LEP and obesity due to melanocortin 4 receptor deficiency: As expected from previous studies of obesity, concentrations of leptin were higher, and adiponectin lower, in OB compared to NW medium.15, 21, 22, 23, 24 Exposure to NW and OB media was associated with changes in MA function in comparison to the control medium, indicating that the presence of adipokines in the culture medium modulates vascular reactivity.