Figure 7: MBH oleic acid sensory mechanisms in HFD-induced hypertriglyceridemia.

(a) Experimental protocol: three days before the experimental day, rats were introduced to and maintained on a lard oil-enriched HFD. In a separate set of experiments shown (h,i), rats underwent a hepatic vagotomy (HepVx) or sham operation (ShamVx) immediately preceding vascular catheterization. MBH infusions of vehicle, oleic acid, OAG or diazoxide were commenced at t=−10 min. (b) Plasma TG concentrations and (c) per cent suppression of VLDL-TG secretion rate as compared with control with MBH infusion of vehicle (white open squares, n=6), oleic acid (grey circles, n=5), OAG (black squares, n=6) or diazoxide (grey triangles, n=5). *P<0.04; **P<0.008 HFD+OAG versus HFD+vehicle. †P<0.02, ††P<0.007 HFD+diazoxide versus HFD+vehicle. Data are presented as mean+s.e.m. (d) Plasma TG in non-tyloxapol-treated rats given MBH infusions of vehicle (n=8), oleic acid (1 mM, n=6), OAG (250 μM, n=4) or diazoxide (46.7 μM, n=5). *P<0.05; **P<0.008 HFD+OAG versus HFD+vehicle. †P<0.05, ††P<0.007 HFD+diazoxide versus HFD+vehicle. Plasma (e) glucose, (f) FFA and (g) insulin concentrations in HFD-fed rats from experiments shown (b,c). (h) Plasma TG concentrations and (i) per cent suppression of VLDL-TG secretion rate as compared with respective HFD-fed HepVx controls in HFD-fed sham-operated rats with MBH infusion of OAG (black squares, n=8) or diazoxide (dark grey circles, n=6) or vagotomized rats with OAG (white squares, n=5), or diazoxide (light grey circles, n=5). *P<0.05; **P<0.004 HFD+ShamVx+OAG versus HFD+HepVx+OAG. †P<0.05, ††P<0.007 HFD+ShamVx+diazoxide versus HFD+HepVx+diazoxide. Data are presented as mean+s.e.m. Statistical significance determined by Dunnett’s post hoc test after analysis of variance (ANOVA). For measurements over time, repeated measures ANOVA was used followed by Duncan’s post hoc test.