Antihypertensive treatment in early postnatal life modulates prenatal dietary influences upon blood pressure in the rat

2000 ◽  
Vol 98 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Rachel C. SHERMAN ◽  
Simon C. LANGLEY-EVANS
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Control Diet ◽  
In Utero ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Human Populations ◽  
Postnatal Life ◽  
Blood Pressure Elevation ◽  
Low Protein

Epidemiological evidence from diverse human populations, supported by experimental evidence from animal models, suggests that maternal nutrition during pregnancy is an important fetal programming influence upon cardiovascular disease. Experiments with a low-protein-diet model of rat pregnancy suggest a role for the renin–angiotensin system in the programming mechanism, since fetal undernutrition permanently elevates pulmonary and plasma angiotensin-converting enzyme activity. Long-term beneficial effects of captopril on blood pressure in this model require further investigation in order to clarify the role of angiotensin II. Pregnant rats were fed a control diet containing 18% (w/w) casein as the protein source or a low-protein diet containing 9% (w/w) casein. Between the ages of 2 and 4 weeks postnatally, mothers and their pups were treated with losartan or nifedipine. All pups in the study had blood pressure determined at 4 and 12 weeks of age using a tail cuff. Animals exposed to the low-protein diet in utero and not subjected to drug treatment had elevated blood pressure relative to control rats (mean increase of 27 mmHg; P < 0.001). Treatment of rats exposed to the control diet in utero with either nifedipine or losartan between 2 and 4 weeks of age did not alter their blood pressure. Nifedipine had no effect upon the blood pressure of low-protein-exposed pups, but losartan prevented the blood pressure elevation in these animals. Between 4 and 12 weeks of age, blood pressure increased significantly in all groups (P < 0.001). The pattern of blood pressure among the groups was identical to that observed at 4 weeks, suggesting that the observed early effects of losartan would be maintained into adult life. The data are consistent with the hypothesis that angiotensin II plays a major role in the prenatal programming of hypertension. The action of angiotensin II at the AT1 receptor between 2 and 4 weeks of age may be critically up-regulated by fetal factors, including exposure to glucocorticoids of maternal origin.

Weanling Rats Exposed to Maternal Low-Protein Diets during Discrete Periods of Gestation Exhibit Differing Severity of Hypertension

1996 ◽  
Vol 91 (5) ◽  
pp. 607-615 ◽  
Author(s):  
Simon C. Langley-Evans ◽  
Simon J. M. Welham ◽  
Rachel C. Sherman ◽  
Alan A. Jackson
Keyword(s):  
Blood Pressure ◽  
Control Diet ◽  
Plasma Renin ◽  
Late Gestation ◽  
Protein Diet ◽  
Male Rats ◽  
Low Protein Diet ◽  
Fetal Exposure ◽  
Low Protein ◽  
Protein Diets

1. In the rat, hypertension is induced by fetal exposure to maternal low-protein diets. The effect on blood pressure of undernutrition before conception and during discrete periods in early, mid or late pregnancy was assessed using an 18% casein (control) diet and a 9% casein diet to apply mild protein restriction. 2. The offspring of rats fed 9% casein developed raised blood pressure by weaning age. Feeding a low-protein diet before conception was not a prerequisite for programming of hypertension. 3. Hypertension was observed in rats exposed to low protein during the following gestational periods: days 0–7, days 8–14 and days 15–22. Blood pressure increases elicited by these discrete periods of undernutrition were lower than those induced by feeding a low-protein diet throughout pregnancy. The effect in early gestation was significant only in male animals. Post-natal growth of male rats exposed to low-protein diets was accelerated, but kidneys were small in relation to body weight. 4. Biochemical indices of glucocorticoid action in liver, hippocampus, hypothalamus and lung were elevated in rats exposed to low-protein diets in utero. The apparent hypersensitivity to glucocorticoids was primarily associated with undernutrition in mid to late gestation. 5. Plasma renin activity was elevated in rats exposed to 9% casein over days 15–22 of gestation. Animals undernourished over days 0–7 and 8–14 produced pups with lower plasma angiotensin II concentrations at weaning. 6. Fetal exposure to maternal low-protein diets for any period in gestation may programme hypertension in the rat. Alterations to renal structure, renal hormone action or the hypothalamic—pituitary-adrenal axis may all play a role in the programming phenomenon, either independently or in concert.

