{"id":{"repo_id":"waikato-masters","oai_identifier":"oai:researchcommons.waikato.ac.nz:10289/17555"},"canonical_url":"https://search.dev.ndltd.org/etd/waikato-masters/oai:researchcommons.waikato.ac.nz:10289/17555","repository":{"repo_id":"waikato-masters","name":"University Waikato","base_url":"https://researchcommons.waikato.ac.nz/server/oai/request"},"display":{"title":"An investigation of the distribution of gastrin-like activity, and its nature, in the gastrointestinal tract of the sheep","abstract":"Using a modification of the extraction procedure of Gregory and Tracy (1964), and a perfused rat stomach bioassay, gastrin-like activity has been located in the ovine rumen, reticulum, omasum, abomasal body, antrum, duodenum and caecum. The antrum showed the highest concentration of gastrin-like activity, but substantial concentrations were found in the rumen, reticulum, omasum and caecum and proximal duodenum declining progressively with distance from the pylorus. A lesser concentration occurred in the abomasal body. Consideration of the relative total content of gastrin-like activity showed that the amount of extra-antral activity was substantial. The active principle was unlikely to have been cholecystokinin as the extracts had isoelectric points of a more acidic nature than that of cholecystokinin. Similarly, bioassay using an isolated guinea-pig ileum showed histamine to be absent from the extracts. Extraction of rumenal, reticular, omasal, abomasal body and antral mucosa and muscle separately showed that the gastrin-like activity resided almost completely in the mucosa. An investigation of the gastrin-like activity of air dried and freeze dried extracts showed that the freeze dried extracts were approximately 50% more active than the air dried extracts. Bioassay of a freeze dried antral extract over a twenty four week period showed that the activity was maintained for the initial six weeks, and that 80% of the activity was then lost over the following eighteen weeks. Studies using columns of Sephadex have shown that extracts from all regions of the ovine gastro-intestinal tract investigated were similar and consisted of several components of differing molecular weight. By a comparison of their respective molecular weights, to those reported for components separated from extracts of non-ruminant origin, it seems likely that components corresponding to MG, HLG, BG, BBG and component I were present in varying amounts. The response to infusions of gastrin extract in fed and fasted sheep were different. In fasted sheep infusions of extract, after a relatively long latent period, caused a small, but prolonged increase in acid secretion. In contrast pentagastrin caused an immediate and pronounced response. In fed sheep the responses were variable. Experiments on a single dolphin (Delphinus delpis) have shown there to be gastrin-like activity present in the forestomach, mainstomach, pyloric stomach, duodenal ampulla and intestine of this mammal. The distribution of gastrin-like activity reported in the present work has been compared to previous reports concerning the distribution of gastrin activity in animals with a more simple stomach, and the possible function of gastrin in the ruminant has been discussed.","abstract_html":"Using a modification of the extraction procedure of Gregory and Tracy (1964), and a perfused rat stomach bioassay, gastrin-like activity has been located in the ovine rumen, reticulum, omasum, abomasal body, antrum, duodenum and caecum. The antrum showed the highest concentration of gastrin-like activity, but substantial concentrations were found in the rumen, reticulum, omasum and caecum and proximal duodenum declining progressively with distance from the pylorus. A lesser concentration occurred in the abomasal body. Consideration of the relative total content of gastrin-like activity showed that the amount of extra-antral activity was substantial. The active principle was unlikely to have been cholecystokinin as the extracts had isoelectric points of a more acidic nature than that of cholecystokinin. Similarly, bioassay using an isolated guinea-pig ileum showed histamine to be absent from the extracts. Extraction of rumenal, reticular, omasal, abomasal body and antral mucosa and muscle separately showed that the gastrin-like activity resided almost completely in the mucosa. An investigation of the gastrin-like activity of air dried and freeze dried extracts showed that the freeze dried extracts were approximately 50% more active than the air dried extracts. Bioassay of a freeze dried antral extract over a twenty four week period showed that the activity was maintained for the initial six weeks, and that 80% of the activity was then lost over the following eighteen weeks. Studies using columns of Sephadex have shown that extracts from all regions of the ovine gastro-intestinal tract investigated were similar and consisted of several components of differing molecular weight. By a comparison of their respective molecular weights, to those reported for components separated from extracts of non-ruminant origin, it seems likely that components corresponding to MG, HLG, BG, BBG and component I were present in varying amounts. The response to infusions of gastrin extract in fed and fasted sheep were different. In fasted sheep infusions of extract, after a relatively long latent period, caused a small, but prolonged increase in acid secretion. In contrast pentagastrin caused an immediate and pronounced response. In fed sheep the responses were variable. Experiments on a single dolphin (Delphinus delpis) have shown there to be gastrin-like activity present in the forestomach, mainstomach, pyloric stomach, duodenal ampulla and intestine of this mammal. The distribution of gastrin-like activity reported in the present work has been compared to previous reports concerning the distribution of gastrin activity in animals with a more simple stomach, and the possible function of gastrin in the ruminant has been discussed.","abstract_has_math":false,"creators":["Jury, Denis R."],"institution":"The University of Waikato","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["McLeay, Lance M."],"committee_chairs":[],"committee_members":[],"year":1978,"date_issued":"1978","date_published":"1978","updated_at":"2026-07-24T05:57:21Z","subjects":[],"languages":[],"rights":["All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated."],"rights_urls":["https://researchcommons.waikato.ac.nz/bitstreams/e1034ae0-cda1-4486-9d48-36c5982281e9/download"],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["McLeay, Lance M."]