6369803287

The influence of naproxen supplementation on nitrergic neurons In the enteric newous system (ENS) in the porcine duodenum

Czajkowska Marta

Department of Oinkal Physiology, Faculty of Veterinary Medicine, Uniwersity of Warmia and Mazury in Olsztyn

Due to numerous indications and high avaflabikty. non-steroidal anti-inflammatory drugs (NSAlDs) bełoog to the most frequentty prescribed and used drugs in the wortd. However. long-term treatment and inappropriate use of NSAlDs may lead to damage to the gastrointestinal tract The enteric nervous system (ENS) is an iritegrated network off neurons and głia within the boweł wali that Controls most aspects of bowet funcbon. Enteric neurons are characterized by considerable plasticity. and the appearance of a pathotogical factor results in a change in the synthesis of neurotransmitters. Nitric oxide (NO) produced by the neuronal nitric oxide synthase (nNOS) enzyme represents an important regulatory neurotransmitter. Aberrant NO signaMing contributes significandy towards enteric dtsease by attering gut motility, vascular tonę. blood suppły. mucosal ba mer function. secretions and immunity. The aim of the study was to determine the effect of inftammation ca used by high naproxen supplementation on nNOS expressionin enteric duodenal neurons in domestic pigs.

Materiał and methods

The study was carried out on eight immature pigs of the Pietram x Duroc race (approorimateły 20 kg of body weight). The animals were dńrided into two groups - a control (C group) and an experimental group (N group). Group C (n=4) was consisted of animals which recewed empty gełabne capsules Group N (n=4) was composed of pigs which naproxen were given orały for 4 weeks. approximateły 1 h before feeding. After this time. animals from both groups were euthanized. Then. frozen sections (14 pm thackness) were prepared from the collected materia! and subyected to double śmmunofluorescence staining. Anttbodws against the neuronal marker PGP 9.5 and against the neuronal isofbnm of nitric aaaóe synthase were used as primary antibodies. The secondary antibodies - Alexa Fluor 488 and 546 - were also used for staining. Anałysis of the sections was performed using an Olympus BX51 fluorescence microscope eąuipped with a XM10 monochrome camera.

Results and conclusion

Anałysis of the results obtained with a fluorescence microscope showed sjgnrficant increase in the number of nNOS immunoreactive outer (from 8.40% in C group to 12.97% in N group) and mer submucosal neurons (from 6.39% in C group to 11.50% in N group) and a smaller increase in the number of nNOS positive neurons in the myenteric gangiia (from 18.50% in C group to 20.26% in N group) of the porem duodenum.

The obtained results suggest that inftammation caused by the adrranistrabon of high doses of napronen inereases the expressaon of nNOS in the duodenal neurons in domestic pigs Incrsased synthesis of this enzyme may suggest the contribution of nitric oxide to thn devełopment of the local inflammatory proces i or the »nvołvement of nitrergic neurons in local r»paif

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This study was supported by the National Science Centrę

(grant no. 2018/29/N/NZ4/00348).    _m    ^

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