Phenotypes associated with this allele

• Allele Symbol: Hrh2^tm1Wtn
• Allele Name: targeted mutation 1, Takeshi Watanabe
• Allele ID: MGI:2182949
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Hrh2^tm1Wtn/Hrh2^tm1Wtn	involves: 129P2/OlaHsd * C57BL/6J	MGI:2182966

Genotype
MGI:2182966

hm1

• Allelic Composition: Hrh2^tm1Wtn/Hrh2^tm1Wtn
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

digestive/alimentary system

abnormal stomach mucosa morphology ( J:62871 )

• enterochromaffin-like (ECL) cells are increased in number and are found not only in the basal region, but also in the neck region and isthmus

• increase in H⁺, K⁺-ATPase negative cells in the isthmus and neck region

• histamine content in the gastric mucosa is elevated

• young mice (4 weeks old) in which hypertrophy of the oxyntic mucosa is not yet seen, exhibit a significant increase in cell proliferation in the mucosa

abnormal gastric parietal cell morphology ( J:62871 )

• parietal cells are increased in number, are smaller and contain enlarged secretory canaliculi with a lower density of microvilli and few typical tubulovesicles in the narrow cytoplasm

increased stomach mucosa thickness ( J:62871 )

• thickness of the oxyntic mucosa in the glandular region is increased in 16-week old mutants resulting in the formation of enlarged gastric folds

• change in mucosal thickness is most prominent in the isthmus and neck region

decreased digestive secretion ( J:62871 )

• induction of gastric acid secretion by histamine or gastrin is completely abolished, however carbachol still induced secretion

abnormal stomach pH ( J:62871 )

• basal gastric pH is normal, however elevation of gastric pH by administration of an Hrh2 antagonist, famotidine, is not observed

homeostasis/metabolism

increased circulating gastrin level ( J:62871 )

• 12- to 18-week old mutants exhibit elevated serum gastrin levels (hypergastrinemia)

endocrine/exocrine glands

abnormal gastric parietal cell morphology ( J:62871 )

• parietal cells are increased in number, are smaller and contain enlarged secretory canaliculi with a lower density of microvilli and few typical tubulovesicles in the narrow cytoplasm