Abstract:

In the present study, We investigated beta receptor binding with radioligand binding technic in various brain regions in 6-weeks and 20-weeks old hypertensive and normotensive rats. Our results were followings; 1) In normotensive rats, beta-rector binding was more decreased in the 20 weeks than in 6 weeks, while in SHR, beta-receptor binding was more increased in the 20 weeks than in 6 weeks, especially in the region of cortex, striatum and hippocampus.2) We investigated how light-dark cycle influenced on receptor binding. The results were that in the 6-weeks SHR light-dark cycle influenced on receptor binding in the region of cortex, medulla and hippocampus, but in the 20-week hypertensive rats, did not. 3) Comparing the difference in beta-receptir binding between SHR and normotensive rats, in the 6-weeks SHR before hypertension developed, beta-receptor binding was more decreased than in normotensive rats, in the region of cortex, midbrain and medulla. In the 20-week SHR compared with normotensive rats, beta-receptor binding was more increased in cotex, cerebellum and hippocampus but more decreased in midbrain medulla. These result suggest that in SHR, the abnormal reponse to light dark cycle and the change of beta-receptor binding and decrease of β-receptir in medulla plays an important role in the development and maintenance of hypertension.And also it is suggestd that the differences of beta-receptor binding between SHR and normotensive rats are influenced by the variables of age and brain regions (J Kor Soc Endocrinol 5: 108~119, 1990).