2016 ACVIM Forum Research Abstract Program

Hydrocortisone administration resulted in increased abdominal visceral fat mass on days 30, 60, and 90 compared with fat mass before administration (day 0). Additionally, visceral fat area at the L3 level also was increased during hydrocortisone administration. Serum leptin concentrations began to increase on day 1 of hydrocortisone administration and were significantly increased on days 1, 3, 7, 30, 60, and 90 compared with concentrations on day 0. Serum adiponectin concentrations on days 1, 3, 7, 30, 60, and 90 were decreased compared with concentrations on day 0. The mRNA expressions of leptin and adiponectin in the abdominal fat were increased on day 30 compared with expressions on day 0, but the expressions were decreased on days 60 and 90 compared with those on day 30. We identified a correlation between serum leptin and adiponectin concentrations and visceral fat distribution. This study showed that hydrocortisone administration affected visceral fat distribution and serum concentrations of leptin and adiponectin by dysregulating leptin and adiponectin expression. Recombinant DNA technology has been used to modify the structure of human insulin to yield analogs that are more rapidlyacting than regular insulin or have a longer duration of action than NPH insulin. The long-acting insulin analogs have been studied in cats and are routinely used to manage feline diabetics. More recently, the isoglycemic clamp method has been used to study the metabolic effect of a rapid-acting insulin analog in healthy cats. Generating time-action profiles to study the pharmacodynamic properties of insulin formulations does not require measurement of plasma insulin concentrations, but if measured, they provide useful pharmacokinetic data that can be used to validate the timeaction profiles. The Iso-Insulin ELISA (Mercodia AB, Uppsala, Sweden) is used to measure the concentration of insulin analogs in plasma. A previous study using actual feline serum samples with a wide range of insulin concentrations measured by a commercial ELISA failed to detect cross-reactivity of feline insulin with the Iso-Insulin ELISA.