Low-protein diet impairs vascular relaxation in virgin and pregnant rats.
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.
Koumentaki
Angeliki
A
Fetal Origins of Adult Disease Research Division, University of Southampton, Obstetrics & Gynaecology (815), Level F, Princess Anne Hospital, Coxford Road, Southampton SO16 5YA, UK.
Anthony
Frederick
F
Poston
Lucilla
L
Wheeler
Timothy
T
D000109:Acetylcholine; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage*; D005314:Embryonic and Fetal Development; D005260:Female; D008638:Mesenteric Arteries / Q000503:physiopathology; D020030:Nitric Oxide Donors; D009929:Organ Size; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology / Q000503:physiopathology*; D011488:Protein Deficiency / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D013096:Spermine; D014664:Vasodilation; D014665:Vasodilator Agents
D004044:Dietary Proteins; D020030:Nitric Oxide Donors; D014665:Vasodilator Agents; D013096:Spermine; D000109:Acetylcholine