Piotr Rekowski

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The sequence-dependent, acid- or base-catalysed aspartimide formation is one of the most serious side reactions in solid-phase synthesis of peptides containing aspartic acid. In the present work, we investigated the susceptibility of 4-(N-[1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutyl]amino)benzyl (Dmab), an aspartic acid beta-carboxy side-chain(More)
Inhibitory effect of galanin on basal and secretagogs-stimulated gastric acid secretion was investigated in urethane-anesthetized rats. A rat stomach was mounted in an ex-vivo chamber, perfused with saline, and either gastric acid or alkaline secretion was determined by titrating the perfusate. Gastric mucosal blood flow (GMBF) was measured by a laser(More)
Galanin (GAL), a 29-amino-acid-residue neuropeptide, modulates gastric smooth muscles activity by interacting with specific receptors. However due to the lack of specific antagonists in the gastrointestinal (GI) tract the actual level of GAL involvement in GI motility remains largely unknown. In our studies we have performed structure-activity relationship(More)
Cell-penetrating peptides (CPP) are a family of peptides able to penetrate the cell membrane. This group of compounds has attracted consideration as potential therapeutic tools for the delivery of various substances into cells. Here, we investigated possible interactions between several CPP synthesized in our laboratory and the vascular action of(More)
The effects of heme oxygenase (HO) inhibitors, zinc-protoporphyrin-IX (ZnPP-IX), and tin protoporphyrin-IX (SnPP-IX) and their interactions with L-arginine/nitric oxide synthase (NOS) and cyclooxygenase (COX) pathways were investigated in postoperative ileus in rats. Intestinal transit was measured as Evans blue migration after skin incision, laparotomy or(More)
Porcine galanin (pGAL), its 15-amino-acid-residue fragment and five new analogues modified in positions 4, 6 or 14 were tested for their effects on glucose-induced insulin secretion from isolated rat pancreatic islets of Langerhans. In vitro insulin secretion was studied during static incubation. All peptides were tested at two concentrations: 100 nM and 1(More)
Galanin (GAL) is a 29-amino-acid residue peptide originally isolated from porcine upper small intestine. GAL exhibits various physiological activities, such as effects on hormones release, smooth muscles contractions, gastric acid secretion, neurons degeneration and feeding. One of the biological actions of GAL is the inhibition of insulin secretion from(More)
Aspartimide (Asi) formation is one of the most serious side reactions that can occur both during solid phase synthesis and storage of peptides containing aspartic acid. Although numerous studies on the mechanism of Asi formation conducted so far, the problem still remains unresolved and relatively little is known about the impact of this side reaction on(More)
Behavioral effect of galanin and its fragments, galanin1–15 and galanin16–29 (200 ng, 1 and 5 μg), after intracerebroventricular (i.c.v.) administration was studied in rats. The number of crossings and pippings and the time of locomotion (an open field test) showed a similar sedative action of galanin and galanin16–29, with no significant effect of(More)
A new peptide nucleic acid (PNA) mediated QPCR technique for the detection and quantification of the Multiple Sclerosis-Associated Retrovirus (MSRV) belonging to the human endogenous retrovirus-W (HERV-W) family has been developed. The assay utilizes a PNA probe which is fully complementary to the ERVWE1 sequence, another member of the HERV-W family which(More)