma insulin levels were elevated in PHT rabbit. Glucose tolerance tests indicated that plasma insulin levels in PHT rabbit were consistently higher than in JW rabbit. A positive correlation was observed between plasma insulin levels and visceral fat weight in PHT rabbit. CONCLUSIONS: PHT rabbit shows insulin resistance along with central obesity. PHT rabbit will serve as a model for elucidating genetic predisposition and pathophysiology in metabolic syndrome.

Animals↗

Progression of severe atherosclerosis and increased arterial pulse pressure in the newly developed heritable mixed hyperlipidaemic rabbits.

We have recently segregated a new line of rabbit, named TGH, with severely high levels of plasma triglyceride and cholesterol. The aim of the present study was to investigate the progression of atherosclerosis and haemodynamic parameters in TGH rabbits. 2. Japanese white (JW) and TGH rabbits (24-27 months old) were anaesthetized with ketamine and xylazine. Plasma concentrations of triglyceride were 63.1 8.0 and 446.0 35.2 mg/dL in JW and TGH rabbits, respectively. Blood pressure was measured by a catheter implanted in the femoral artery. Histological examinations were performed using haematoxylin-eosin and elastica-Masson trichrome staining to detect atherosclerotic lesions. 3. The JW rabbits had no atherosclerotic lesions. In TGH rabbits, severe atherosclerotic lesions were observed throughout the aorta, especially in the aortic arch. Basal femoral arterial pressure was not significantly different between JW and TGH rabbits. However, the basal pulse pressure in TGH rabbits (48.3 4.5 mmHg) was significantly greater than that of JW rabbits (28.0 5.6 mmHg). Intravenous infusion of N(G)-nitro-L-arginine methyl ester (L-NAME; 26.9 mg/kg) increased the blood pressure of TGH and JW rabbits. There was no significant difference in the response to L-NAME between the two rabbit strains. 4. The present study shows that severe atherosclerotic changes develop in TGH rabbits and suggests that the hyperlipidaemia combined with hypercholesterolaemia and hypertriglyceridaemia is an important factor for promoting atherosclerosis in TGH rabbits. The greater pulse pressure in TGH rabbits may be due to the increased vascular stiffness with atherosclerosis. 5. This newly developed TGH rabbit line of heritable hypertriglyceridaemia with hypercholesterolaemia will become a useful animal model for studies on the role of hyperlipidaemia in the progression of atherosclerosis and in many atherosclerosis-related diseases.

Aging↗

Study of low-temperature (4 degrees C) transport of mouse two-cell embryos enclosed in oviducts.

PURPOSE: We examined usefulness of a mouse embryo transportation system for low-temperature transport of oviducts containing mouse two-cell embryos. METHODS: Oviducts containing two-cell mouse embryos were stored at 4 degrees C for 36 h. After that, embryos were collected and cultured for 96 h in Potassium Simplex Optimized Medium (KSOM) medium and evaluated for their rate of development to hatched blastocysts. Embryos were transferred to recipients, and the rate of survival to live young was investigated. The oviducts were then transported from Yamagata to Kumamoto (distance of approx. 1,000 km). At the destination, embryos were implanted in recipient dams and were studied to evaluate their survival to live young. RESULTS: After preservation for 36 h at 4 degrees C, 68.3% of two-cell embryos developed to hatched blastocysts. As a result of transplanting 546 embryos into 25 recipients, 109 normal live young mice were obtained; the rate of development was 20.0%. Results of oviduct transport from Yamagata to Kumamoto indicated that 30.2% of transplanted embryos developed to live young. CONCLUSION: Low-temperature transport of two-cell embryos in oviducts is useful as a method of shipping mouse embryos between institutes.

Animals↗