Beta-adrenergic mobilization of Ca2+ from an intracellular store in rat submandibular acini.
Increases in cytoplasmic free Ca2+ concentration in rat submandibular acini were observed in response to isoprenaline (10 microM), noradrenaline (10 microM) and carbamoylcholine (10 microM). Noradrenaline and carbamoylcholine responses were decreased to 27% and 33% respectively in the absence of extracellular Ca2+, suggesting a major requirement for Ca2+ entry. beta-Adrenergic stimulation elicited a small (35-40 nM) free Ca2+ rise, approx. 75% of which was mobilized from an intracellular store. Results suggest that this Ca2+ rise is a key event in the physiological triggering of mucin secretion by exocytosis.
Lloyd Mills
C
C
Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff, U.K.
Hallett
M B
MB
McPherson
M A
MA
Dormer
R L
RL
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D006706:Homeostasis; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008297:Male; D009077:Mucins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013363:Submandibular Gland / Q000187:drug effects / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D009077:Mucins; D011943:Receptors, Adrenergic, beta; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D002118:Calcium