Evidence for direct cellular protective effect of PL-10 substances (synthesized parts of body protection compound, BPC) and their specificity to gastric mucosal cells

The direct gastric mucosal cellular effect of four PL-10 substances (a synthesized part of human body protection compound, BPC containing 14 or 15 amino acids) was studied on freshly isolated rat gastric mucosal cells and on a mouse myeloma cell line (Sp2/0-Ag14) in an ethanol-induced cell injury model. The examined substances were not toxic for the cells. Two of them proved to be significantly protective against the direct cellular damaging effect of ethanol (PL 10.1.15AK-3 in 5 microg/ml dose and PL 10.1.AK14-2 dose-dependently, ED50=50 ng/ml) on gastric mucosal cells. This cytoprotective effect was failured on mouse myeloma cells. Based on these results a part of the in vivo protection induced by BPC seems to be a direct cellular protective effect to gastric mucosal cells.

Direct cellular effects of some mediators, hormones and growth factor-like agents on denervated (isolated) rat gastric mucosal cells

The brain-gut axis has an important role in the mechanism of gastric cytoprotection in vivo. The aim of this study was to evaluate the in vitro effect of protective agents without any central and peripheral innervation. A mixed population of rat gastric mucosal cells was isolated by the method of Nagy et al (Gastroenterology (1994) 77, 433-443). Cells were incubated for 60 min with cytoprotective drugs such as prostacyclin, histamine, pentagastrin and PL-10 substances (synthesized parts of BPC). At the end of this incubation cells were treated by 15% ethanol for 5 min. Cell viability was tested by trypan blue exclusion test and succinic dehydrogenase activity. The following results were obtained: 1) prostacyclin, histamine and pentagastrin had no direct cytoprotective effect on isolated cells; and 2) PL-10 substances significantly protected the cells against ethanol-induced cellular damage. This led to the following conclusions: 1) in the phenomenon of gastric cytoprotection only the growth factor-like agents have a direct cellular effect; and 2) the intact peripheral innervation is basically necessary for the development of mediators and hormone-induced gastric cytoprotection.

Some aspects of the effects of PL-10.1.AK-15 on the gastrointestinal tract

PL-10.1.AK-15 is an active fragment of a naturally occurring protein first isolated from human gastric juice. Among its other protective effects, PL-10.1.AK-15 has demonstrated a protective effect on the gastrointestinal tract. The aim of this study was to investigate the influence of PL-10.1.AK-15 on two functional parameters of gastrointestinal function: gastric acid secretion and gastrointestinal motility. Gastric acid secretion was assessed in male Wistar rats using a modified method of Shay, while gastrointestinal motility was assessed in male NMRI mice by charcoal propulsion. PL-10.1.AK-15 was given in three different doses (3, 10 and 100 micrograms/kg body weight) in accordance with the experimental protocol. The results of these experiments indicate that PL-10.1.AK-15 in the investigated doses had no influence on gastric acid secretion or gastrointestinal motility.

Gastric lesion development in normal and pylorus ligated rats after cervical vagotomy

The main purpose of this study was to further investigate the effects of vagotomy on gastric lesion development. In contrast to the usual subdiaphragmal vagotomy, a different vagotomy at the level of the trigonum caroticum was used both alone and in combination with pylorus ligation (done immediately after vagal transection). The animals were killed 15 min, 30 min, 1 h and 6 h following vagotomy. No damaging effects of sham-vagotomy, or obvious negative effects of cervical vagotomy were noted. Prominent lesions appeared after 1 h in rats subjected to cervical vagotomy and significantly increased lesions in the early period of pylorus ligation were noted. No further aggravation in pylorus ligated rats (even an apparent amelioration at 1-h interval) and no lesions in rats with cervical vagotomy in the latter period could be explained in terms of a lack of reactivity due to exhaustion preceding fatal outcome. Consistent with this, the rats subjected to cervical vagotomy died shortly after the 6-h period.