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parallel secretion of secretory proteins and calcium by the rat parotid gland.
Author(s) -
Kanagasuntheram P,
Lim S C
Publication year - 1981
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1981.sp013637
Subject(s) - secretion , ribonuclease , parotid gland , secretory protein , amylase , medicine , stimulation , endocrinology , deoxyribonuclease , chemistry , calcium , submandibular gland , enzyme , biology , biochemistry , rna , dentistry , gene
1. The secretion of amylase, deoxyribonuclease, ribonuclease, protein and Ca2+ by the rat parotid gland in vitro was studied. 2. Isoproterenol and carbamoylcholine elicited a parallel discharge of amylase, deoxyribonuclease, ribonuclease and protein over a 40 min time period. 3. The composition of the secretion was independent of the secretogogue used for stimulation. When gland slices from the same animal were stimulated with isoproterenol, adrenaline, phenylephrine or carbamoylcholine, secretory enzymes and protein were secreted in constant proportions. 4. 45Ca injected intraperitoneally 16 h before stimulation with either isoproterenol or carbamoylcholine was released in parallel with amylase and protein. 5. The relative proportions of amylase, ribonuclease, deoxyribonuclease, protein and Ca present in isolated parotid gland secretory granules was identical to that of isoproterenol stimulated gland secretion. 6. It is concluded that the secretory proteins and Ca2+ are discharged in constant proportions by the rat parotid gland regardless of the mode of stimulation or the rate of secretion. The similarity in the composition of gland secretion and granule contents also suggests that enzymes and Ca2+ are released by exocytosis and not by diffusion across the apical plasma membrane.