https://www.selleckchem.com/products/sar131675.html The companion dog has recently been promoted as powerful translational model of aging. However, while dogs share environments with their human owners and develop many of the same age-related morbidities, little is known about the underlying mechanisms that drive their health and longevity. In addition, dogs have a well described phenotypic pattern in which small dogs live significantly longer than large dogs, such that weight can be used as a crude proxy for longevity. To investigate this pattern, we completed a small lipidomics study on 41 dogs in the Birmingham, Alabama, United States, area to determine individual circulating lipids that were associated with age and body weight. We discovered that sphingomyelins were significantly higher in large, short-lived dogs, independent of age, and triglycerides were higher in older dogs of all sizes. Our results point towards physiological differences that may explain a portion of the variation in longevity seen in companion dogs. The levels of adrenal androgens are increased through the action of steroidogenic enzymes with morphological changes in the adrenal zona reticularis. We investigated longitudinal changes in androgen levels and steroidogenic enzyme activities during early childhood. From a prospective children's cohort, the Environment and Development of Children cohort, 114 boys and 86 girls with available blood samples from ages 2, 4, and 6 years were included. Serum concentrations of adrenal androgens using liquid chromatography-tandem mass spectrometry and steroidogenic enzyme activity calculated by the precursor/product ratio. During ages 2 to 4 years, 17,20-lyase and dehydroepiandrosterone (DHEA) sulfotransferase activities increased (P < 0.01 for both in boys). During ages 4 to 6 years, 17,20-lyase activity persistently increased, but 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD activities decreased (P < 0.01 for all). Serum DHEA sulfate (DHEA-S) leve