Development of a new diet-induced obesity (DIO) model using Wistar lean rats.

Obesity is an increasingly severe socioeconomic health issue worldwide. Rodents with diet-induced obesity (DIO) are widely used as models of obesity. The main aim of this study was to establish a DIO model using Wistar lean (+/+ or +/-) rats by feeding a high-fat diet (45 kcal% fat) to dams during the latter term of gestation and the lactation period.

Mechanisms for the reduction of 24,25-dihydroxyvitamin D3 levels and bone mass in 24-hydroxylase transgenic rats.

24-Hydroxylase (CYP24) is an enzyme distributed in the target tissues of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. Two functions for this enzyme have been reported: One is production of 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] and the other is inactivation of 1alpha,25(OH)2D3. To elucidate other physiologic roles of CYP24 in vivo, we previously generated rats that constitutively express the CYP24 gene.

Characterization of transgenic rats constitutively expressing vitamin D-24-hydroxylase gene.

Vitamin D-24-hydroxylase (CYP24) is one of the enzymes responsible for vitamin D metabolism. CYP24 catalyzes the conversion of 25-hydroxyvitamin D(3) [25(OH)D(3)] to 24,25-dihydroxyvitamin D(3) [24,25(OH)(2)D(3)] in the kidney. CYP24 is also involved in the breakdown of 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], the active form of vitamin D(3).