UNASSIGNED: mGlu1 and mGlu5 metabotropic @entity3264 receptors are expressed in the vertebrate retina, and are co-localized in some retinal neurons. It is believed that both receptors are coupled to polyphosphoinositide (PI) hydrolysis in the retina and their function may diverge in some cells because of a differential engagement of downstream signaling molecules. Here, we show that it is only the mGlu1 receptor that is coupled to PI hydrolysis in the retina. We used either @entity291 retinal slices or intact @entity19 retinas challenged with the mixed mGlu1/5 receptor agonist, @entity11724 . In both models, @entity11724 -stimulated PI hydrolysis was abrogated by the selective mGlu1 receptor antagonist, @entity52641 , but was insensitive to the mGlu5 receptor antagonist, @entity30950 . In addition, the PI response to @entity11724 was unchanged in the retina of mGlu5(-/-) @entity19 but was abolished in the retina of crv4 @entity19 lacking mGlu1 receptors. Stimulation of the mitogen-activated protein kinase pathway by @entity11724 in intact @entity19 retinas were also entirely mediated by mGlu1 receptors. Our data provide the first example of a tissue in which a biochemically detectable PI response is mediated by mGlu1, but not mGlu5, receptors. Hence, @entity291 retinal slices might be used as a model for the functional screening of mGlu1 receptor ligands. In addition, the mGlu1 receptor caters the potential as a drug target in the experimental treatment of @entity179 .

Type-1, but Not Type-5, Metabotropic XXXX Receptors are Coupled to Polyphosphoinositide Hydrolysis in the Retina.

@entity30950 :: ('C121465', 'Chemical') :: ['MPEP'] @entity3264 :: ('D018698', 'Chemical') :: ['glutamate'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity11724 :: ('MESH:C010117', 'Chemical') :: ['DHPG'] @entity179 :: ('MESH:D019636', 'Disease') :: ['degenerative disorders of the retina'] @entity52641 :: ('MESH:C495417', 'Chemical') :: ['JNJ16259685'] @entity291 :: ('9913', 'Species') :: ['bovine']
@entity3264 :: (D018698,Chemical) :: ['Glutamate']
