Increased gastric emptying induced by Helicobacter heilmannii type 1 infection in rats

Abstract

The association between Helicobacter pylori infection and gastric motility abnormalities is still controversial, partly because of the lack of an appropriate animal model. H. heilmannii type 1 (Hh1), a spiral bacterium that infects the stomach of both man and pigs, easily colonises and induces an in¯ammatory response in the gastric mucosa of rodents. For these reasons, the present study investigated the relationship between gastric motility in rats experimentally infected with Hh1 and correlated the results with serum gastrin and gastric somatostatin concentrations, as these hormones seem to be involved in gastric motility. Ten rats were inoculated with gastric mucus from an Hh1-positive pig and 10 animals with gastric mucus from an Hh1-negative pig (control group). After 56 days, gastric emptying was studied in vivo by scintigraphy. The animals were then killed, blood samples were collected for serum gastrin measurement, strips of the gastric wall were obtained for an in-vitro motor study and fragments of the gastric antrum were obtained for somatostatin content evaluation, Hh1 diagnosis and histological study. There was a signi®cant increase in gastric emptying in the test group compared with the controls as demonstrated by the in-vivo and in-vitro studies. Serum gastrin levels were signi®cantly higher and somatostatin levels were lower in the test group than in the controls. In addition, infected animals showed evidence of gastritis on histological examination. Gastric motility is altered in rats infected with Hh1, a fact possibly related to concurrent abnormalities of gastrin and somatostatin secretion.

<a name="home"></a>The role of IFN-gamma and IL-4 in gastric mucosa inflammation associated with Helicobacter heilmannii type 1 infection

“…Mucus positive for H. heilmannii showed a rapidly positive result for the urease test, presented many tightly spiraled bacteria in carbolfuchsin-stained smears and was PCR positive for H. heilmannii type 1 (24). Bacterial viability was assayed by checking motility by phase contrast microscopy.…”

“…DNA from mucosal fragments was extracted with a QIAamp DNA minikit (Qiagen GmbH, Hilden, Germany) and 16S rRNA gene was amplified by nested PCR using primer sets specific for Helicobacter genus according to Oliveira et al (28). For the detection of H. heilmannii type 1 species, 16S rRNA cistrons were amplified with primers chosen on the basis of the 16S rRNA gene sequence of H. heilmannii type 1 as described by Duval-Araujo et al (24).…”

“…In the pig, the infection is associated not only with gastritis, but also with pre-ulcerous lesions and ulcer of the pars esophagea (20,21). Although the bacterium has not been cultured in vitro, oral inoculation of mice and rats with H. heilmanniipositive mucus of pig stomach results in 100% gastric infection that also leads to chronic gastritis (22)(23)(24). Based on comparative 16S rDNA data, the sequence of the spiral porcine bacterium was shown to be identical to that of H. heilmannii type 1 (21,25).…”

Influence of Helicobacter pylori infection on in vitro responsiveness of gastric fundus to agonists and to stimulation of enteric nerves in Mongolian gerbils

“…On the other hand, it was reported that gastric motility was altered in rats infected with Helicobacter heilmannii type 1, possibly due to concurrent abnormalities of gastrin and somatostatin secre- tion, and in-vitro maximal gastric contraction was greater in H. heilmannii type 1-infected rats than in the controls. 29 However, these data could not exclude the possible involvement of the altered responses of inflamed tissue to inhibitory neural stimulation in conditions of impaired motility in their experiments, and, further, gastric NANC relaxation had never been evaluated in a H. pylori-infected model. Thus, we assessed the effect of H. pylori infection on in-vitro enteric neural transmission and smooth muscle function by analyzing the responses to EFS and some agents.…”

Gastric Emptying is Altered with the Presence of Gastritis

“…Many of these gastrointestinal disturbances and symptoms of stomach pain, nausea and bloating, which are common with H. pylori infection and gastritis, suggest that there may also be an association with altered gastric emptying. Gastric emptying rates in patients with H. pylori induced gastritis has been previously investigated [3][4][5][6][7][8][9], but the findings were contradictory. Thus, there are no definite conclusions as to whether H. pylori is able to influence the motility of the upper gastrointestinal tract.…”