Xenopsin immunoreactivity in antral G-cells may reside in the N-terminus of gastrin 17
✍ Scribed by C. F. Johnston; C. Shaw; J. E. S. Ardill; J. M. Sloan; K. D. Buchanan
- Publisher
- Springer
- Year
- 1988
- Tongue
- English
- Weight
- 805 KB
- Volume
- 90
- Category
- Article
- ISSN
- 1432-119X
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✦ Synopsis
The nature of xenopsin immunoreactivity in mammalian antral G-cells has been reassessed. Xenopsin immunostaining was most intense in human antral G-cells, present in those of the dog and pig and not detected in guinea pig or rat tissues. Rigorous specificity controls for ionic binding of immunoglobulins to antral G-cell granules indicated that this mechanism was not responsible for xenopsin immunostaining. Preincubation of the xenopsin antiserum with xenopsin, human gastrin 1-13 and gastrin 2-17 completely abolished immunostaining at similar molar concentrations. Gastrin 34 was ineffective at much higher concentrations. These results infer that xenopsin-immunoreactivity in antral G-cells resides in the N-terminal region of gastrin 17. Examination of the primary structures of xenopsin and the N-terminal regions of some mammalian gastrins reveals a hitherto unrecognized homology.