Inhibition of gastric emptying and intestinal transit in anesthetized rats by a Tityus serrulatus scorpion toxin

Troncon, L E A; Santos, Armênio Aguiar dos; Garbacio, Viviane Ladeira; Secaf, Marie; Verceze, A.V.; Cunha-Melo, José Renan

doi:10.1590/s0100-879x2000000900010

Cited by 10 publications

(5 citation statements)

References 21 publications

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“…This method has been extensively employed due to its simplicity, ease-of-use, and accuracy (11). The present indexes of intestinal transit obtained from control rats were quite similar to those reported by others (10).…”

supporting

confidence: 86%

“…Fractional marker retention was calculated for each gut segment as a ratio between the counts obtained in this segment and the sum of counts of all gastrointestinal segments, including the gastroduodenal one. The data obtained for each individual segment were then multiplied by the number of the respective segment and summed up to calculate the geometric center of the marker distribution throughout the gastrointestinal tract (10).…”

mentioning

confidence: 99%

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Sildenafil delays the intestinal transit of a liquid meal in awake rats

Graça¹,

Macedo²,

Palheta³

et al. 2008

Braz J Med Biol Res

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Sildenafil slows down the gastric emptying of a liquid test meal in awake rats and inhibits the contractility of intestinal tissue strips. We studied the acute effects of sildenafil on in vivo intestinal transit in rats. Fasted, male albino rats (180-220 g, N = 44) were treated (0.2 mL, iv) with sildenafil (4 mg/kg) or vehicle (0.01 N HCl). Ten minutes later they were fed a liquid test meal ( 99m 99m 99m 99m 99m technetium-labeled saline) injected directly into the duodenum. Twenty, 30 or 40 min after feeding, the rats were killed and transit throughout the gastrointestinal tract was evaluated by progression of the radiotracer using the geometric center method. The effect of sildenafil on mean arterial pressure (MAP) was monitored in a separate group of rats (N = 14). Data (medians within interquartile ranges) were compared by the Mann-Whitney U-test. The location of the geometric center was significantly more distal in vehicle-treated than in sildenafil-treated rats at 20, 30, and 40 min after test meal instillation (3.3 (3.0-3.6) vs 2.9 (2.7-3.1); 3.8 (3.4-4.0) vs 2.9 (2.5-3.1), and 4.3 (3.9-4.5) vs 3.4 (3.2-3.7), respectively; P < 0.05). MAP was unchanged in vehicletreated rats but decreased by 25% (P < 0.05) within 10 min after sildenafil injection. In conclusion, besides transiently decreasing MAP, sildenafil delays the intestinal transit of a liquid test meal in awake rats. Sildenafil citrate belongs to a class of compounds called phosphodiesterase (PDE) inhibitors. PDEs constitute a family of enzymes that hydrolyze cyclic nucleotides (cyclic adenosine monophosphate and cyclic guanosine monophosphate, cGMP) and play a critical role in the modulation of the second messenger pathway (1). Sildenafil citrate is a selective PDE type 5 inhibitor widely used due to its therapeutic efficacy in human erectile dysfunction and pulmonary hypertension. It effectively blocks the PDE 5-mediated hydrolysis of cGMP inside vascular smooth muscle cells, relaxing the arterioles that supply the corpus cavernosum (2) and the lung parenchyma (3).Sildenafil increases the gastric resistance to injury by non-steroidal anti-inflammatory drugs (4), decreases the distal esophageal peristalsis (5), and inhibits the gastric emptying of test meals both in humans and rats (6,7), and decreases the contractility of isolated duodenal strips (8).Since the gastrointestinal transit rate results from a complex interplay between gastric tonus, distal stomach phasic activity and resistance and propulsion offered by the small intestine (9), we measured the effect of sildenafil on the small bowel intestinal transit of a liquid test meal in awake rats.

