Peripheral corticotropin-releasing factor (CRF) induces stimulation of gastric contractions in freely moving conscious rats: role of CRF receptor types 1 and 2

2012 ◽  
Vol 25 (2) ◽  
pp. 190-197 ◽  
Author(s):  
T. Nozu ◽  
Y. Tsuchiya ◽  
S. Kumei ◽  
K. Takakusaki ◽  
T. Okumura
Keyword(s):  
Corticotropin Releasing Factor ◽  
Conscious Rats ◽  
Freely Moving ◽  
Gastric Contractions ◽  
Stimulation Of

scholarly journals Water-avoidance stress enhances gastric contractions in freely moving conscious rats: role of peripheral CRF receptors

2013 ◽  
Vol 49 (5) ◽  
pp. 799-805 ◽  
Author(s):  
Tsukasa Nozu ◽  
Shima Kumei ◽  
Kaoru Takakusaki ◽  
Toshikatsu Okumura
Keyword(s):  
Conscious Rats ◽  
Freely Moving ◽  
Gastric Contractions

Peripheral urocortin delays gastric emptying: role of CRF receptor 2

1999 ◽  
Vol 276 (4) ◽  
pp. G867-G874 ◽  
Author(s):  
Tsukasa Nozu ◽  
Vicente Martinez ◽  
Jean Rivier ◽  
Yvette Taché
Keyword(s):  
Gastric Emptying ◽  
Abdominal Surgery ◽  
Postoperative Ileus ◽  
Corticotropin Releasing Factor ◽  
Endogenous Ligand ◽  
Gastric Stasis ◽  
Selective Antagonist ◽  
Conscious Rats ◽  
Gastric Ileus

Urocortin, a new mammalian member of the corticotropin-releasing factor (CRF) family has been proposed to be the endogenous ligand for CRF receptor 2 (CRF-R2). We studied the influence of intravenous urocortin on gastric emptying and the role of CRF-R2 in peptide action and postoperative gastric ileus in conscious rats. The intravenous doses of rat CRF and rat urocortin producing 50% inhibition of gastric emptying were 2.5 and 1.1 μg/kg, respectively. At these intravenous doses, CRF and urocortin have their actions fully reversed by the CRF-R1/CRF-R2 antagonist astressin at antagonist/agonist ratios of 5:1 and 67:1, respectively. Astressin (12 μg/kg iv) completely prevented abdominal surgery-induced 54% inhibition of gastric emptying 3 h after surgery while having no effect on basal gastric emptying. The selective nonpeptide CRF-R1 antagonists antalarmin (20 mg/kg ip) and NBI-27914 (400 μg/kg iv) did not influence intravenous CRF-, urocortin- or surgery-induced gastric stasis. These results as well as earlier ones showing that α-helical CRF9—41(a CRF-R2 more selective antagonist) partly prevented postoperative ileus indicate that peripheral CRF-R2 may be primarily involved in intravenous urocortin-, CRF-, and abdominal surgery-induced gastric stasis.

Restraint stress augments postprandial gastric contractions but impairs antropyloric coordination in conscious rats

2006 ◽  
Vol 290 (3) ◽  
pp. R616-R624 ◽  
Author(s):  
Yukiomi Nakade ◽  
Daisuke Tsuchida ◽  
Hiroyuki Fukuda ◽  
Masahiro Iwa ◽  
Theodore N. Pappas ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Gastric Motility ◽  
Restraint Stress ◽  
Delayed Gastric Emptying ◽  
Corticotropin Releasing Factor ◽  
Conscious Rats ◽  
Cholinergic Pathway ◽  
Intracisternal Injection ◽  
Gastric Contractions

