Ryanodine receptor expression is associated with intracellular Ca2+ release in rat parotid acinar cells.
The ryanodine receptor mediates intracellular Ca2+ mobilization in muscle and nerve, but its physiological role in nonexcitable cells is less well defined. Like adenosine 3',5'-cyclic monophosphate and inositol 1,4,5-trisphosphate, cyclic ADP-ribose (0.3-5 microM) and ADP (1-25 microM) produced a concentration-dependent rise in cytosolic Ca2+ in permeabilized rat parotid acinar cells. Adenosine and AMP were less effective. Ryanodine markedly depressed the Ca2+-mobilizing action of the adenine nucleotides and forskolin in permeabilized cells and was likewise effective in depressing the action of forskolin in intact cells. Cyclic ADP-ribose-evoked Ca2+ release was enhanced by calmodulin and depressed by W-7, a calmodulin inhibitor. A fluorescently labeled ligand, 4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3,4-diaza-s-indac ene-3-propionic acid-glycyl ryanodine, was synthesized to detect the expression and distribution of ryanodine receptors. In addition, ryanodine receptor expression was detected in rat parotid cells with a sequence highly homologous to a rat skeletal muscle type 1 and a novel brain type 1 ryanodine receptor. These findings demonstrate the presence of a ryanodine-sensitive intracellular Ca2+ store in rat parotid cells that shares many of the characteristics of stores in muscle and nerve and may mediate Ca2+-induced Ca2+ release or a modified form of this process.
Zhang
X
X
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 14214, USA.
Wen
J
J
Bidasee
K R
KR
Besch
H R
HR
Rubin
R P
RP
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D036563:Cyclic ADP-Ribose; D000242:Cyclic AMP / Q000378:metabolism; D005456:Fluorescent Dyes; D005786:Gene Expression Regulation / Q000187:drug effects; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D010306:Parotid Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D012433:Ryanodine / Q000494:pharmacology*; D019837:Ryanodine Receptor Calcium Release Channel / Q000096:biosynthesis* / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013449:Sulfonamides / Q000494:pharmacology
D002147:Calmodulin; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel; D013449:Sulfonamides; D036563:Cyclic ADP-Ribose; D012433:Ryanodine; D005576:Colforsin; D000246:Adenosine Diphosphate Ribose; C017967:W 7; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine