@phdthesis{oai:sucra.repo.nii.ac.jp:00010420,
 author = {AUVIJIT, SAHA APU},
 month = {},
 note = {viii, 93p, Motilin is a peptide hormone that plays an important role in the regulation of gastrointestinal (GI) motility. In the current study, we determined the cDNA and amino acid sequences of motilin and its receptor (GPR38) in Japanese quail, and studied the distribution of motilin-producing cells and the expression of GPR38 mRNA in the quail GI tract. Using an in vitro organ bath, we examined the motilin-induced contractile properties of different regions of the quail GI tract. We also determined the age-dependent changes and mechanisms of motilin-induced contraction in the proventriculus and duodenum of the quail. Mature quail motilin was composed of 22 amino acids, and showed high homology to chicken (95.4%), human (72.7%), and dog (72.7%) motilin. Immunohistochemical analysis revealed that motilin-immunopositive cells were present in the mucosal layer of the duodenum (23.4 ± 4.6 cells/mm2), jejunum (15.2 ± 0.8 cells/mm2), and ileum (2.5 ± 0.7 cells/mm2), but were not observed in the crop, proventriculus, and colon. We also cloned quail GPR38-encoding cDNA from the medulla oblongata and obtained a partial sequence of 183 bp. Real-time PCR analysis showed that quail GPR38 mRNA was expressed in the crop, proventriculus, duodenum, jejunum, ileum, colon, liver, heart, and muscle. In the organ bath study, chicken motilin evoked dose-dependent contraction of the proventriculus, duodenum, jejunum, and ileum. In contrast, chicken ghrelin had no effect on contraction in the quail GI tract. Motilin-induced contraction in the duodenum was not inhibited by atropine, hexamethonium, ritanserin, ondansetron, GR125487, or tetrodotoxin. However, motilin-induced contractions in the proventriculus were significantly inhibited by atropine and tetrodotoxin. In addition, motilin-induced contraction was significantly decreased with age in the proventriculus, but not in the duodenum. These results suggest that motilin stimulates gastrointestinal motility, and that the site of action for motilin is different between the small intestine and proventriculus of Japanese quail., ABSTRACT　　　　　I
TABLE OF CONTENTS　　　　　III
LIST OF FIGURES　　　　　VI
LIST OF APPENDICES　　　　　VIII
Chapter 1: General introduction and objectives　　　　　1
1.1. Research background　　　　　1
1.1.1. The migrating motor complex of gastrointestinal (GI) motility　　　　　1
1.1.2. Motilin　　　　　2
1.1.3. Ghrelin　　　　　3
1.1.4. Co-ordinated action of motilin and ghrelin in the GI tract　　　　　5
1.1.5. Regulatory mechanism of motilin-induced GI contraction　　　　　5
1.1.6. Japanese quail (Coturnix japonica)　　　　　6
1.2. Purpose of the study　　　　　8
Chapter 2: Molecular cloning of motilin and mechanism of motilin-induced gastrointestinal motility in Japanese quail　　　　　9
2.1. Introduction　　　　　9
2.2. Materials and Methods　　　　　12
2.2.1. Drugs used　　　　　12
2.2.2. Animals　　　　　12
2.2.3. Cloning of quail motilin cDNA　　　　　12
2.2.4. Tissue preparation　　　　　13
2.2.4.1. Immunohistochemistry　　　　　14
2.2.4.2. Morphometric analysis　　　　　15
2.2.5. Organ bath study　　　　　15
2.2.6. Statistical analysis　　　　　17
2.3. Results　　　　　18
2.3.1. Cloning of quail motilin cDNA　　　　　18
2.3.2. Localization of motilin immunopositive (motilin-ip) cells in the GI tract of quail　　　　　18
2.3.3. Effects of motilin on the GI tract of quail　　　　　19
2.3.4. Effects of ghrelin on the GI tract of quail　　　　　19
2.3.5. Effects of co-administration of motilin and ghrelin on the GI tract of quail　　　　　20
2.3.6. Mechanism of chicken motilin-induced contraction in the duodenum of quail　　　　　20
2.3.7. Mechanism of chicken motilin-induced contraction in the proventriculus of quail　　　　　20
2.4. Discussion　　　　　22
2.4.1. cDNA and amino acid sequences of quail motilin　　　　　22
2.4.2. Immunohistochemical analysis of quail motilin　　　　　22
2.4.3. Effects of motilin and ghrelin, alone or together, on gastrointestinal motility in Japanese quail　　　　　23
2.4.4. Mechanism of motilin-induced contraction in quail proventriculus and duodenum　　　　　23
2.4.5. Physiological significance of MMC in relation to motilin　　　　　25
2.5. Summary　　　　　26
Chapter 3: Molecular identification and expression of GPR38 in the gastrointestinal tract of Japanese quail　　　　　27
3.1. Introduction　　　　　27
3.2. Materials and methods　　　　　30
3.2.1. Animals　　　　　30
3.2.2. Cloning of quail GPR38　　　　　30
3.2.3. Reverse transcription (RT) and quantitative real-time PCR (Q-PCR) analysis　　　　　31
3.2.4. Organ bath study　　　　　32
3.2.5. Statistical analysis　　　　　33
3.3. Results　　　　　34
3.3.1. Cloning of quail GPR38　　　　　34
3.3.2. Expression of GPR38 mRNA in quail tissues　　　　　34
3.3.3. Age-dependent changes in motilin-induced contraction in the GI tract of Japanese quail　　　　　34
3.4. Discussion　　　　　36
3.5. Summary　　　　　39
4.0. CONCLUSION　　　　　40
ABBREVIATIONS　　　　　41
REFERENCES　　　　　43
FIGURES　　　　　63
APPENDICES　　　　　87
ACKNOWLEDGEMENTS　　　　　92, 主指導教員 :　坂田一郎, text, application/pdf},
 school = {埼玉大学},
 title = {Regulatory mechanism of motilin-induced gastrointestinal motility in Japanese quail},
 year = {2016},
 yomi = {アビィジッ, サハ アプ}
}