Short- and long-term effects of a maternal low-protein diet on ventilation, O₂/CO₂chemoreception and arterial blood pressure in male rat offspring

Abstract

Maternal undernutrition increases the risk of adult arterial hypertension. The present study investigated the short-and long-term effects of a maternal low-protein diet on respiratory rhythm, O 2 /CO 2 chemosensitivity and arterial blood pressure (ABP) of the offspring. Male Wistar rats were divided into two groups according to their mothers' diets during gestation and lactation: control (NP, 17 % of casein) and lowprotein (LP, 8 % of casein) groups. Direct measurements of ABP, respiratory frequency (RF), tidal volume (V T ) and ventilation (VE), as well as hypercapnia (7 % CO 2 ) and hypoxia (7 % O 2 ) evoked respiratory responses were recorded from the awake male offspring at the 30th and 90th days of life. Blood samples were collected for the analyses of protein, creatinine and urea concentrations. The LP offspring had impaired body weight and length throughout the experiment. At 30 d of age, the LP rats showed a reduction in the concentrations of total serum protein (approximately 24 %). ABP in the LP rats was similar to that in the NP rats at 30 d of age, but it was 20 % higher at 90 d of age. With respect to ventilatory parameters, the LP rats showed enhanced RF (approximately 34 %) and VE (approximately 34 %) at 30 d of age, which was associated with increased ventilatory responses to hypercapnia (approximately 21 % in VE) and hypoxia (approximately 82 % in VE). At 90 d of age, the VE values and CO 2 /O 2 chemosensitivity of the LP rats were restored to the control range, but the RF values remained elevated. The present data show that a perinatal LP diet alters respiratory rhythm and O 2 /CO 2 chemosensitivity at early ages, which may be a predisposing factor for increased ABP at adulthood.

Birthweight, body composition, and motor performance in 7‐ to 10‐year‐old children

“…5 Postnatal catch-up growth and high fat accumulation during infancy/childhood have been associated with significantly increased risk of cardiovascular disorders in adulthood and reduced lifespan. 4,[25][26][27][28] In terms of motor performance, birthweight was positively associated with handgrip strength and negatively The average of left and right hand scores is shown. BMI, body mass index; FFM, fat-free mass; VO 2max , maximal oxygen consumption.…”

“…4,[25][26][27][28] In terms of motor performance, birthweight was positively associated with handgrip strength and negatively associated with 20-meter sprint time. To adjust for confounding factors, we used different multiple linear regression models, and it was shown that birthweight predicted handgrip and 20-meter sprint time across all models (age, age 2 , height, BMI, FFM, and % body fat).…”

Maternal Protein Restriction Increases Respiratory and Sympathetic Activities and Sensitizes Peripheral Chemoreflex in Male Rat Offspring

“…Offspring were standardized as litters of 8 pups 48 h after birth. Male offspring were used in each litter and females were used only to standardize the size of each litter to 8 pups (7). At weaning, 3 or 4 male offspring from each litter were randomly housed in collective cages and received a standard diet ad libitum.…”

“…We recently showed that juvenile rats subjected to protein undernutrition during gestation and lactation exhibit increased baseline respiratory frequency associated with amplified ventilatory responses to hypoxia and hypercapnia (7). These findings indicated that the functioning of the respiratory network, in addition to that of the sympathetic nervous system, is affected by an LP diet during gestation and lactation, likely through a common excitation mechanism.…”

“…The offspring of rat dams subjected to a maternal low-protein (LP) 10 diet is a model that is often used to study the mechanisms of maternal undernutrition-related hypertension (6)(7)(8), which has been suggested to be associated with changes in the functioning of the sympathetic nervous system (9,10). However, there is no direct evidence demonstrating that sympathetic vasoconstrictor tonus is elevated in rats subjected to a perinatal LP diet.…”