Secretory effects of 5-hydroxytryptamine following neonatal sympathectomy in rat parotid gland.
Unilateral sympathetic denervation of rat parotid glands was performed within 4 h after birth. Nine weeks later the glands were used for in-vitro studies of amylase secretion, and 86Rb+ was used as a marker for potassium efflux. The non-denervated contralateral glands served as controls. The tissue concentrations of 5-hydroxytryptamine and its metabolite 5-hydroxyindole acetic acid were also measured. 5-Hydroxytryptamine caused a significant dose-dependent increase in amylase secretion, which was inhibited by methysergide. There was no difference between controls and denervated glands. 5-Hydroxytryptamine was without effect on potassium efflux from either denervated or control glands. The sympathectomy caused increased levels of 5-hydroxytryptamine and 5-hydroxyindole acetic acid as compared with contralateral controls. The results suggest that 5-hydroxytryptamine influences the two main secretory processes in rat parotid gland differently. A significant amylase discharge was seen following 5-hydroxytryptamine stimulation, whereas no effect was seen on 86Rb+ efflux. Although it is also proposed that there are no 5-hydroxytryptamine-associated nerves in the superior cervical ganglion innervating parotid tissue, it seems that there is a complex connection between the sympathetic pathway and the serotoninergic system.
Department of Histology, University of Umeå, Sweden.
R
R
Henriksson
S
S
Sundström
A
A
Danielsson
S
S
Hellström
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D008784:Methysergide / Q000494:pharmacology; D010306:Parotid Gland / Q000294:innervation / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*; D013562:Sympathectomy
D012701:Serotonin; D000681:Amylases; D011188:Potassium; D008784:Methysergide