title: Cyclic GMP regulates free cytosolic calcium in the pancreatic acinar cell.
abstract: The present studies were performed in order to measure the effects of cyclic GMP (cGMP) on the regulation of free cytosolic calcium [( Ca2+]i) in the pancreatic acinar cell. In guinea pig dispersed pancreatic acini the findings demonstrated that the Ca2+ ionophore, Br A23187, caused a sustained increase in [Ca2+]i in the presence of 3 mM CaCl2 in the media and a transient 20 fold rise in cellular cGMP followed by a sustained 3-4 fold rise in cellular cGMP. Increasing cellular cGMP with nitroprusside, hydroxylamine or dibutyryl cGMP had no effect on resting [Ca2+]i. However, these agents attenuated the increase in [Ca2+]i resulting from Br A23187-induced Ca2+ influx. Nitroprusside also attenuated the carbachol-induced sustained rise in [Ca2+]i that resulted from Ca2+ influx. The nitroprusside effect on carbachol-stimulated acini occurred without decreasing Ca2+ influx across the plasma membrane or alteration in the mobilization of Ca2+ from the intracellular agonist-sensitive pool. Inhibition of the increase in cellular cGMP caused by Br A23187 by the guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY83583), resulted in augmentation of the increase in [Ca2+]i. This augmentation was reversed with dibutyryl cGMP. These results indicated that cGMP regulated [Ca2+]i in the pancreatic acinar cell. The mechanism involves the removal of Ca2+ from the cytoplasm.
authors.affiliation: Department of Medicine, Veterans Administration, San Diego, California.
authors.forename: S J
authors.initials: SJ
authors.lastname: Pandol
authors.forename: M S
authors.initials: MS
authors.lastname: Schoeffield-Payne
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D006152:Cyclic GMP / Q000502:physiology*; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism*; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006168:Guinea Pigs; D006898:Hydroxylamines / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010179:Pancreas / Q000166:cytology* / Q000378:metabolism; D013189:SRS-A / Q000037:antagonists & inhibitors
chemical_list: D000634:Aminoquinolines; D006898:Hydroxylamines; D013189:SRS-A; D009599:Nitroprusside; D003995:Dibutyryl Cyclic GMP; D000001:Calcimycin; C041715:6-anilino-5,8-quinolinedione; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D002118:Calcium