Increased systolic blood pressure in rats induced by a maternal low-protein diet is reversed by dietary supplementation with glycine

2002 ◽  
Vol 103 (6) ◽  
pp. 633-639 ◽  
Author(s):  
Alan A. JACKSON ◽  
Rebecca L. DUNN ◽  
Michael C. MARCHAND ◽  
Simon C. LANGLEY-EVANS
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Control Diet ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Cardiovascular Development ◽  
Dietary Nitrogen ◽  
Low Protein ◽  
And Function ◽  
Endogenous Formation

When rat dams consume a diet low in protein during pregnancy, their offspring develop high blood pressure. On a low-protein diet, the endogenous formation of the amino acid glycine is thought to become constrained. Glycine may become conditionally essential, as its rate of endogenous formation is inadequate to meet metabolic needs, and may be limiting for the normal development of the fetus. In the present study, five groups of Wistar rats were provided during pregnancy with one of five diets: a control diet containing 18% (w/w) casein (CON), a low-protein diet containing 9% casein (MLP), or the low-protein diet supplemented with 3% glycine (MLPG), alanine (MLPA) or urea (MLPU). The offspring were weaned on to standard laboratory chow, and blood pressure was measured at 4 weeks of age. Blood pressure was significantly increased in the MLP, MLPA and MLPU groups compared with the CON group, but for the MLPG group blood pressure was not significantly different from CON. Compared with the CON group, body weight was significantly reduced for the MLP, MLPA and MLPG groups, but for the MLPU group body weight was not different from CON. These data show that different forms of non-essential dietary nitrogen, when consumed during pregnancy, exert different effects upon the growth and function of the offspring. The availability of glycine appears to be of critical importance for normal cardiovascular development.

Renal function and angiotensin AT1 receptor expression in young rats following intrauterine exposure to a maternal low-protein diet

2003 ◽  
Vol 104 (6) ◽  
pp. 607-614 ◽  
Author(s):  
Vandana SAHAJPAL ◽  
Nick ASHTON
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Angiotensin Ii ◽  
Filtration Rate ◽  
At1 Receptor ◽  
Receptor Expression ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Kidney Weight ◽  
Low Protein

Recent studies have proposed a link between impaired nephrogenesis, decreased activity of the renin–angiotensin system and the onset of hypertension in rats exposed in the uterus to a maternal low-protein diet. However, there is no detailed information about renal function in this model; hence the aim of the present study was to assess renal function in young (4-week-old) rats exposed in the uterus to a maternal low-protein diet. Pregnant Wistar rats were fed isocalorific diets containing either 18% (normal protein; offspring denoted NP rats) or 9% (low protein; offspring denoted LP rats) (w/w) protein from conception until birth. At 4 weeks of age, male offspring were anaesthetized and prepared for the study of renal function, during which animals received saline alone, a bolus of enalapril (5 mg·kg-1) or a bolus of enalapril followed by an infusion of angiotensin II (30 ng·min-1·kg-1). Under control conditions, renal haemodynamic and tubular function did not differ. However, when challenged with angiotensin II, LP rats responded with a greater decrease in glomerular filtration rate than did NP rats [NP, 2.0±0.2 ml·min-1·g-1 kidney weight (n=9); LP, 1.0±0.2 ml·min-1·g-1 kidney weight (n=5); P<0.05]. Renal electrolyte excretion did not differ. LP rats had significantly fewer glomeruli than NP rats (P<0.01). Renal angiotensin II AT1 receptor expression was increased (P<0.01) by 24% in LP rats. It is concluded that blood pressure may be elevated in LP rats in order to maintain glomerular filtration rate against a background of fewer nephrons. Increased AT1 receptor expression, which may arise as a result of the direct effect of protein restriction or in response to the reported decrease in renal tissue angiotensin II concentration, could also contribute to the elevated blood pressure of this model.

