Endogenous Release of Secretin From the Hypothalamus

摘要

Previous studies demonstrated that secretin could be re-leased from the cerebellum, where it exerts a facilitatory action on the GABAergic inputs into the Purkinje neurons. In the present article, we provide evidence of the endogenous release of secretin in the hypotha-lamus and the mechanisms underlying this release. Incubation of the hypothalamic explants with KCI induces the release of secretin to 4.35 ± 0.45-fold of the basal level. This K~+-induced release was tetrodotoxin and cadmium sensitive, suggesting the involvement of voltage-gated sodium and calcium channels. The use of specific blockers further revealed the involvement of L-, N-, and P-type high voltage-activated (HVA) calcium channels. Results present in the current article provide further and more solid evidence of the role of secretin as a neuropeptide in the mammalian central nervous system.