The single dose poloxamer 407 model of hyperlipidemia; systemic effects on lipids assessed using pharmacokinetic methods, and its effects on adipokines

Abstract

Purpose: The induction of hyperlipidemia using poloxamer 407 (P407) is gaining use for studying the effect of the condition on drug pharmacokinetics. Although a single intraperitoneal dose of P407 causes a rapid onset of hyperlipidemia, the initial lipid concentrations are much higher than seen in humans. The hyperlipidemia is also reversible in nature. Here, pharmacokinetic methods were used to assess the P407 dose response on serum lipids, adipokines and cytokines. Methods: Single 0.5 and 1 g/kg doses of P407 were injected into rats followed by blood collection at various times for up to 12 d. Serum was assayed for lipids, selected adipokines and cytokines. Results: As expected, large increases in lipid levels were seen by 36 h after dosing. Using area under the concentration vs. time curve as a measure of systemic lipid exposure, P407 increased serum baseline corrected serum lipids in a nearly dose proportional fashion. The maximum increase in lipids was observed at ~36 h, with most lipids remaining elevated for up to ~180 h, although for the 1 g/kg dose triglyceride concentrations had still not quite returned to baseline by 12 days postdose. In addition to changes in lipids, P407 significantly increased serum leptin and decreased the serum adiponectin concentrations but did not affect cytokine levels. Conclusion: Depending on study aims, for the use of the model it may be beneficial to perform single-dose assessments at time points later than 36 h when the lipoprotein concentrations will be more similar to those seen in patient with hyperlipidemia.