Paper Title
The Influence of Bisphenol a on Nerve Fibers Immunoreactive to Cocaine- and Amphetamine-Regulated Transcript (CART) in Porcine Jejunum

Abstract
Cocaine- and amphetamine-regulated transcript (CART) is a peptide regulating the motility of the gastrointestinal tract. It is present in sundry parts of the nervous system, especially in thestructures within the enteric nervous system (ENS)located in the wall of the digestive tract. Its physiological role is still poorly understood, but it is known that it may have neuroprotective functions in the ENS. Bisphenol A (BPA) belongs to the group of phenols and it is used in production of, e.g. food containers and dental floss. It is able to penetrate the food and affect living organisms negatively. The aim of this study was to reveal the changes in CART + nerve fibers in the mucosal/submucosal and circular muscle layer of jejunum under the influence of BPA. Jejunal fragments were collected from 10 sexually immature gilts divided into a control group (group A, n = 5) - receiving empty gelatin capsules, and a research group (group B, n = 5) – receiving capsules with BPA in dose 0.05 mg/kg b. w./day;for 28 days during morning foraging.Fragments of jejunum were undergone single-staining immunofluorescence method with the use of anti-CART antibodies. The number of CART + nerve fibers was determined by counting them in 50 fields of view of the microscope (0.1 mm²) / animal. The data were pooled and presented as mean ± SEM. BPA administration resulted in a statistically significant (p ≤ 0.001) decrease in the number of CART + fibers - from 11.02 ± 0.11% to 9.14 ± 0.07% in submucosal/mucosal layer, and from 25.10 ± 0.25% to 18.25 ± 0.05% in circular muscle layer of jejunum. The results indicate that the short-term administration of bisphenol A causes changes inCART+ nerve fibers and their number decline may suggest a neurodegenerative effect of BPA on jejunal part of ENS. However, the BPA influence on the enteric neurons requires further study. Publication supported by KNOW (Leading National Research Centre) Scientific Consortium "Healthy Animal - Safe Food", decision of Ministry of Science and Higher Education No. 05-1/KNOW2/2015.