The effects of acute and chronic lithium treatment on rat submandibular salivation.
OBJECTIVE
Acute and chronic actions of lithium on salivation induced by agonists associated with receptor-linked hydrolysis of membrane inositol phospholipids (carbachol and phenylephrine) and by agonist linked to activation of adenylate cyclase (isoproterenol) were investigated.


METHODS
In anaesthetized rats, submandibular salivation induced by intravenous injection of carbachol, phenylephrine and isoproterenol, was measured and expressed as volume of fluid (microl) elicited per 100 mg wet weight of each gland per minute. The experiments were repeated after acute and chronic treatment of lithium (7 mg kg(-1)). The results were analysed with unpaired t-test.


RESULTS
Chronic, but not acute lithium treatment significantly decreases carbachol- and phenylephrine-induced salivation while isoproterenol-induced salivation was not changed neither after acute nor after chronic administration of lithium.


CONCLUSIONS
The results suggest that hyposalivation during chronic lithium therapy could be mediated by alterations in the phosphatidylinositol cycle and a consequent lack of inositol after agonist stimulation.
Popović
J
J
Department of Pharmacology, Faculty of Stomatology, University of Belgrade, Belgrade, Serbia & Montenegro.
Krsljak
E
E
Grbović
L
L
Stojić
D
D
D000208:Acute Disease; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000493:pharmacokinetics; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D002908:Chronic Disease; D004305:Dose-Response Relationship, Drug; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012472:Salivation / Q000187:drug effects*; D013363:Submandibular Gland / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D018679:Cholinergic Agonists; D010716:Phosphatidylinositols; D010656:Phenylephrine; D002217:Carbachol; D008094:Lithium; D007545:Isoproterenol