Blood pressure and heart rate changes during pregnancy in fructose-fed Sprague-Dawley rats

Abstract

Blood pressure and heart rate changes during pregnancy were investigated in fructose-fed (diabetic) Sprague-Dawley rats. A total of48 pubertal female rats were used. The experimental rats were fed with 25% (w/w) fructose mixed with normal rat chow for minimum period of 3 weeks while the control rats were fed with the normal rat chow. They all had free access to drinking water. Systolic, diastolic and mean arterial blood pressures and the heart rates were measured in both non-pregnant and pregnant control rats and their diabetic counterparts . The results indicate that systolic blood pressures significantly increased progressively during pregnancy in fructose-fed rats as compared with the non-pregnant rats (/><0.0001) while in the control rats, except for the 2 nd trimester sub-group, which had a similar value with the nonpregnant sub-group, the systolic blood pressure (SBP) also, increased steadily. When the diabetic group is compared with the control group, the SBP (in the 2 nd trimester subgroups) was raised from 82.18±1.26mmHg in control rats to 112.48± 1.26mmHg in the diabetic rats (PO.OOO1). Diastolic blood pressure (DBP) progressively increased significantly in the diabetic rats from 63.94±3.95mmHg in the non-pregnant sub-group to 91.95±1.89mmHg in the 3 rd trimester subgroup of the pregnant rats (/^O.OOOl). The DBP of the 2 nd trimester subgroup of the diabetic rats was significantly raised from 61.88± 4.20mmH g in the control rats to 89.60±1.79mmHg in the diabetic rats (/^O.OOOl). In addition, the mean arterial blood pressure (MAP) was significantly raised in the 1" and 2 nd trimester of the diabetic rats from 70.61 ±3.12mmHg in the non-pregnant diabetic rats to 96.28±1,36mmHg and 97.13 ±1.15mmHg respectively, (^<0.0001, P<0.0001). There was a progressive increase in the heart rates, in both control and diabetic groups, from non pregnant sub-groups to the 3 trimesters of pregnancy. The body weights of the 2 groups of rats increased significantly as pregnancy progressed. These results suggest that fructose induced diabetes could cause the development of sustained hypertension during pregnancy via the insulin-resistance hyperinsulinemia-link.