Identification of ghrelin in the house musk shrew (Suncus murinus): cDNA cloning, peptide purification and tissue distribution

Ishida, Yuko; Sakahara, Satoshi; Tsutsui, Chihiro; Kaiya, Hiroyuki; Sakata, Ichiro; Oda, Sen-ichi; Sakai, Takafumi

doi:10.1016/j.peptides.2009.01.006

Cited by 40 publications

(35 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Endocannabinoids and ghrelin, which are well-known stimulants of food intake (10,36), also reduce cisplatin-induced emesis in the ferret and least shrew (22,24,33). Similar to effects observed in rodents, ghrelin is present in the gastrointestinal tract of the musk shrew and endocannabinoids have been measured in the brain of the least shrew (11,15). In rodents, fasting increases plasma levels of ghrelin and brain levels of endocannabinoids (12,28), which suggests that similar changes might occur in musk shrews.…”

Section: Discussionmentioning

confidence: 77%

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews

Horn

Still

Fitzgerald

et al. 2010

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

Horn CC, Still L, Fitzgerald C, Friedman MI. Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews. Am J Physiol Gastrointest Liver Physiol 298: G25-G30, 2010. First published November 5, 2009 doi:10.1152/ajpgi.00366.2009.-Nausea and emesis are common side effects of gastrointestinal disease. Reports indicate that ghrelin and endocannabinoids, agents that stimulate appetite, also reduce emesis evoked by chemotherapy treatment, which suggests that stimulation of feeding inhibits the emetic system. In the following study we conducted a more direct test of this hypothesis by determining the impact of manipulating the motivation to eat on emesis, using food restriction and refeeding. Emesis was induced in musk shrews, a commonly used animal model for emesis research, using the cancer chemotherapy agent cisplatin (20 mg/kg ip), nicotine (2 mg/kg sc), or motion (1 Hz, horizontal, 4-cm displacement), because these treatments are known to target separate emetic pathways: gut vagal afferents, area postrema, and vestibular pathways, respectively. Twenty-four hours of food restriction was sufficient to stimulate food intake, and 1 h of refeeding filled the stomach. The results indicate that food restriction, refeeding, and gastric fill had no significant effects on the amount of emesis produced by any of the emetic treatments tested here. This suggests that, although activation of the emetic system might have prominent effects on food intake, neural controls for feeding behavior do not significantly affect the neural pathways for emesis. These results may have implications for how we treat patients who experience a constellation of side effects, including nausea and emesis, since stimulating appetite may not necessarily inhibit emetic pathways.

show abstract

Section: Discussionmentioning

confidence: 77%

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews

Horn

Still

Fitzgerald

et al. 2010

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

show abstract

“…Because there is no cecum in the suncus, it is difficult to distinguish the small intestine and colon. Therefore, in this study, we divided the intestine into six equal segments (intestines 1-6) as previously reported (15,43). All procedures were approved and performed in accordance with the Saitama University Committee on Animal Research.…”

Section: Methodsmentioning

confidence: 99%

“…The suncus is a small mammal that belongs to the order Insectivora, family Soricidae, genus Suncus (3). We previously reported the complete cDNA sequences and tissue distribution of motilin and ghrelin in the suncus (15,43), and reproducible contractile responses of the suncus stomach to suncus or human motilin were found in an in vitro organ bath experiment (43). …”

mentioning

confidence: 96%

Physiological characteristics of gastric contractions and circadian gastric motility in the free-moving conscious house musk shrew (Suncus murinus)

