Selective use of a reserved mechanism for inducing calcium oscillations.
Concentration-dependent transformation of hormone- and neurotransmitter-induced calcium oscillation is a common phenomenon in diverse types of cells especially of the secretory type. The rodent submandibular acinar cells are an exception to this rule, which show elevated plateau increase in intracellular calcium under all stimulatory concentrations of both norepinephrine and acetylcholine. However, under depolarized state this cell type could also show a variation of periodic calcium changes. This reserved mechanism of calcium oscillation is jump-started by depolarization only with muscarinic cholinergic stimulation, but not with adrenergic stimulation. This latter effect is attributable to alpha receptor activation, not due to simultaneous activation of alpha and beta receptors, with beta receptor activation only serving to enhance the magnitude. These data suggest that this reserved mechanism for inducing calcium oscillation can be selectively used only by specific receptor-signaling pathways, and may therefore partly explain the long-known differences between secretion induced by sympathetic and parasympathetic stimulation in the submandibular gland.
Ma
Chun Yan
CY
Institute of Cell Biology, Beijing Normal University, Beijing 100875, China.
Chen
Chun Ying
CY
Cui
Zong Jie
ZJ
D000109:Acetylcholine / Q000737:chemistry; D000818:Animals; D001671:Biochemistry / Q000379:methods*; D002118:Calcium / Q000378:metabolism*; D002465:Cell Movement; D004305:Dose-Response Relationship, Drug; D022781:Hepatocytes / Q000378:metabolism; D007477:Ions; D008297:Male; D009638:Norepinephrine / Q000737:chemistry; D009991:Oscillometry; D011188:Potassium / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013363:Submandibular Gland / Q000166:cytology / Q000378:metabolism; D013997:Time Factors
D007477:Ions; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine