Receptor adaptive responsiveness in disease models: 6-OHDA lesioned and spontaneously hypertensive rats

We have examined the adaptive modifications of brain monoamine receptors in response to pathophysiological processes in animal disease models: 6-OHDA lesioned and spontaneously hypertensive rats (SHR). The two models share a similar increase in D-1 receptor densities, while noradrenergic receptors are affected in different way: alpha-1 and beta are supersensitive in 6-OHDA lesioned rats and only alpha-2 are increased in SHR. S-1 receptors too are up-regulated in SHR. We must notice that though receptor hypersensitivity in the 6-OHDA model is linked to massive decreases in neurotransmitter levels, this mechanism seems not to exist in the SHR model.