For CM secretion, chow diet-fed mice were fasted for 16 h and injected with 500 mg tyloxapol/kg body weight (Merck KGaA; Darmstadt, Germany) to inhibit peripheral lipolysis. Thirty minutes later, mice were gavaged with 200 μl olive oil as a substrate to trigger CM synthesis (Jackson et al., 2002 (link)). Blood was taken prior to the injection as well as 1, 2, 3, and 4 h post olive oil gavage. Plasma TG and TC concentrations were measured as described above. For analysis of CM size, mice were fasted for 4 h prior to injection of tyloxapol (500 mg/kg body weight). One hour later, mice were administered an olive oil bolus (200 μl) and blood was collected 90 min post gavage. Plasma was obtained via centrifugation (7 min at 5,200 x g and 4°C) and pooled for each genotype. Samples (125 μl) were mixed with 280 μl of buffer (PBS, 2 mM benzamidine, 4 M KBr) and 4 mL of 0.9% NaCl before ultracentrifugation for 45 min. CMs were isolated from the upper phase and size was measured in technical triplicate by light scattering (Malvern Zetasizer, Malvern Panalytical GmbH, Kassel, Germany).
VLDL secretion was determined in 16 h-fasted mice after tyloxapol injection (500 mg/kg body weight). Blood was taken prior to injection as well as 1, 2, 4, and 6 h post-injection.
VLDL secretion was determined in 16 h-fasted mice after tyloxapol injection (500 mg/kg body weight). Blood was taken prior to injection as well as 1, 2, 4, and 6 h post-injection.