ENVIRONMENTAL FACTOR(S) DURING SUCKLING EXERT LONG-TERM EFFECTS UPON BLOOD-PRESSURE AND BODY-WEIGHT IN SPONTANEOUSLY HYPERTENSIVE AND NORMOTENSIVE RATS

To define the role of nurse and pup strain (spontaneously hypertensive rats: SHR nurses and shr pups; Wistar-Kyoto rats: WKY nurses and wky pups) and dietary salt in nurses and pups (low salt and high salt) upon pup body weight and blood pressure, we cross-suckled shr and wky from birth. Nurses after delivery and pups after weaning received either low- or high-salt diets. Pup body weight indicated that WKY dams were better nurses than SHR and that high salt in the nurse and pup diet decreased body weight. At 7 days, WKY on a low-salt diet normalized shr blood pressure and SHR on a high-salt diet reduced shr blood pressure. At 100 days, pup strain strongly affected blood pressure. Salt sensitivity to pup dietary salt depended upon a low-salt diet in nurses. Salt resistance depended on a high-salt diet in WKY nurses. At 300 days, pup strain accounted for most of the blood pressure variability. However, pup diet, pup strain and nurse diet also affected blood pressure (P = 0.05); the blood pressure of shr on a high-salt diet was higher if the nurse was an SHR on a high-salt diet. Thus, nurse environment modulated shr hypertension throughout life.