Sakahara

Xie

Koike

et al. 2010

American Journal of Physiology-Regulatory, Integrative and Comp

Self Cite

View full text Add to dashboard Cite

Physiological characteristics of gastric contractions and circadian gastric motility in the free-moving conscious house musk shrew (Suncus murinus). Am J Physiol Regul Integr Comp Physiol 299: R1106 -R1113, 2010. First published August 4, 2010 doi:10.1152/ajpregu.00278.2010.-Although many studies have demonstrated the physiological action of motilin on the migrating motor complex, the precise mechanisms remain obscure. To obtain new insights into the mechanisms, we focused on the house musk shrew (Suncus murinus, suncus used as a laboratory name) as a small model animal for in vivo motilin study, and we studied the physiological characteristics of suncus gastrointestinal motility. Strain gauge transducers were implanted on the serosa of the gastric body and duodenum, and we recorded gastrointestinal contractions in the free-moving conscious suncus and also examined the effects of intravenous infusion of various agents on gastrointestinal motility. During the fasted state, the suncus stomach and duodenum showed clear migrating phase III contractions (intervals of 80 -150 min) as found in humans and dogs. Motilin (bolus injection, 100-300 ng/kg; continuous infusion, 10-100 ng · kg Ϫ1 · min Ϫ1 ) and erythromycin (80 g·kg Ϫ1 · min Ϫ1 ) induced gastric phase III contractions, and motilin injection also increased the gastric motility index in a dose-dependent manner (P Ͻ 0.05, vs. saline). Pretreatment with atropine completely abolished the motilin-induced gastric phase III contractions. On the other hand, in the free-feeding condition, the suncus showed a relatively long fasting period in the light phase followed by spontaneous gastric phase III contractions. The results suggest that the suncus has almost the same gastrointestinal motility and motilin response as those found in humans and dogs, and we propose the suncus as a new small model animal for studying gastrointestinal motility and motilin in vivo.suncus; migrating motor complex; motilin; ghrelin; gastric motility DURING A FASTED STATE, THE stomach and small intestine undergo a temporally coordinated cyclic motor pattern known as migrating motor complex (MMC) in dogs (38) and humans (44). It has been established that these coordinated contractions consist of three phases, phase I (period of motor quiescence), phase II (period of preceding irregular contractions), and phase III (period of clustered potent contractions), and the MMC is stimulated by endogenous motilin that is released in the fasted state.Motilin was originally purified from porcine intestinal mucosa in the 1970s, and its molecular structure was determined to be a 22-amino-acid polypeptide. It has been demonstrated that plasma motilin is released at ϳ100-min intervals at the interdigestive state (20,21). Physiological study of motilin in vivo has been mainly performed by using dogs and humans, and endogenous motilin and exogenous motilin have been shown to induce phase III contractions through the cholinergic pathway because atropine pretreatment completely abolished the motilin-induced contra...

show abstract

“…Suncus murinus belongs to the order Insectivora, family Soricidae, genus Suncus, and this order of animals has been considered one of the most primitive mammals (Douady and Douzery 2003;Ito et al 2002;Murphy et al 2007). Previously, we determined cDNA sequences of S. murinus motilin and ghrelin using PCR cloning (Ishida et al 2009;Tsutsui et al 2009). We then studied the contractile properties of the S. murinus stomach, in both conscious free-moving S. murinus and in an organ bath experiment, and found that S. murinus has almost the same GI motility and motilin response as that found in humans and dogs (Sakahara et al 2010;Tsutsui et al 2009), indicating that S. murinus can be used for GI motility studies.…”

Section: Introductionmentioning

confidence: 99%

The proximal gastric corpus is the most responsive site of motilin-induced contractions in the stomach of the Asian house shrew

et al. 2016

Self Cite

View full text Add to dashboard Cite

The migrating motor complex (MMC) is responsible for emptying the stomach during the interdigestive period, in preparation for the next meal. It is known that gastric phase III of MMC starts from the proximal stomach and propagates the contraction downwards. We hypothesized that a certain region of the stomach must be more responsive to motilin than others, and that motilin-induced strong gastric contractions propagate from that site. Stomachs of the Suncus or Asian house shrew, a small insectivorous mammal, were dissected and the fundus, proximal corpus, distal corpus, and antrum were examined to study the effect of motilin using an organ bath experiment. Motilin-induced contractions differed in different parts of the stomach. Only the proximal corpus induced gastric contraction even at motilin 10(-10) M, and strong contraction was induced by motilin 10(-9) M in all parts of the stomach. The GPR38 mRNA expression was also higher in the proximal corpus than in the other sections, and the lowest expression was observed in the antrum. GPR38 mRNA expression varied with low expression in the mucosal layer and high expression in the muscle layer. Additionally, motilin-induced contractions in each dissected part of the stomach were inhibited by tetrodotoxin and atropine pretreatment. These results suggest that motilin reactivity is not consistent throughout the stomach, and an area of the proximal corpus including the cardia is the most sensitive to motilin.

show abstract

Identification of ghrelin in the house musk shrew (Suncus murinus): cDNA cloning, peptide purification and tissue distribution

Cited by 40 publications

References 33 publications

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews

Food restriction, refeeding, and gastric fill fail to affect emesis in musk shrews

Physiological characteristics of gastric contractions and circadian gastric motility in the free-moving conscious house musk shrew (Suncus murinus)

The proximal gastric corpus is the most responsive site of motilin-induced contractions in the stomach of the Asian house shrew

Contact Info

Product

Resources

About