Changes in brainstem and spinal adrenoceptor binding with ageing in spontaneously hypertensive and Wistar-Kyoto rats

Adrenoceptor binding in membranes prepared from the brainstem and thoracic spinal cord of male spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats aged 6 and 36-40 weeks has been compared. Binding of [3H]prazosin (alpha 1-receptors), [3H]rauwolscine (alpha 2-receptors) and [3H]dihydroalprenolol (DHA: beta-receptors) fell with age in both regions in both strains. Strain, independent of age, was also a significant determinant of binding for all three ligands in brainstem and for [3H]DHA in spinal cord. The changes in receptor binding may reflect differences in noradrenergic activity with age and between SHR and WKY rats.