Pressure profiles in neonatal spontaneously hypertensive rats.

Spontaneously hypertensive (SHR) and normotensive (WKY) rats were studied on the day of birth and from 11 days to 12 weeks of age to determine whether increases in arterial pressure are detectable in the early neonatal stage of genetic hypertension. The data show that there are significant increases in systolic, diastolic, and mean pressures in neonatal SHR. Heart rate and heart weight/body weight ratios are also increased and indicate that many parameters, which have been shown to be significantly altered in adult rats in both the early and advanced stages of the disease, are already altered at birth.