Effects of cevimeline on salivation and thirst in conscious rats.
OBJECTIVE
Intraperitoneal injection of a sialogogue, pilocarpine, at high concentrations induces salivation via peripheral pathways and thirst sensation via central pathways. In this study, we report that the effects of another sialagogue, cevimeline, on salivation and water intake in conscious rats differ from those of pilocarpine.


METHODS
We investigated that effects of peripherally and centrally injected cevimeline on parotid saliva flow rate and water intake in conscious rats. The results were compared with those of pilocarpine.


RESULTS
The intraperitoneal injection of cevimeline induced salivation from the parotid gland, but not water intake. In contrast, the intracerebroventricular injection of cevimeline induced water intake without salivation. The concentration of cevimeline needed to induce salivation by intraperitoneal injection was several 10 times that of pilocarpine, but that needed to induce water intake by intracerebroventricular injection was over a 1000 times greater.


CONCLUSIONS
The finding that intraperitoneally injected cevimeline induces salivation without inducing water intake, suggests that the effects on the thirst center in the brain are weaker than those of pilocarpine.
Sato
Nao
N
Department of Biosciences, Kyushu Dental College, 2-6-1 Manazuru, Fukuoka 803-8580, Japan.
Ono
Kentaro
K
Haga
Kensuke
K
Yokota
Makoto
M
Inenaga
Kiyotoshi
K
D000818:Animals; D002490:Central Nervous System / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D004334:Drug Administration Schedule; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D018721:Muscarinic Agonists / Q000008:administration & dosage*; D010306:Parotid Gland / Q000187:drug effects / Q000502:physiology; D011812:Quinuclidines / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012472:Salivation / Q000187:drug effects*; D013876:Thiophenes / Q000008:administration & dosage*; D013894:Thirst / Q000187:drug effects*
D018721:Muscarinic Agonists; D011812:Quinuclidines; D013876:Thiophenes; C059240:cevimeline