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supporting

confidence: 86%

mentioning

confidence: 99%

Sildenafil delays the intestinal transit of a liquid meal in awake rats

Graça¹,

Macedo²,

Palheta³

et al. 2008

Braz J Med Biol Res

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“…Some studies discuss the causes of emesis in scorpionism as the occurrence of early acute pancreatitis after envenomation in dogs and rats (30,37) presenting exocrine pancreatic hypersecretion (41). It is also associated with pancreatic dysfunction, and inhibition of the gastric emptying and intestinal transit (52) accompanied by increase in the gastrin seric levels (51).…”

Section: Discussionmentioning

confidence: 99%

Clinical and cardiovascular alterations produced by scorpion envenomation in dogs

Cordeiro¹,

Sakate²,

Fernandes³

et al. 2006

J. Venom. Anim. Toxins incl. Trop. Dis

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Scorpionism is a common problem that occurs in tropical and subtropical countries and assumes great medical-sanitary importance due to its fatal effect on sensitive individuals, being able to lead children and aged people to death. The envenomation lethal potential is responsible for the serious cardiopulmonary alterations the scorpion toxin produces in its victims. The present research evaluated the effects of Tityus serrulatus venom on dogs, using two distinct doses: a dose that simulates natural envenomation (0.4 mg/total dose), and an experimental dose (0.25 mg/kg). General clinical signs were observed at different moments after envenomation, and specific data related to the cardiopulmonary system were evaluated by systemic arterial pressure measurement, CK-MB enzymatic activity dosage, and radiographic, electrocardiographic and echocardiographic examinations. Results demonstrated that the scorpion venom, in experimental doses, was able to cause acute and reversible cardiac injury in few days, and, in the dose that simulated natural accident, it produced clinical signs of light envenomation, such as local pain, hyperesthesia, sialorrhea, vomiting, diarrhea, sneeze and prostration

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“…Fractional marker retention was calculated for each gut segment as a ratio between the counts obtained in one segment and the sum of counts in all segments. Values obtained for each individual segment were multiplied by the number of the respective segment and summed up to calculate the geometric center of marker distribution throughout the gut (28).…”

Section: Methodsmentioning

confidence: 99%

Evaluation of gastrointestinal motility in awake rats: a learning exercise for undergraduate biomedical students

Souza

Palheta

et al. 2009

Advances in Physiology Education

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Current medical curricula devote scarce time for practical activities on digestive physiology, despite frequent misconceptions about dyspepsia and dysmotility phenomena. Thus, we designed a hands-on activity followed by a small-group discussion on gut motility. Male awake rats were randomly submitted to insulin, control, or hypertonic protocols. Insulin and control rats were gavage fed with 5% glucose solution, whereas hypertonic-fed rats were gavage fed with 50% glucose solution. Insulin treatment was performed 30 min before a meal. All meals (1.5 ml) contained an equal mass of phenol red dye. After 10, 15, or 20 min of meal gavage, rats were euthanized. Each subset consisted of six to eight rats. Dye recovery in the stomach and proximal, middle, and distal small intestine was measured by spectrophotometry, a safe and reliable method that can be performed by minimally trained students. In a separate group of rats, we used the same protocols except that the test meal contained (99m)Tc as a marker. Compared with control, the hypertonic meal delayed gastric emptying and gastrointestinal transit, whereas insulinic hypoglycemia accelerated them. The session helped engage our undergraduate students in observing and analyzing gut motor behavior. In conclusion, the fractional dye retention test can be used as a teaching tool to strengthen the understanding of basic physiopathological features of gastrointestinal motility.

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Inhibition of gastric emptying and intestinal transit in anesthetized rats by a Tityus serrulatus scorpion toxin

Cited by 10 publications

References 21 publications

Sildenafil delays the intestinal transit of a liquid meal in awake rats

Sildenafil delays the intestinal transit of a liquid meal in awake rats

Clinical and cardiovascular alterations produced by scorpion envenomation in dogs

Evaluation of gastrointestinal motility in awake rats: a learning exercise for undergraduate biomedical students

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