| First Author | Jagoda EM | Year | 2003 |
| Journal | Neuropharmacology | Volume | 44 |
| Issue | 5 | Pages | 653-61 |
| PubMed ID | 12668051 | Mgi Jnum | J:97005 |
| Mgi Id | MGI:3574139 | Doi | 10.1016/s0028-3908(03)00050-9 |
| Citation | Jagoda EM, et al. (2003) Regional brain uptake of the muscarinic ligand, [18F]FP-TZTP, is greatly decreased in M2 receptor knockout mice but not in M1, M3 and M4 receptor knockout mice. Neuropharmacology 44(5):653-61 |
| abstractText | A muscarinic receptor radioligand, 3-(3-(3-fluoropropyl)thio) -1,2,5,thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine (fP-TZTP) radiolabeled with the positron emitting radionuclide (18)F ([(18)F]FP-TZTP) displayed regional brain distribution consistent with M2 receptor densities in rat brain. The purpose of the present study is to further elucidate the subtype selectivity of [(18)F]FP-TZTP using genetically engineered mice which lacked functional M1, M2, M3, or M4 muscarinic receptors. Using ex vivo autoradiography, the regional brain localization of [(18)F]FP-TZTP in M2 knockout (M2 KO) was significantly decreased (51.3 to 61.4%; P<0.01) when compared to the wild-type (WT) mice in amygdala, brain stem, caudate putamen, cerebellum, cortex, hippocampus, hypothalamus, superior colliculus, and thalamus. In similar studies with M1KO, M3KO and M4KO compared to their WT mice, [(18)F]FP-TZTP uptakes in the same brain regions were not significantly decreased at P<0.01. However, in amygdala and hippocampus small decreases of 19.5% and 22.7%, respectively, were observed for M1KO vs WT mice at P<0.05. Given the fact that large decreases in [(18)F]FP-TZTP brain uptakes were seen only in M2 KO vs. WT mice, we conclude that [(18)F]FP-TZTP preferentially labels M2 receptors in vivo. |
