||University of Otago Medical School from rats of Wistar origin imported from England in 1930. Selection for high blood pressure started by Smirk in 1955. A number of sublines have been developed. Closely related to strain AS (Heslop and Phelan 1973). Characteristics Develops hypertension, cardiac hypertrophy and vascular disease (Phelan 1968, Simpson and Phelan 1984, Simpson et al, 1994).