Low-protein diet impairs vascular relaxation in virgin and pregnant rats

2002 ◽  
Vol 102 (5) ◽  
pp. 553-560 ◽  
Author(s):  
Angeliki KOUMENTAKI ◽  
Frederick ANTHONY ◽  
Lucilla POSTON ◽  
Timothy WHEELER

Pregnancy is associated with increases in maternal cardiac output and plasma volume and a reduction in peripheral vascular resistance. Cardiac output and plasma volume are substantially reduced in pregnant rats fed a low-protein diet, but it is not known whether vascular function is also compromised. We have investigated vascular function in virgin and pregnant Wistar rats subjected to dietary protein restriction [9% (w/v) casein, compared with 18% (w/v) casein for controls]. The diets were fed to the groups for 18 days; in the pregnant rats, the diets were given from day 1 of pregnancy. Branches of the mesenteric arteries were studied on day 18 of the dietary period using myography. Significant reductions in sensitivity to acetylcholine occurred in vessels from virgin (P = 0.04) and pregnant (P = 0.01) rats that had consumed the 9% casein diet. In arteries from the virgin rats on the restricted diet there was also a significant reduction in sensitivity (P = 0.0003) and maximum relaxation (P = 0.009) to the NO donor spermine NONOate. Mean placental and fetal weights were significantly lower in the rats fed on 9% casein (P<0.0001 and P = 0.005 respectively). Thus low-protein diets impair vasodilator responses in female rats. These effects may contribute to the poor cardiovascular adaptation to pregnancy and lower fetal weights associated with restricted protein intake.

2019 ◽  
Vol 34 (6) ◽  
pp. 1531-1546 ◽  
Author(s):  
Ravinder Naik Dharavath ◽  
Shiyana Arora ◽  
Mahendra Bishnoi ◽  
Kanthi Kiran Kondepudi ◽  
Kanwaljit Chopra

2015 ◽  
Vol 308 (5) ◽  
pp. F411-F419 ◽  
Author(s):  
German Lozano ◽  
Ayah Elmaghrabi ◽  
Jordan Salley ◽  
Khurrum Siddique ◽  
Jyothsna Gattineni ◽  
...  

The present study examined whether a prenatal low-protein diet programs a decrease in glomerular filtration rate (GFR) and an increase in systolic blood pressure (BP). In addition, we examined whether altering the postnatal nutritional environment of nursing neonatal rats affected GFR and BP when rats were studied as adults. Pregnant rats were fed a normal (20%) protein diet or a low-protein diet (6%) during the last half of pregnancy until birth, when rats were fed a 20% protein diet. Mature adult rats from the prenatal low-protein group had systolic hypertension and a GFR of 0.38 ± 0.03 versus 0.57 ± 0.05 ml·min−1·100 g body wt−1 in the 20% group ( P < 0.01). In cross-fostering experiments, mothers continued on the same prenatal diet until weaning. Prenatal 6% protein rats cross-fostered to a 20% mother on day 1 of life had a GFR of 0.53 ± 0.05 ml·min−1·100 g body wt−1, which was not different than the 20% group cross-fostered to a different 20% mother (0.45 ± 0.04 ml·min−1·100 g body wt−1). BP in the 6% to 20% group was comparable with the 20% to 20% group. Offspring of rats fed either 20% or 6% protein diets during pregnancy and cross-fostered to a 6% mother had elevated BP but a comparable GFR normalized to body weight as the 20% to 20% control group. Thus, a prenatal low-protein diet causes hypertension and a reduction in GFR in mature adult offspring, which can be modified by postnatal rearing.


