Cyclic nucleotide‐activated channels in the frog olfactory receptor plasma membrane

[摘要]

Patch clamp technique was used to record cyclic nucleotide-dependent current of the frog olfactory receptor cell plasma membrane. Data obtained indicate that the channels passing this current are permeable to Ca²⁺ or Mg²⁺ and moderately selective for monovalent cations according to the sequence Li⁺, Na⁺, K⁺ > Rb⁺ > Cs⁺ and are effectively blocked by 1-cis-diltiazem and 3′,4′-dichlorobenzamil. The conductance of single cyclic nucleotide-gated channels in solutions with low Ca²⁺ and Mg²⁺ content is about 19 pS. The results demonstrate that cyclic nucleotide-activated channels of olfactory receptor cells are virtually identical to photoreceptor ones.

[学科分类] 生物化学/生物物理

[关键词] Olfactory receptor cell;Cyclic nucleotide-activated channel;Single channel recording;cAMP;cyclic adenosine-3′;5′-monophosphate;cGMP;cyclic guanosine-3′;5′-monophosphate;8BrcGMP;cyclic 8-bromoguanosine-3′;5′-monophosphate;ATP;adenosine-5′-triphosphate;GTP;guanosine-5′-triphosphate;EDTA;ethylenedia-minetetraacetic acid;EGTA;ethylene glycol bis(2-aminoethylether)-N;N;N′-tetraacetic acid;Hepes;4-(2-hydroxyethyl)-1-piperazine-ethanesulfonic acid;DCPA;3′;4′-dichlorobenzamil;OR;olfactory receptor cell;PR;photoreceptor cell;CN-channels (conductance);cyclic nucleotide-activated channels (conductance);low Ca2+;Mg2+ solution;solution containing 10−7 M Ca2+ and Mg2+ or less