Immunohistochemical localization of pancreatic spasmolytic polypeptide (PSP) in the pig

Abstract

Pancreatic spasmolytic polypeptide (PSP) is a peptide that is isolated from the porcine pancreas and that affects intestinal motility and growth of intestinal tumour cells in vitro. The peptide was recently demonstrated to be present in large amounts in pancreatic juice. The cellular origin of the peptide, however, is largely unclarified and the localization was therefore studied of PSP in pigs using immunohistochemistry. Positive immunoreactions were seen in the pancreas, the stomach, the duodenum, the jejunum and the ileum. In the pancreas, the PSP immunoreaction was seen in all acinar cells; no immunoreaction was seen in the endocrine islets. In the stomach, it was localized to the mucous cells of the glands in the cardiac gland region, the corpus and the pylorus. In the duodenum a strong immunoreaction was present in Brunner's glands and in the cells of their excretory ducts. In the jejunum and ileum, PSP immunoreactivity was seen in some of the cells in the epithelium of the crypts of Lieberkühn. A peptide chromatographically identical to highly purified PSP was identified in pancreas and stomach extracts. Thus epithelial cells in all parts of the stomach and small intestine contribute to the supply of PSP to the gut lumen.

Intestinal Expression of TFF and Related Genes During Postnatal Development in a Piglet Probiotic Trial

“…In pigs TFF2 is apparently expressed on the entire luminal surface of the gastrointestinal tract at rather high concentrations [25]. Expression of TFF2 in vivo has been documented in various organisms, each having a unique tissue specific pattern.…”

“…Our results in porcine gastric tissue, however, are concordant to high protein expression of TFF2 in the stomach reported in other species. In a previous study with pigs by Rasmussen et al, immunostaining revealed TFF2 expression in pancreas, in mucous cells of the glands of the stomach, in Brunner's glands of the duodenum, and in epithelial cells of the crypts of Lieberkühn in the jejunum and ileum, but not in duodenal goblet cells [25]. Localization of TFF2 in this study is in agreement with the studies by Rasmussen et al in terms that goblet cells of the intestinal epithelium did not express TFF2.…”

“…In previous studies, porcine TFF2 expression and localization was observed by means of immunohistology [25], however, TFF2 expression has not been quantified in the context of postnatal intestinal development and the weaning period. In respect to their beneficial functions during gastrointestinal healing, TFFs represent potential candidates to act as luminal regulators in response to the high microbial and nutritional challenges arising during intestinal postnatal development and weaning.…”

TFF2, a MUC6-binding lectin stabilizing the gastric mucus barrier and more (Review)

“…Interestingly, porcine pancreatic TFF2 forms non-covalently linked dimers in the solid phase (9,11) as well as in solution (12); the latter being unusually resistant even to boiling SDS (12). TFF2 is typically co-secreted with the mucin MUC6 from gastric fundic and antral glands (mucous neck and antral gland cells, respectively) as well as duodenal Brunner's glands (13)(14)(15)(16)(17) and represents a characteristic constituent of the gastroduodenal mucus (18). Of special note, in the gastric fundic glands TFF2 mRNA and protein do not co-localize.…”

“…TFF2 also appears as a constituent of the gastric juice with dramatic diurnal variations (22). In the pig, in contrast to human, TFF2 is also abundantly secreted from exocrine pancreatic glands (acinar cells) (14). Furthermore, TFF2 is expressed in salivary glands (21,23).…”