1966 ◽  
Vol 44 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Sheila I. Read ◽  
E. J. Middleton ◽  
W. P. Mckinley

Female rats were fed diets low in minerals, vitamins, or protein, or a control diet, both alone and supplemented with 10 parts per million (p.p.m.) parathion for 3 weeks. Male and female rats were fed control and tow-vitamin diets both with and without parathion supplementation (0–10 p.p.m.) for 3 weeks. The liver and kidney carboxylesterases (EC 3.1.1.1.), and the plasma acetylcholinesterases (EC 3.1.1.7.) of the male rats, were measured.In the female rats, a low-mineral diet resulted in an increase of carboxylesterases in the liver and kidney; a low-vitamin diet caused a marked increase in liver carboxylesterases but had no effect on the carboxylesterases of the kidney. Parathion at 10 p.p.m. in all diets greatly reduced the liver carboxylesterases but had less effect on kidney carboxylesterases, except in the case of the low-protein diet, for which the reduction was similar to that in the liver. Varying amounts of parathion added to the low-vitamin diet reduced the liver and kidney carboxylesterases, but to a less extent than when added to the control diet.The liver carboxylesterases of male rats were inhibited approximately 50% by 2 p.p.m. parathion in the control diet and by 4 p.p.m. parathion in the low-vitamin diet. However, inhibition of plasma acetylcholinesterase and kidney carboxylesterases was not marked until the 10 p.p.m. parathion level was fed. The acetylcholinesterase activity of the plasma of male rats did not decrease until the level of liver carboxylesterases was very low.


2008 ◽  
Vol 78 (Suppl_1) ◽  
pp. 200-200
Author(s):  
Chandrasekhar Yallampalli ◽  
Rebakah Elkins ◽  
Uma Yallampalli ◽  
Kunjureddiar Sathishkumar

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1094 ◽  
Author(s):  
Talita de Mello Santos ◽  
Marilia Martins Cavariani ◽  
Dhrielly Natália Pereira ◽  
Bruno César Schimming ◽  
Luiz Gustavo de Almeida Chuffa ◽  
...  

The maternal nutritional status is essential to the health and well-being of the fetus. Maternal protein restriction during the perinatal stage causes sperm alterations in the offspring that are associated with epididymal dysfunctions. Vascular endothelial growth factor (VEGF) and its receptor, VEGFr-2, as well as aquaporins (AQPs) are important regulators of angiogenesis and the epididymal microenvironment and are associated with male fertility. We investigated the effects of maternal protein restriction on epididymal angiogenesis and AQP expression in the early stages of postnatal epididymal development. Pregnant rats were divided into two experimental groups that received either a normoprotein (17% protein) or low-protein diet (6% protein) during gestation and lactation. At postnatal day (PND)7 and PND14, male offspring were euthanized, the epididymides were subjected to morphometric and microvascular density analyses and to VEGF-A, VEGF-r2, AQP1 and AQP9 expression analyses. The maternal low-protein diet decreased AQP9 and VEGFr-2 expression, decreased epididymal microvascularity and altered the morphometric features of the epididymal epithelium; no changes in AQP1 expression were observed at the beginning of postnatal epididymal development. Maternal protein restriction alters microvascularization and affects molecules involved in the epidydimal microenvironment, resulting in morphometric alterations related to a delay in the beginning of epididymis postnatal development.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Victor Dubois-Ferrière ◽  
René Rizzoli ◽  
Patrick Ammann

Low protein intake is associated with an alteration of bone microstructure and material level properties. However, it remains unknown whether these alterations of bone tissue could influence the response to repeated mechanical loading. The authors investigated thein vitroeffect of repeated loading on bone strength in humeri collected from 20 6-month-old female rats pair-fed with a control (15% casein) or an isocaloric low protein (2.5% casein) diet for 10 weeks. Bone specimens were cyclically loaded in three-point bending under load control for 2000 cycles. Humeri were then monotonically loaded to failure. The load-displacement curve of thein vitrocyclically loaded humerus was compared to the contralateral noncyclically loaded humerus and the influence of both protein diets. Material level properties were also evaluated through a nanoindentation test. Cyclic loading decreased postyield load and plastic deflection in rats fed a low protein diet, but not in those on a regular diet. Bone material level properties were altered in rats fed a low protein diet. This suggests that bone biomechanical alterations consequent to cyclic loading are more likely to occur in rats fed a low protein diet than in control animals subjected to the samein vitrocyclic loading regimen.


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