Some amino acids been known to influence gastric emptying. Thus we have evaluated the effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying.Gastric emptying was evaluated in rats after feeding with Racol (nutrient formulae) containing [1-(13)C] acetic acid. Using a breath test, the content of (13)CO2 in their expired air was measured by infrared analyzers. Rats were orally administered with test amino acids, while control rats were administered orally with distilled water.The expired (13)CO2 content in the expired air increased with time, peaked after about 30 min and decreased thereafter. Among the amino acids having an alkyl chain, L-serine, L-alanine and L-glycine, significantly decreased the (13)CO2 content and Cmax, and delayed Tmax, suggesting inhibition and delay of gastric emptying. AUC(120min) values of L-alanine and L-glycine also decreased significantly. L-Threonine significantly decreased (13)CO2 content and delayed Tmax, but had no influence on Cmax and AUC(120min) values, suggesting a delay of gastric emptying. L-Isoleucine and L-leucine and L-valine significantly decreased (13)CO2 content, suggesting inhibition of the gastric emptying, but Cmax, Tmax and AUC(120min) values were not significantly affected.The results show that the amino acids used in the present study had different effects on gastric emptying. Moreover, it was found that inhibition and delay of gastric emptying were clearly classifiable by analyzing the change in (13)CO2 content of the expired air and the Cmax, Tmax and AUC(120min) values.
Increased levels of lactate, an end-product of glycolysis, have been proposed as a potential surrogate marker for metabolic changes during neuronal excitation. These changes in lactate levels can result in decreased brain pH, which has been implicated in patients with various neuropsychiatric disorders. We previously demonstrated that such alterations are commonly observed in five mouse models of schizophrenia, bipolar disorder, and autism, suggesting a shared endophenotype among these disorders rather than mere artifacts due to medications or agonal state. However, there is still limited research on this phenomenon in animal models, leaving its generality across other disease animal models uncertain. Moreover, the association between changes in brain lactate levels and specific behavioral abnormalities remains unclear. To address these gaps, the International Brain pH Project Consortium investigated brain pH and lactate levels in 109 strains/conditions of 2,294 animals with genetic and other experimental manipulations relevant to neuropsychiatric disorders. Systematic analysis revealed that decreased brain pH and increased lactate levels were common features observed in multiple models of depression, epilepsy, Alzheimer's disease, and some additional schizophrenia models. While certain autism models also exhibited decreased pH and increased lactate levels, others showed the opposite pattern, potentially reflecting subpopulations within the autism spectrum. Furthermore, utilizing large-scale behavioral test battery, a multivariate cross-validated prediction analysis demonstrated that poor working memory performance was predominantly associated with increased brain lactate levels. Importantly, this association was confirmed in an independent cohort of animal models. Collectively, these findings suggest that altered brain pH and lactate levels, which could be attributed to dysregulated excitation/inhibition balance, may serve as transdiagnostic endophenotypes of debilitating neuropsychiatric disorders characterized by cognitive impairment, irrespective of their beneficial or detrimental nature.
Background This study aimed to evaluate the effects of the position of an acetic acid-induced gastric ulcer and the effects of prokinetic drugs on gastric emptying. Materials and Methods Male Sprague-Dawley rats were used in this study. Acetic acid ulcers were induced either in the region between the fundus and pylorus on the anterior wall of the stomach or in the glandular region on the greater curvature of the stomach to determine whether there were regional differences in the effect of the ulcers. Gastric emptying was evaluated with a breath test using [1-13C] acetic acid. In addition, the effects of the prokinetic drugs, metoclopramide and mosapride, on gastric emptying were also evaluated. Results Acetic acid induced ulcers in the region between the fundus and pylorus on the anterior wall of the stomach significantly delayed gastric emptying as compared with control rats, but not the acetic acid induced ulcers in the glandular region on the greater curvature of the stomach. Metoclopramide and mosapride did not improve the delayed gastric emptying even at doses that enhanced gastric emptying in normal rats. Conclusion These findings show that gastric emptying is influenced by the position of the ulcer and the region between the fundus and pylorus on the anterior wall plays an important role in gastric emptying. Moreover, it was found that metoclopramide and mosapride do not improve the delayed gastric emptying caused by acetic acid ulcers induced on the anterior wall in the region between the fundus and pylorus.
Purpose: To evaluate the morphological changes in retinal microstructures following modified photodynamic therapy (PDT) for chronic central serous chorioretinopathy. Subjects and methods: Retrospective study of 21 consecutive eyes (age, 59±8.0 years [mean ± SD]) of 21 patients with chronic central serous chorioretinopathy. Inner foveal thickness (the distance between the internal limiting membrane and external limiting membrane), photoreceptor outer segment (PROS) length at the point without serous retinal detachment and choroidal thickness were assessed with enhanced depth imaging optical coherence tomography before treatment and at 1, 3 and 6 months after modified PDT. Results: Six eyes had half-dose and 15 eyes had half-fluence PDT. PROS length within the irradiated area was significantly decreased by 3.9% at 1 month compared with that before modified PDT (43.5±5.72 and 40.5±7.53, P =0.020 [paired t -test]) and returned to baseline length at 3 and 6 months (43.0±5.42 and 43.5±4.33 µm [mean ± SD]; P =0.53 and 1.00 [paired t -test]). PROS length of the nonirradiated area at 1, 3 and 6 months after modified PDT did not significantly differ from that before PDT (41.8±6.35, 41.4±5.33, 41.9±4.67 and 42.3±4.26 µm [mean ± SD]; P =0.66, 0.90 and 0.60, respectively [paired t -test]). There was no significant change in inner foveal thickness during the observation period. At all time points, choroidal thickness was significantly thinner than it was before PDT ( P <0.001, paired t -test). Conclusion: Modified PDT may cause mild temporary microstructural changes. Keywords: photodynamic therapy, photoreceptor outer segment length, chronic central serous chorioretinopathy, inner foveal thickness, choriocapillaris
