Adrenergic and cholinergic regulation of phospholipid release in sublingual salivary gland in vitro.
1. The role of adrenergic and cholinergic mediators in the regulation of salivary phospholipid secretion was investigated using rat sublingual acinar cells maintained in the presence of [3H]choline. 2. The release of [3H]choline containing phospholipids was enhanced by beta-adrenergic agonist, isoproterenol to a greater extent than the cholinergic agonist, pilocarpine. 3. The effect of isoproterenol on phospholipid release was observed even after 5 min and by 30 min a 1.7-fold increase in secretion occurred, whereas pilocarpine evoked 1.2-fold increase by 30 min with no discernible effect in 5 min. The isoproterenol effect was blocked by alprenolol, and an inhibition of pilocarpine effect was observed with atropine. 4. In the absence of mediators, 82% of secreted labeled phospholipids were represented by phosphatidylcholine (PC), 4.3% by lysophosphatidylcholine (LPC) and 12.1% by sphingomyeline (Sph), those secreted in the presence of isoproterenol showed significantly lower (37%) content of LPC, while those secreted in response to pilocarpine were substantially richer in LPC (2.5 times) and Sph (27%), and contained less (17%) PC. 5. The results provide first evidence for the involvement of adrenergic and cholinergic mediators in the regulation of salivary phospholipid secretion.
Slomiany
B L
BL
Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark 07103-2400.
Sengupta
S
S
Fekete
Z
Z
Murty
V L
VL
Slomiany
A
A
D000526:Alprenolol / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002794:Choline / Q000378:metabolism; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D010743:Phospholipids / Q000378:metabolism*; D010862:Pilocarpine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012469:Salivary Glands / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000502:physiology*
D010743:Phospholipids; D011943:Receptors, Adrenergic, beta; D010862:Pilocarpine; D001285:Atropine; D000526:Alprenolol; D007545:Isoproterenol; D002794:Choline