Intermittent hypoxic conditioning (ihc) modulates delta opioid receptor (dor) phenotypes

IHC mediated cardioprotection is dependent on the DOR in dogs. It is predominantly expressed on cholinergic fibers and recruits both vagotonic and vagolytic pathways. Ganglioside GM-1 treatment decreases recruitment vagolytic DOR pathways. Vagal stimulation is cardioprotective, therefore we tested the hypothesis that IHC modulates the receptor phenotype in favor of the vagotonic receptor subtype by changing expression and DOR and GM-1. Dogs were assigned to 3 groups: non-hypoxic sham, IHC, or IHC + N. Atrial tissue was collected for biochemical analysis. Immunoblot densitometry was used to measure DOR protein content and immunocytochemistry followed by line scan intensity analysis of photomicrographs was used to evalaute GM-1. There was an increase in DOR following IHC+N relative to sham (p