Interstrain aggression in hypertensive and/or hyperactive rats: SHR, WKY, WKHA, WKHT.

Four inbred rat strains, all derived from Wistar-Kyoto (WKY) rats, express hypertension and hyperactivity in all combinations: SHRs have both traits, WKYs have neither, WKHAs are hyperactive/normotensive, and WKHTs are hypertensive/normoactive. Rats of the four strains were tested for aggression, at one time only, by pairing subjects of same sex, same age, but different strain, in a novel arena, i.e.

Two new inbred rat strains derived from SHR: WKHA, hyperactive, and WKHT, hypertensive, rats.

Two new strains of inbred rats have been developed. One, WKHA, exhibits hyperactivity, and the other, WKHT, exhibits hypertension. Both of these traits are expressed in the SHR.