COMPARISON OF SALT SENSITIVITY OF MALE AND FEMALE F2 PROGENY FROM CROSSES BETWEEN WKY AND SHRSP RATS

1. The present study compared the salt sensitivity of male and female F-2 progeny obtained from crosses between Wistar-Kyoto/Izumo rats and stroke-prone spontaneously hypertensive rats (SHRSP A(3)b/Izm) after salt loading for 7 months. 2. Average systolic blood pressure in male F-2 progeny was 10 mmHg higher than that of female F-2 progeny at 5 months without salt loading. 3. The blood pressure in male F-2 progeny was raised significantly 2 months after salt loading, but there was no further significant change in blood pressure even though salt loading was continued for 5 months. 4. In female F-2 progeny, however, a significant change in systolic blood pressure was observed 1 month after salt loading and there was a further significant rise in blood pressure over 6 months. 5. Angiotensin I-converting enzyme and RR1023 loci were strongly linked to systolic and diastolic blood pressures in the male but not the female F-2 progeny after salt loading for 7 months. 6. We therefore speculate that the hormonal difference between sexes might influence salt sensitivity in the SHRSP.