Spatial localization of the stimulus-induced rise in cytosolic Ca2+ in bovine adrenal chromaffin cells. Distinct nicotinic and muscarinic patterns.
The spatial distribution of the intracellular free Ca2+ (Ca2+i) rise elicited by different stimuli in bovine adrenal chromaffin cells was examined in single fura-2-loaded cells. In response to the potent secretagogues nicotine and high K+, Ca2+i was initially localized exclusively to the entire subplasmalemmal area of the cell. In response to the ineffective secretagogues, methacholine and muscarine, the rise in Ca2+i originated only in one pole of the cell and even at the peak of the response Ca2+ was still generally restricted to this same area of the cell. These results suggest that the triggering of exocytosis from these cells requires a specific spatial distribution of Ca2+i.
Cheek
T R
TR
AFRC Unit of Insect Neurophysiology and Pharmacology, Department of Zoology, Cambridge, England.
O'Sullivan
A J
AJ
Moreton
R B
RB
Berridge
M J
MJ
Burgoyne
R D
RD
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002838:Chromaffin System / Q000187:drug effects / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes; D016257:Fura-2; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D016210:Methacholine Chloride; D008688:Methacholine Compounds / Q000494:pharmacology; D009116:Muscarine / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000502:physiology*; D013873:Thionucleotides / Q000494:pharmacology
D001572:Benzofurans; D005456:Fluorescent Dyes; D008688:Methacholine Compounds; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D013873:Thionucleotides; D016210:Methacholine Chloride; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D009538:Nicotine; D009116:Muscarine; D006160:Guanosine Triphosphate; D011188:Potassium; D002118:Calcium; D016257:Fura-2