Central corticotropin-releasing factor (CRF) plays an important role in mediating restraint stress-induced delayed gastric emptying. However, it is unclear how restraint stress modulates gastric motility to delay gastric emptying. Inasmuch as solid gastric emptying is regulated via antropyloric coordination, we hypothesized that restraint stress impairs antropyloric coordination, resulting in delayed solid gastric emptying in conscious rats. Two strain gauge transducers were sutured onto the serosal surface of the antrum and pylorus, and postprandial gastric motility was monitored before, during, and after restraint stress. Antropyloric coordination, defined as a propagated single contraction from the antrum to the pylorus within 10 s, was followed by ≥20 s of quiescence. Restraint stress enhanced postprandial gastric motility in the antrum and pylorus to 140 ± 9% and 134 ± 9% of basal, respectively ( n = 6). The number of episodes of antropyloric coordination before restraint stress, 2.4 ± 0.4/10 min, was significantly reduced to 0.6 ± 0.3/10 min by restraint stress. Intracisternal injection of the CRF type 2 receptor antagonist astressin 2B (60 μg) or guanethidine partially restored restraint stress-induced impairment of antropyloric coordination (1.6 ± 0.3/10 min, n = 6). The restraint stress-induced augmentation of antral and pyloric contractions was increased by astressin 2B and guanethidine but abolished by atropine, hexamethonium, and vagotomy. Restraint stress enhanced postprandial gastric motility via a vagal cholinergic pathway. Restraint stress-induced delay of solid gastric emptying is due to impairment of antropyloric coordination. Restraint stress-induced impairment of antropyloric coordination might be mediated via a central CRF pathway.

Endogenous ghrelin and 5-HT regulate interdigestive gastrointestinal contractions in conscious rats

2008 ◽  
Vol 295 (2) ◽  
pp. G403-G411 ◽  
Author(s):  
Hiroshi Taniguchi ◽  
Hajime Ariga ◽  
Jun Zheng ◽  
Kirk Ludwig ◽  
Christopher Mantyh ◽  
...  
Keyword(s):  
Duodenal Mucosa ◽  
Phase Iii ◽  
Duodenal Juice ◽  
Ghrelin Receptor ◽  
Conscious Rats ◽  
Freely Moving ◽  
The Relationship ◽  
Distal Jejunum ◽  
Spontaneous Phase

Endogenous ghrelin causes interdigestive contractions of the stomach in rats. In contrast, previous studies showed that 5-HT3 and 5-HT4 receptors were involved in regulating intestinal interdigestive contractions. We studied the possible role of endogenous ghrelin and 5-HT regulating interdigestive gastrointestinal (GI) contractions in rats. Four strain gauge transducers were implanted on the antrum, duodenum, and proximal and distal jejunum. After an overnight fast, GI contractions were recorded in freely moving conscious rats and ghrelin receptor antagonists [(d-lys3)GHRP6; 1 μmol/kg], 5-HT3 antagonists (Ondansetron; 0.5 mg/kg) and 5-HT4 antagonists (GR 125,487; 1 mg/kg) were administered (bolus iv). To evaluate the relationship between the luminal concentrations of 5-HT and phase III-like contractions of the duodenum, duodenal juice was collected via the intraduodenal catheter. 5-HT content of the duodenal juice was measured by HPLC. (d-lys3)GHRP6 significantly attenuated the occurrence and amplitude of phase III-like contractions of the antrum, but not the duodenum and jejunum. 5-HT4 antagonists significantly reduced spontaneous phase III-like contractions of the jejunum, without affecting those of the antrum and duodenum. In contrast, 5-HT3 antagonists did not affect phase III-like contractions in GI tract. Luminal concentration of 5-HT at the phase III-like contraction (36.0 ± 13.3 ng/ml, n = 9) was significantly higher than that at the phase I-like contractions of the duodenum (4.9 ± 1.6 ng/ml, n = 9, P < 0.05). It is suggested that released ghrelin from the gastric mucosa mediates gastric phase III-like contractions, whereas 5-HT released from enterochromaffin cells of the duodenal mucosa mediates intestinal phase III-like contractions via 5-HT4 receptors.

scholarly journals Role of Chemoreceptor Activation in Hemodynamic Responses to Electrical Stimulation of the Carotid Sinus in Conscious Rats

Hypertension ◽  
2015 ◽  
Vol 66 (3) ◽  
pp. 598-603 ◽  
Author(s):  
Pedro L. Katayama ◽  
Jaci A. Castania ◽  
Daniel P.M. Dias ◽  
Kaushik P. Patel ◽  
Rubens Fazan ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Carotid Sinus ◽  
Hemodynamic Responses ◽  
Conscious Rats ◽  
Stimulation Of
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