},{"key":"dc:creator","label":"Author","values":["Jury, Denis R."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["1978"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["The University of Waikato"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://hdl.handle.net/10289/17555"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["https://researchcommons.waikato.ac.nz/bitstreams/e1034ae0-cda1-4486-9d48-36c5982281e9/download","All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://researchcommons.waikato.ac.nz/bitstreams/52fed122-8f3e-4777-8204-9f30781c6419/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Using a modification of the extraction procedure of Gregory and Tracy (1964), and a perfused rat stomach bioassay, gastrin-like activity has been located in the ovine rumen, reticulum, omasum, abomasal body, antrum, duodenum and caecum. The antrum showed the highest concentration of gastrin-like activity, but substantial concentrations were found in the rumen, reticulum, omasum and caecum and proximal duodenum declining progressively with distance from the pylorus. A lesser concentration occurred in the abomasal body. Consideration of the relative total content of gastrin-like activity showed that the amount of extra-antral activity was substantial. The active principle was unlikely to have been cholecystokinin as the extracts had isoelectric points of a more acidic nature than that of cholecystokinin. Similarly, bioassay using an isolated guinea-pig ileum showed histamine to be absent from the extracts. Extraction of rumenal, reticular, omasal, abomasal body and antral mucosa and muscle separately showed that the gastrin-like activity resided almost completely in the mucosa. An investigation of the gastrin-like activity of air dried and freeze dried extracts showed that the freeze dried extracts were approximately 50% more active than the air dried extracts. Bioassay of a freeze dried antral extract over a twenty four week period showed that the activity was maintained for the initial six weeks, and that 80% of the activity was then lost over the following eighteen weeks. Studies using columns of Sephadex have shown that extracts from all regions of the ovine gastro-intestinal tract investigated were similar and consisted of several components of differing molecular weight. By a comparison of their respective molecular weights, to those reported for components separated from extracts of non-ruminant origin, it seems likely that components corresponding to MG, HLG, BG, BBG and component I were present in varying amounts. The response to infusions of gastrin extract in fed and fasted sheep were different. In fasted sheep infusions of extract, after a relatively long latent period, caused a small, but prolonged increase in acid secretion. In contrast pentagastrin caused an immediate and pronounced response. In fed sheep the responses were variable. Experiments on a single dolphin (Delphinus delpis) have shown there to be gastrin-like activity present in the forestomach, mainstomach, pyloric stomach, duodenal ampulla and intestine of this mammal. 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The antrum showed the highest concentration of gastrin-like activity, but substantial concentrations were found in the rumen, reticulum, omasum and caecum and proximal duodenum declining progressively with distance from the pylorus. A lesser concentration occurred in the abomasal body. Consideration of the relative total content of gastrin-like activity showed that the amount of extra-antral activity was substantial. The active principle was unlikely to have been cholecystokinin as the extracts had isoelectric points of a more acidic nature than that of cholecystokinin. Similarly, bioassay using an isolated guinea-pig ileum showed histamine to be absent from the extracts. Extraction of rumenal, reticular, omasal, abomasal body and antral mucosa and muscle separately showed that the gastrin-like activity resided almost completely in the mucosa. An investigation of the gastrin-like activity of air dried and freeze dried extracts showed that the freeze dried extracts were approximately 50% more active than the air dried extracts. Bioassay of a freeze dried antral extract over a twenty four week period showed that the activity was maintained for the initial six weeks, and that 80% of the activity was then lost over the following eighteen weeks. Studies using columns of Sephadex have shown that extracts from all regions of the ovine gastro-intestinal tract investigated were similar and consisted of several components of differing molecular weight. By a comparison of their respective molecular weights, to those reported for components separated from extracts of non-ruminant origin, it seems likely that components corresponding to MG, HLG, BG, BBG and component I were present in varying amounts. The response to infusions of gastrin extract in fed and fasted sheep were different. In fasted sheep infusions of extract, after a relatively long latent period, caused a small, but prolonged increase in acid secretion. In contrast pentagastrin caused an immediate and pronounced response. In fed sheep the responses were variable. Experiments on a single dolphin (Delphinus delpis) have shown there to be gastrin-like activity present in the forestomach, mainstomach, pyloric stomach, duodenal ampulla and intestine of this mammal. 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