Non-invasive biomagnetic assessment of gastrointestinal motility in a loperamide-induced constipation model

Constipation is a disorder of the gastrointestinal (GI) and some of the main etiological mechanisms are directly related to changes in GI physiology. The capacity to carry out paired assessments and measure GI parameters under the influence of constipation is a relevant point in selecting a suitable methodology. We aimed to perform a non-invasive investigation of gastrointestinal motility in constipated rats using the alternating current biosusceptometry system (ACB). The animals were split into two groups: the pre-induction stage (CONTROL) and post-induction loperamide stage (LOP). We assessed GI motility parameters using the ACB system. Colon morphometric and immunohistochemical analyses were performed for biomarkers (C-kit) for interstitial cells of Cajal (ICC). Our results showed a significant increase in gastrointestinal transit in the LOP group in addition to a reduction in the dominant frequency of gastric contraction and an arrhythmic profile. A change in colonic contractility profiles was observed, indicating colonic dysmotility in the LOP group. We found a reduction in the number of biomarkers for intestinal cells of Cajal (ICC) in the LOP group. The ACB system can evaluate transit irregularities and their degrees of severity, while also supporting research into novel, safer, and more efficient treatments for constipation.

BALB/c and C57BL/6 mouse strains influence gastric function outcomes with administration of cisplatin and dexamethasone

Abstract Our aim was to evaluate the effects of cisplatin and dexamethasone alone and combined on gastric contractility and histomorphometry of BALB/c and C57BL/6 mice. BALB/c and C57BL/6 male mice (8-week-old) were randomly separated into: Control; Cisplatin (7.5 mg/Kg); Dexamethasone (2.0 mg/Kg); and Dexamethasone plus Cisplatin (2.0 mg/Kg of dexamethasone 1-hour prior to 7.5 mg/Kg of cisplatin). Drugs were administered intraperitoneally for three days. Body weight and food intake were evaluated on 2nd day. Alternating Current Biosusceptometry technique was employed to measure gastric contractions on 3rd day. Afterward, mice were killed for gastric histomorphometric analysis. Cisplatin decreased food intake and caused bradygastria in BALB/c mice; however, the amplitude of gastric contractions decreased in both BALB/c and C57BL/6. Dexamethasone and cisplatin combined restored the gastric frequency and food intake only in BALB/c, but drug combination reduced the gastric amplitude of contractions in both strains. Dexamethasone alone increased gastric mucosa thickness in C57BL/6 and decreased muscular thickness in BALB/c. In conclusion, the mouse strains presented differences in acute effects of cisplatin and dexamethasone alone and combined on gastric function. This reinforces the importance of choosing the appropriate mouse strain for studying the acute effects of drugs on the gastrointestinal tract.