Disease relevance of MLN

• In contrast immunization via BALT (respiratory infection with PRCV) elicited systemic type responses (high numbers of IgG ASC in the BLN), but few ASC and low LPA responses in the gut LP or MLN and induced only partial protection against enteric TGEV challenge [1].
• The origin and fall of plasma motilin during Escherichia coli endotoxin shock in pigs [2].

Psychiatry related information on MLN

• Physiological studies, however, have suggested central roles for motilin in a variety of CNS (feeding behavior, bladder control, cerebral and brain stem modulation, pituitary growth hormone release) and gastrointestinal (gastric emptying, intestinal motility) functions [3].
• Synthesis of the hexadecapeptide corresponding to positions 1 through 16 of porcine motilin, a gastric motor activity stimulating polypeptide [4].

High impact information on MLN

• These results suggest that pancreatic polypeptide, but not somatostatin, may have a regulatory function on the rhythmicity of the migrating myoelectric complex in the dog and pig and that motilin does not control the occurrence of duodenal migrating myoelectric complex in the pig [5].
• Nucleotide sequence analysis predicts a precursor protein of 119 amino acids including a signal peptide in direct linkage with the 22 amino acid sequence for motilin, and a 70 amino acid peptide of unknown function [6].
• Cloned cDNAs encoding the precursor protein for motilin and a novel peptide, motilin-associated peptide, were isolated from a library derived from porcine intestinal mucosa mRNA [6].
• Letter: Diphenyl phosphorazidate (DPPA) and diethyl phosphorocyanidate (DEPC). Two new reagents for solid-phase peptide synthesis and their application to the synthesis of porcine motilin [7].
• Three-dimensional structure and position of porcine motilin in sodium dodecyl sulfate micelles determined by 1H NMR [8].

Biological context of MLN

• IL-10 gene expression in MLN draining the colon of pigs experimentally infected with T. suis increased 10-20 fold at day 35 compared to control pigs [9].
• Results indicated that the septic animals that received the high protein diet had more bacterial translocation, as indexed by higher radionuclide counts in the MLN, liver, lung and blood [10].
• Motilin and erythromycin-A share a common binding site in the third transmembrane segment of the motilin receptor [11].
• Several lines of evidence suggest that motilin and ghrelin are involved in the control of gastrointestinal motility by the activation of receptors on enteric neurons [12].
• Motilin increases food intake in mice [13].

Anatomical context of MLN

• Virulent TGEV exposure resulted in increased percentages of T cell subsets, especially in the lamina propria and MLN, mucosa-associated lymphoid tissues in proximity to the primary replication site of TGEV in the small intestine [14].
• Primary inoculation of 11-day-old pigs with PRCV induced moderate, transient virus-specific lymphocyte proliferation (> 47,000 cpm) in MLN from both suckling and weaned pigs after TGEV challenge [14].
• Immunization via GALT (gut infection with TGEV) elicited high numbers of IgA ASC and high LPA responses in GALT (gut lamina propria, LP or mesenteric lymph nodes, MLN), but lower responses in BALT (bronchial lymph nodes, BLN) and induced complete protection against enteric TGEV challenge [1].
• Virus-specific lymphocyte proliferation in spleens was delayed in onset and of lower magnitude than that observed in MLN and BLN [14].
• 7. Our results suggest that LMT and porcine motilin stimulate the release of ACh from enteric neurones through the same receptor, and that the release of ACh plays a role in tonic components of contraction in the rabbit duodenum [15].

Associations of MLN with chemical compounds

• Sequence-specific assignments of the proton NMR spectrum of porcine motilin in 30% hexafluoro-2-propanol have been made by using two-dimensional NMR techniques [16].
• The peptide hormone motilin was synthesised with a 13C-enriched alpha-carbon in the leucine at position 10 [17].
• EM-523, an erythromycin derivative, and motilin show similar contractile activity in isolated rabbit intestine [18].
• The results with acetylated derivatives support an ionic interaction between E119 of the MTLR with the N+ of the desosamine sugar in EM-A, but not with the N+ of the free amine group in motilin [11].
• However, bradykinin, porcine motilin and norepinephrine failed to elicit any contraction [19].

Regulatory relationships of MLN

• These findings argue against a major role of circulating PP, gastrin and somatostatin-like components in the control of fasted and post absorptive duodenal motility in pigs while the role of motilin remains equivocal [20].

Other interactions of MLN

• Motilin, a 22-amino acid gastrointestinal peptide, and ghrelin, the natural ligand of the growth hormone secretagogue receptor, form a new group of structurally related peptides [12].
• In the present experimental conditions, duodenal motilin-producing sites were less sensitive to graded luminal acidification than secretin cells [21].
• Circular dichroism spectroscopy has been used to study the behaviour of the cytolytic peptide melittin, the intestinal peptide hormone motilin (porcine) and the neuropeptide galanin (porcine) in various reversed micellar systems [22].
• The effects of atropine (a muscarinic receptor antagonist), spantide (a substance P receptor antagonist) and loxiglumide (a CCK-receptor antagonist) were also examined to determine whether the motilin-induced contraction was independent of those receptors [23].
• To this end, plasma levels of substance P, GRP, motilin, PYY, somatostatin-28, gastrin, and neurotensin were followed for up to 5 days in pigs after a 16-Gy whole-body X-irradiation, completed by a histopathological study performed at 5 days [24].

Analytical, diagnostic and therapeutic context of MLN

• The solution structure of the 22-residue peptide hormone motilin has been studied by circular dichroism and two-dimensional 1H nuclear magnetic resonance spectroscopy [16].
• The contractile response to EM-523 or motilin was reduced markedly after treatment of the preparation with a high concentration of either agent, and cross-tachyphylaxis between EM-523 and motilin was also observed [18].
• Quantitative determination of the polypeptide motilin in rat plasma by externally calibrated liquid chromatography/electrospray ionization mass spectrometry [25].
• Peptides were synthesized using Fmoc solid phase methodology, purified by HPLC, and assayed for their ability to displace bound motilin (rabbit antral smooth muscle homogenate) and to induce contractions (isolated rabbit duodenal segments) [26].
• The presence of motilin in rat and porcine cerebellum was investigated by using high performance liquid chromatography (HPLC) coupled with radioimmunoassay or immunohistochemistry [27].

References