Fig. 3

Effects of OXT infusion on adipocyte size, lipolysis and adipose tissue macrophage infiltration. (Panel a) Adipocyte size in epididymal tissues of Vehicle (n = 8) or OXT-treated db/db mice (n = 10) and lean control mice (n = 6). (Panel b) Lipolysis of triglycerides in isolated adipocytes from db/db mice incubated with increasing concentration of OXT for 30 min evaluated by release of free fatty acids. Adipocytes isolated from 3 or 4 mice were pooled and assayed in triplicate at each OXT dose. Data represent the mean for each dose from three separate experiments. OXT significantly increased lipolysis in a dose dependent manner; p = 0.003 for OXT dose and * indicates p < 0.01 compared to no oxytocin at all doses by post-hoc analysis

(Panel c). Macrophage infiltration into adipose tissue of Vehicle (n = 8) or OXT-treated db/db mice (n = 10) and lean control mice (n = 6) assessed by immunohistochemistry for F4/80 antigen expression. (Panel d) Densities of crown-like structures in epididymal fat pads of db/db mice treated with vehicle (n = 8) or OXT (n = 9) and lean controls (n = 6) expressed as number per microscopic field (average of 5 fields per mouse tissue). (Panel e). Representative photomicrographs of F4/80 immunostained epididymal fat from vehicle and OXT treated db/db mice and lean control mice, bar = 50 μm. Data were expressed as mean ± SEM for each respective group.