Corticotropin‐Releasing Factor Binding Sites Undergo Axonal Transport in the Rat Vagus Nerve

Corticotropin‐releasing factor (CRF) binding sites were found to be present in the rat vagus nerve and underwent axonal transport. Binding sites accumulated on both sides of ligatures placed on the nerve and at similar rates following ligation of right or left cervical vagal trunks of either male or female rats. CRF binding sites also accumulated proximal and distal to ligatures on subdiaphragmatic vagal trunks. Binding was specific, reversible and inhibited by the CRF receptor antagonist α‐helical‐CRF(9–41). [125l]Tyr0‐ovine‐CRF binding to rat vagus nerve was not guanine nucleotide‐sensitive. CRF and cholecystokinin binding sites were transported at a similar rate in the cervical vagus, although turnover of CRF binding sites was more rapid. No differences in CRF binding site transport were observed between Zucker rats of lean or obese genotype.