Proceedings of The Physiological Society

University of Manchester (2010) Proc Physiol Soc 19, PC244

Poster Communications

Intermittent maternal fasting accelerates fetal growth but has no effect on offspring blood pressure in the rat

R. J. Wilkinson1, Y. S. Kaloda2, S. H. Alwasel3, N. Ashton1

1. Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom. 2. Department of Physiology, University of Gezira, Gezira, Sudan. 3. Fetal Programming of Diseases Research Chair, King Saud University, Riyadh, Saudi Arabia.

  • Table 1. Placenta, body and organ weights in E21 control (n=5 litters) and intermittent fasting rats (n=4 litters). Data shown as mean ± SEM. ** P <0.01, *** P <0.001 C vs IF, independent samples t-test.

Maternal malnutrition throughout pregnancy and impaired fetal growth are associated with the development of hypertension in adult human (1) and rat (2) offspring. However, the effects of intermittent fasting (IF) have not been studied in detail. As many Muslim women undergo IF during pregnancy, the aim of this study was to determine the impact of intermittent maternal fasting on fetal growth and blood pressure in a rat model. Control pregnant Wistar rats had access to food ad libitum (C n = 11); in rats subject to intermittent fasting food was withdrawn at 17.00 and returned at 09.00 daily from day 1 of pregnancy until birth; food was available ad libitum for the remainder of the day (e.g. from 09.00 to 17.00) (IF n = 9). All rats had free access to water throughout. Fetal weights were recorded in a sub-group of animals at E21; the remainder proceeded to term after which pup growth was monitored to 10 weeks. Offspring had free access to food throughout. IF rats consumed 27.7 ± 1.7% less food per 100g body weight (P < 0.001) and gained less weight (10.5 ± 5.4% in week 1 rising to 72.1 ± 1.7% in week 3 of control weight gain, P < 0.05) than control dams. Litter sizes did not differ between IF (15.4 ± 0.9) and control rats (15.4 ± 0.8 pups). At E21 (Table 1) IF fetuses were significantly heavier with smaller placentas than controls. IF fetal kidneys and hearts were disproportionately lighter than those of controls. At 4 weeks of age IF pups were lighter than controls (C male 128.2 ± 9.0 vs IF male 107.6 ± 5.4 g, P < 0.01, female data not shown); but their kidneys and hearts were now proportionate to body weight. Systolic blood pressure (SBP) did not differ between IF (94.0 ± 9.1) and control rats (97.3 ± 4.7 mmHg). At 10 weeks IF body weight (390.6 ± 8.5 g) and SBP (115.2 ± 3.0 mmHg) were not different from controls (408.6 ± 9.7 g and 112.0 ± 5.9 mmHg). These data show that IF affects the fetal growth trajectory, producing large fetuses with proportionately smaller kidneys and hearts. However, unlike global food restriction, intermittent fasting did not affect offspring blood pressure.

Where applicable, experiments conform with Society ethical requirements