Acute effects of zinc and insulin on arcuate anorexigenic proopiomelanocortin neurons

Background and Purpose Acute insulin administration hyperpolarized, with concomitant decrease of firing rate, a subpopulation of arcuate proopiomelanocortin (POMC) and neuropeptide Y/agouti‐related peptide cells. This rapid effect on cellular activity has been proposed as a cellular correlate of insulin effects on energy balance and glucose homoeostasis. Recent evidence suggests that zinc in mammalian insulin formulations is required for the insulin‐induced inhibition of arcuate POMC neurons, while guinea pig insulin, which fails to bind zinc, activates POMC neurons in mice. Here, we tested the effects of zinc and insulin formations on arcuate POMC neurons.