The Sabra hypertension prone (H) and hypertension resistant (N) rat strain.

By selective inbreeding of the Hebrew University Sabra rat, we have obtained a hypertension prone (H) and a hypertension resistant (N) substrain. The criteria for selection was the blood pressure response to DOCA-salt. The outstanding element of our model is the N rat with its remarkable resistance to hypertension. When compared to H, the N rat presents the following characteristics: 1. The blood pressure of experimentally naive N rats is significantly lower at comparable ages, in both sexes. 2. N rats are resistant to both DOCA-salt and renal clip hypertension. 3. In the medulla oblongata (MO) of N rats, the noradrenaline (NA) content is significantly higher and the activity of tyrosine hydroxylase is significantly lower. 4. In the MO of N rats, the sensitivity of the NA dependent cAMP generating system is significantly decreased. 5. In the atrium of N rats, the NA content is significantly higher, and is unaffected by DOCA-salt treatment. The results suggest that genetic differences in catecholamine metabolism may account for the disparate susceptibility to hypertension of the two strains.