A muscarinic receptor agonist mobilizes Ca2+ from caffeine and inositol-1,4,5-trisphosphate-sensitive Ca2+ stores in cat adrenal chromaffin cells.
To gain some understanding of the characteristics of intracellular Ca2+ stores of cat adrenal chromaffin cells, we investigated the effects of ryanodine, a blocker of Ca(2+)-induced Ca2+ release channels in muscle, on both cytosolic Ca2+ concentration and catecholamine secretion induced by caffeine or methacholine. The results suggest that Ca2+ stores consist of at least two compartments, one which is sensitive to both caffeine and inositol-1,4,5-trisphosphate (IP3), and the other which is sensitive to IP3 alone.
Sorimachi
M
M
Department of Physiology, Kagoshima University, School of Medicine, Japan.
Yamagami
K
K
Nishimura
S
S
D000311:Adrenal Glands / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002118:Calcium / Q000493:pharmacokinetics*; D002415:Cats; D002838:Chromaffin System / Q000166:cytology / Q000378:metabolism*; D005470:Fluorometry; D016257:Fura-2; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology*; D016210:Methacholine Chloride / Q000494:pharmacology; D010277:Parasympathomimetics / Q000494:pharmacology*; D011976:Receptors, Muscarinic / Q000502:physiology; D012433:Ryanodine / Q000494:pharmacology
D010277:Parasympathomimetics; D011976:Receptors, Muscarinic; D016210:Methacholine Chloride; D012433:Ryanodine; D002110:Caffeine; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium; D016257:Fura-2