Effects of amphetamine on salivary secretion.
Amphetamine induces xerogenic effects, but its mechanism of action and xerogenic potency are unknown. In the current in vivo study on the rat parotid gland, the effects of amphetamine on reflex-evoked and acetylcholine-evoked salivation were examined in the absence and presence of adrenergic and dopaminergic antagonists. Under anaesthesia, amphetamine increased the secretion of salivary fluid and the amount of protein therein in response to acetylcholine. Phentolamine abolished the increase in salivary flow and had no effect on the salivary protein concentration, whereas propranolol only reduced the salivary protein concentration. Reflex activation of the secretion evoked a well-maintained level of secretion that was reduced by amphetamine [50% inhibitory dose (ID(50)) 1.9 +/- 0.1 mg kg(-1) intravenously); the salivary protein concentration was increased in the presence of amphetamine. Phentolamine and haloperidol reduced the amphetamine-inhibitory effect on the reflex-evoked fluid response, whereas propranolol had no effect on the fluid response. The xerogenic effect of amphetamine is mainly exerted by central mechanisms involving alpha-adrenoceptors, while, indirectly, amphetamine causes secretion of protein by inducing the release of noradrenaline from glandular nerve terminals.
Götrick
Bengt
B
Department of Oral Diagnostics, Faculty of Odontology, Malmö University, Malmö, Sweden.
Giglio
Daniel
D
Tobin
Gunnar
G
D000109:Acetylcholine / Q000494:pharmacology; D018663:Adrenergic Agents / Q000494:pharmacology*; D018674:Adrenergic Antagonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D018678:Cholinergic Agents / Q000494:pharmacology; D019343:Citric Acid / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D005260:Female; D006220:Haloperidol / Q000494:pharmacology; D009411:Nerve Endings / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism; D010306:Parotid Gland / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects; D012463:Saliva / Q000187:drug effects* / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000032:analysis / Q000187:drug effects; D012472:Salivation / Q000187:drug effects; D012636:Secretory Rate / Q000187:drug effects
D018663:Adrenergic Agents; D018674:Adrenergic Antagonists; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D018678:Cholinergic Agents; D018492:Dopamine Antagonists; D012471:Salivary Proteins and Peptides; D019343:Citric Acid; D011433:Propranolol; D000661:Amphetamine; D006220:Haloperidol; D000109:Acetylcholine; D009638:Norepinephrine; D010646:Phentolamine