Lea. Troncon et al., Inhibition of gastric emptying and intestinal transit in anesthetized ratsby a Tityus serrulatus scorpion toxin, BRAZ J MED, 33(9), 2000, pp. 1053-1058
Citations number
25
Categorie Soggetti
Medical Research General Topics
Journal title
BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH
The effects of a fraction (T1) of Tityus serrulatus scorpion venom prepared
by gel filtration on gastric emptying and small intestinal transit were in
vestigated in male Wistar rats, Fasted animals were anesthetized with ureth
ane, submitted to tracheal intubation and right jugular vein cannulation. S
corpion toxin (250 mu g/kg) or saline was injected iv and 1 h later a bolus
of saline (1.0 ml/100 g) labeled with (99m)technetium-phytate (10 MBq) was
administered by gavage, After 15 min, animals were sacrificed and the radi
oactivity remaining in the stomach was determined. Intestinal transit was e
valuated by instillation of a technetium-labeled saline bolus (1.0 mi) thro
ugh a cannula previously implanted in the duodenum. After 60 min, the progr
ession of the marker throughout 7 consecutive gut segments was estimated by
the geometric center method, Gastric retention of the liquid test, meal in
rats injected with scorpion toxin (median: 88%; range: 52-95%) was signifi
cantly higher (P<0.02) than in controls (54%; 21-76%), an effect which was
not modified by gastric secretion blockade with ranitidine. The progression
of the isotope marker throughout the small intestine was significantly slo
wer (P<0.05) in rats treated with toxin (1.2; 1.0-2.5) than in control anim
als (2.3; 1.0-3.2). Inhibition of both gastric emptying and intestinal tran
sit in rats injected with scorpion toxin suggests an increased resistance t
o aboral flow, which might be caused by abnormal neurotransmitter release o
r by the local effects of venom on smooth muscle cells.