[The mechanism of inhibitory effect on parotid gland secretion with local injection of botulinum toxin type A in the rat].
OBJECTIVE
To determine the mechanism of inhibitory effect of botulinum toxin type A (BTX-A) on parotid gland secretion.


METHODS
Female Wistar rats (n = 18) were randomly divided into saline injection group (n = 6) and BTX-A injection group ( n = 12), respectively. 0.1 ml of saline was injected into left parotid gland and 2.5 U of BTX-A injected into right parotid gland. Rats were sacrificed at day 7, 12 and 35 post-injections respectively for morphology and vasoactive intestinal polypeptide (VIP) immunoreactivity of parotid gland.


RESULTS
Following BTX-A injection, some atrophic cells and reduction of number of VIP-immunoreactive (VIP-IR) fibers were found in gland and tube at day 7 (P < 0.05); at day 12, there was more obvious reduction of VIP-IR fibers around tube and vessels and atrophy of cells in BTX-A injection gland than saline injection gland (P < 0.001); at day 35, the glandular cells and VIP-IR fibers were similar to saline injection group.


CONCLUSIONS
BTX-A is effective for temporary elimination of hyperfunctioning sialorrhea via inhibition of VIP release which plays a key role in modulation of parotid glands secretion.
Wen
Wei-Dong
WD
Department of Anatomy, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730030, China.
Yuan
Fang
F
Hou
Yi-Ping
YP
D000818:Animals; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D005260:Female; D010306:Parotid Gland / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012798:Sialorrhea / Q000188:drug therapy; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D014660:Vasoactive Intestinal Peptide; D019274:Botulinum Toxins, Type A