Autonomic control of protein production by the parotid gland of the sheep.
Auton Neurosci
; 103(1-2): 38-49, 2003 Jan 31.
Article
em En
| MEDLINE
| ID: mdl-12531397
ABSTRACT
The role of adrenoceptors in the control of parotid salivary function has been investigated in anaesthetized sheep. The enhancement of parotid protein output that occurs when the parasympathetic and sympathetic innervations to the gland are stimulated simultaneously in bursts at a low frequency (20 Hz for 1 s at 10-s intervals) was effectively abolished by pretreatment with propranolol (> or = 1.0 mg kg(-1), i.v., P < 0.001), without a comparable reduction in the flow of saliva or in the output of sodium or potassium. Secretion of protein was similarly augmented by simultaneous stimulation of the sympathetic innervation and an intracarotid infusion of acetylcholine (0.4-0.6 microg min(-1) g gland(-1)). This effect was also abolished by pretreatment with propranolol. Pretreatment with phentolamine (>1.0 mg kg(-1), i.v.) had no effect on the output of protein that occurred during combined stimulation of the parasympathetic and sympathetic innervations but increased the flow of saliva and the output of electrolytes. Stimulation of the parasympathetic innervation to the parotid gland caused a substantial fall in vascular resistance, which was reduced by the administration of atropine (0.5 mg kg(-1)). Stimulation of the sympathetic innervation caused a substantial rise in parotid vascular resistance in atropinized sheep. This effect was greater during continuous stimulation than during intermittent stimulation and enhanced by pretreatment with propranolol. It was virtually eliminated by pretreatment with phentolamine. It is concluded that the enhancement of protein output from the ovine parotid gland, that occurs during combined stimulation of the parasympathetic and sympathetic innervations at relatively low frequencies, depends upon interaction between cholinergic muscarinic and beta-adrenergic receptors. The vasoconstriction that occurs during sympathetic stimulation alone can be accounted for by activation of alpha-adrenoceptors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glândula Parótida
/
Saliva
/
Sistema Nervoso Autônomo
/
Proteínas
/
Receptores Adrenérgicos alfa
/
Receptores Adrenérgicos beta
/
Receptores Muscarínicos
Limite:
Animals
Idioma:
En
Revista:
Auton Neurosci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Reino Unido