Regulation of calcium handling by rat parotid acinar cells.
Salivary gland fluid secretion following neurotransmitter stimulation is Ca2+-dependent. We have studied the control of cellular Ca2+ following secretory stimuli in rat parotid gland acinar cells. After muscarinic-cholinergic receptor activation, cytosolic Ca2+ is elevated 4-5 fold, due to both intracellular Ca2+ pool mobilization and extracellular Ca2+ entry. Fluid movement ensues due to the Ca2+-activated enhancement of membrane permeability to K+ and Cl-. Basal cytosolic Ca2+ levels are tightly controlled at approximately 150-200 nM through the action of high affinity and high capacity ATP-dependent Ca2+ transporters in the basolateral and endoplasmic reticulum membranes. Activity of these Ca2+ transporters can be modulated to facilitate rapid responsiveness and a sustained fluid secretory response necessary for alimentary function.
Baum
B J
BJ
Clinical Investigations and Patient Care Branch, National Institute of Dental Research, Bethesda, MD 20892.
Ambudkar
I S
IS
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D010306:Parotid Gland / Q000166:cytology / Q000502:physiology*; D051381:Rats
D000255:Adenosine Triphosphate; D002118:Calcium