Monkey adrenal chromaffin cells express ?6?4* nicotinic acetylcholine receptors.

ABSTRACT: Nicotinic acetylcholine receptors (nAChRs) that contain ?6 and ?4 subunits have been demonstrated functionally in human adrenal chromaffin cells, rat dorsal root ganglion neurons, and on noradrenergic terminals in the hippocampus of adolescent mice. In human adrenal chromaffin cells, ?6?4* nAChRs (the asterisk denotes the possible presence of additional subunits) are the predominant subtype whereas in rodents, the predominant nAChR is the ?3?4* subtype. Here we present molecular and pharmacological evidence that chromaffin cells from monkey (Macaca mulatta) also express ?6?4* receptors. PCR was used to show the presence of transcripts for ?6 and ?4 subunits and pharmacological characterization was performed using patch-clamp electrophysiology in combination with ?-conotoxins that target the ?6?4* subtype. Acetylcholine-evoked currents were sensitive to inhibition by BuIA[T5A,P6O] and MII[H9A,L15A]; ?-conotoxins that inhibit ?6-containing nAChRs. Two additional agonists were used to probe for the expression of ?7 and ?2-containing nAChRs. Cells with currents evoked by acetylcholine were relatively unresponsive to the ?7-selctive agonist choline but responded to the agonist 5-I-A-85380. These studies provide further insights into the properties of natively expressed ?6?4* nAChRs.

SUBMITTER: Hernandez-Vivanco A 

PROVIDER: S-EPMC3984115 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature