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Chem Senses

Title:		Pharmacological investigation of protein kinase C- and cGMP-dependent ion channels in cultured olfactory receptor neurons of the hawkmoth Manduca sexta
Author(s):		Dolzer J; Krannich S; Stengl M;
Address:		"Department of Biology, Animal Physiology, Philipps-University of Marburg, Karl-von-Frisch-Strasse 8, Marburg D-35032, Germany"
Journal Title:		Chem Senses
Year:		2008
Volume:		20080716
Issue:		9
Page Number:		803 - 813
DOI:		10.1093/chemse/bjn043
ISSN/ISBN:		1464-3553 (Electronic) 0379-864X (Print) 0379-864X (Linking)
Abstract:		"In the hawkmoth Manduca sexta, pheromone stimuli of different strength and duration rise the intracellular Ca2+ concentration in olfactory receptor neurons (ORNs). While second-long pheromone stimuli activate protein kinase C (PKC), which apparently underlies processes of short-term adaptation, minute-long pheromone stimuli elevate cyclic guanosine monophosphate (cGMP) concentrations, which correlates with time courses of long-term adaptation. To identify ion channels involved in the sliding adjustment of olfactory sensitivity, inside-out patch clamp recordings on cultured ORNs of M. sexta were performed to characterize Ca2+-, PKC-, and cGMP-dependent ion channels. Stepping to positive holding potentials in high intracellular Ca2+ elicits different Ca2+-dependent ion channels, namely small-conductance channels (2-20 ps), medium-conductance channels (20-100 ps), and large-conductance channels (>100 ps). Ion channels of 40, 60, and 70 ps opened after PKC activation, whereas 10- and >100-ps channels were observed less frequently. Application of 8-bromo cyclic guanosine monophosphate opened 55- and 70-ps channels and increased the open probability of >100-ps channels, whereas even in the presence of phorbol ester 40-ps channels were inhibited. Thus, cGMP elevations activate a different set of ion channels as compared with PKC and suppress at least one PKC-dependent ion channel"
Keywords:		"Animals Calcium/pharmacology Cells, Cultured Cyclic GMP/*metabolism Electrophysiology Ion Channels/*metabolism Manduca/*cytology/drug effects/enzymology/*metabolism Olfactory Receptor Neurons/cytology/drug effects/*metabolism Protein Kinase C/*metabolism;"
Notes:		"MedlineDolzer, Jan Krannich, Steffi Stengl, Monika eng Research Support, Non-U.S. Gov't England 2008/07/19 Chem Senses. 2008 Nov; 33(9):803-13. doi: 10.1093/chemse/bjn043. Epub 2008 Jul 16"