Bombesin and neurotensin are neuropeptides which exert a wide spectrum of biological actions on gastrointestinal tissues influencing intestinal growth and adaptation, intestinal motility, blood flow, secretion, nutrie...Bombesin and neurotensin are neuropeptides which exert a wide spectrum of biological actions on gastrointestinal tissues influencing intestinal growth and adaptation, intestinal motility, blood flow, secretion, nutrient absorption and immune response. Based mainly on their well-established potent enterotrophic effect, numerous experimental studies investigated their potential positive effect on the atrophic or injured intestinal mucosa. These peptides proved to be effective mucosa-healing factors, but the potential molecular and cellular mechanisms for this action remained unresolved. In a recently published study (World J Gastroenterol 2008; 14(8): 1222-1230), it was shown that their protective effect on the intestine in experimentally induced inflammatory bowel disease was related to anti-inflammatory, antioxidant and antiapoptotic actions. These results are in close agreement with our previous studies on jaundiced and hepatectomized rats that showed a regulatory effect of bombesin and neurotensin on critical cellular processes such as enterocyte' proliferation and death, oxidative stress and redox equilibrium, tight junctions' formation and function, and inflammatory response. The pleiotropic effects of bombesin and neurotensin on diverse types of intestinal injury may justify their consideration for clinical trials.展开更多
AIM： To investigate the mechanism of bombesin-induced circular smooth muscle cell contraction in cat esophagus. METHODS： Specific G protein or phospholipase C involved in cat esophagus contraction was identified, mu...AIM： To investigate the mechanism of bombesin-induced circular smooth muscle cell contraction in cat esophagus. METHODS： Specific G protein or phospholipase C involved in cat esophagus contraction was identified, muscle cells were permeabilized with saponin. After per- meabilization of muscle cells, the Gi3 antibody inhibited bombesin-induced smooth muscle cell contraction. RESULTS： Incubation of permeabilized circular muscle cells with PLC-β3 antibody could inhibit bombesin-induced contraction. H-7, chelerythrine （PKC inhibitor） and genistein （protein tyrosine kinase inhibitor） inhibited bombesin-induced contraction, but DAG kinase inhibitor, R59949, could not inhibit it. To examine which mitogen-activated protein kinase （MAPK） was involved in bombesin-induced contTaction, the specific MAPK inhibitors （MEK inhibitor, PD98059 and p38 MAPK inhibitor, SB202190） were used. Preincubation of PD98059 blocked the contraction induced by bombesin in a concentration-dependent manner. However, SB202190 had no effects on contraction. CONCLUSION： Bombesin-induced circular muscle cell contraction in cat esophagus is mediated via a PKC or a PTK-dependent pathway or p44/p42 HAPK pathway.展开更多
文摘Bombesin and neurotensin are neuropeptides which exert a wide spectrum of biological actions on gastrointestinal tissues influencing intestinal growth and adaptation, intestinal motility, blood flow, secretion, nutrient absorption and immune response. Based mainly on their well-established potent enterotrophic effect, numerous experimental studies investigated their potential positive effect on the atrophic or injured intestinal mucosa. These peptides proved to be effective mucosa-healing factors, but the potential molecular and cellular mechanisms for this action remained unresolved. In a recently published study (World J Gastroenterol 2008; 14(8): 1222-1230), it was shown that their protective effect on the intestine in experimentally induced inflammatory bowel disease was related to anti-inflammatory, antioxidant and antiapoptotic actions. These results are in close agreement with our previous studies on jaundiced and hepatectomized rats that showed a regulatory effect of bombesin and neurotensin on critical cellular processes such as enterocyte' proliferation and death, oxidative stress and redox equilibrium, tight junctions' formation and function, and inflammatory response. The pleiotropic effects of bombesin and neurotensin on diverse types of intestinal injury may justify their consideration for clinical trials.
文摘AIM： To investigate the mechanism of bombesin-induced circular smooth muscle cell contraction in cat esophagus. METHODS： Specific G protein or phospholipase C involved in cat esophagus contraction was identified, muscle cells were permeabilized with saponin. After per- meabilization of muscle cells, the Gi3 antibody inhibited bombesin-induced smooth muscle cell contraction. RESULTS： Incubation of permeabilized circular muscle cells with PLC-β3 antibody could inhibit bombesin-induced contraction. H-7, chelerythrine （PKC inhibitor） and genistein （protein tyrosine kinase inhibitor） inhibited bombesin-induced contraction, but DAG kinase inhibitor, R59949, could not inhibit it. To examine which mitogen-activated protein kinase （MAPK） was involved in bombesin-induced contTaction, the specific MAPK inhibitors （MEK inhibitor, PD98059 and p38 MAPK inhibitor, SB202190） were used. Preincubation of PD98059 blocked the contraction induced by bombesin in a concentration-dependent manner. However, SB202190 had no effects on contraction. CONCLUSION： Bombesin-induced circular muscle cell contraction in cat esophagus is mediated via a PKC or a PTK-dependent pathway or p44/p42 HAPK pathway.
