In the present study, we have demonstrated that PBR sites are present in the microsomal fraction from rat liver, heart and kidney, which we have named the non-mitochondrial PBR. The non-mitochondrial PBR was pharmacologically characterized by porphyrin competition experiments. The ability of porphyrins to differentially compete for specific (3H) Ro5-4864 or (3H) PK11195 binding demonstrated that the mitochondrial and non-mitochondrial PBR have different affinities for selected porphyrin compounds. These results suggest that the mitochondrial and non-mitochondrial PBR have a different binding pharmacology and support the existence of a non-mitochondrial PBR site. On the other hand, porphyrins show different potencies in competing for specific (3H) Ro5-4864 and (3H) PK11195 binding in the same fraction. In addition, the results of saturation experiments show that there are more PK11195 binding sites than Ro5-4864 binding sites in all fractions examined. This observation suggests that the sites labeled by (3H) Ro5-4864 and (3H) PK11195 are not identical.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277848 |
| Date | January 1991 |
| Creators | Li, Hong Bing, 1966- |
| Contributors | Laird, Hugh E., II |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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