Effects of a high maternal sodium intake on offspring of genetically diverse (CCHS) mice

Abstract

The present study sought to determine whether a high maternal salt intake during pregnancy and lactation affected offspring blood pressure (BP), heart rate (HR), or locomotor activity in a genetically diverse stock of mice (Collaborative Cross Heterozygous Stock, CCHS). Dams were fed a low or high salt diet (0.25% NaCl (LS) vs 5% NaCl (HS)) from before conception through weaning, and telemetry studies were performed in 10 month old male offspring raised on either the LS or HS diet. A maternal HS diet was associated with significantly smaller litter sizes (P=0.03, data from groups of 34 and 37 litters), but offspring weight was not affected at any time between the day of birth (data from 22 and 24 litters) and 10 months of age (group sizes ≥ 11). Telemetry studies revealed no effects of maternal HS on mean BP or HR. However, maternal HS was associated with increased circadian variation in BP, increased percentage of time spent active during the 12h light period, and a tendency towards increased pulse pressure (P=0.03, 0.04, 0.06, respectively, group sizes of 8 – 14). Our results indicate that a maternal high salt diet does not affect offspring mean BP level in 10 month old male CCHS mice, but does reduce litter size and has subtle effects on activity and blood pressure cycles. Supported by the Canadian Institutes of Health Research (#91547).