Effect of High-Salt, High-Carbohydrate, Low-Protein Diet on Hypertension in the Rat

1973 ◽  
Vol 45 (s1) ◽  
pp. 99s-102s
Author(s):  
Hideo Ueda
Keyword(s):  
Blood Pressure ◽  
High Protein Diet ◽  
Normal Diet ◽  
High Salt ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Heart Weight ◽  
Hypertensive Rats ◽  
High Carbohydrate ◽  
Low Protein

1. High-salt, high-carbohydrate and low-protein diet induces remarkable elevation of blood pressure in spontaneous hypertensive rats (SHR). 2. These animals have low serum potassium, low blood urea nitrogen and high blood sugar. 3. Heart weight is increased in proportion to the elevation of blood pressure. 4. Kidney weight of rats receiving the high-salt, high-carbohydrate and low-protein diet was, by contrast, smaller than SHR receiving a normal diet. 5. The kidneys of SHR receiving a high-salt, high-protein diet were twice as heavy as the kidneys of normal rats. 6. Similar dietary modifications in Goldblatt hypertensive rats to those in SHR produced similar changes in blood pressure and heart weight.

scholarly journals Pancreatic islet insulin secretion and metabolism in adult rats malnourished during neonatal life

2002 ◽  
Vol 87 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Francisco B. Barbosa ◽  
Kirsten Capito ◽  
Hans Kofod ◽  
Peter Thams
Keyword(s):  
Insulin Secretion ◽  
Control Diet ◽  
Phospholipase A ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Lactation Period ◽  
Adult Rats ◽  
Glycerophosphate Dehydrogenase ◽  
Low Protein ◽  
Protein Group

Pancreatic islets were isolated from rats that had been nursed by dams fed with a control or an 8·7 % protein diet during the first 12 d of the lactation period. Glucose-induced insulin secretion from islets in the 8·7 % protein group was reduced 50 %. The islet insulin and DNA content were similar, whereas the pancreatic insulin content was reduced by 30 % in the rats fed 8·7 % protein. In order to elucidate the mechanism responsible for the attenuation of insulin secretion, measurements were performed of the activity of several islet enzymes that had previously been supposed to be involved in the coupling of glucose stimulation to insulin secretion. Islet glucose oxidation was unaffected, but glucose-stimulated hydrolysis of phosphatidylinositol was reduced by one-third in the islets of rats fed 8·7 % protein. The activity of mitochondrial glycerophosphate dehydrogenase was similar in islets of rats fed the 8·7 % protein diet and those fed the control diet. The activity of Ca-independent phospholipase A2was increased fourfold in the islets of rats fed 8·7 % protein. It is concluded that impairment of glucose-induced insulin secretion in rats fed a low-protein diet may be caused by attenuation of islet phosphatidylinositol hydrolysis, and it is tentatively suggested that the increased activity of Ca-independent phospholipase A2in islets of rats fed a low-protein diet may participate in the stimulation of apoptosis.

Green tea extract intake during lactation modified cardiac macrophage infiltration and AMP-activated protein kinase phosphorylation in weanling rats from undernourished mother during gestation and lactation

2016 ◽  
Vol 8 (2) ◽  
pp. 178-187 ◽  
Author(s):  
E. Matsumoto ◽  
S. Kataoka ◽  
Y. Mukai ◽  
M. Sato ◽  
S. Sato
Keyword(s):  
Protein Kinase ◽  
Green Tea ◽  
Control Diet ◽  
Protein Restriction ◽  
Protein Diet ◽  
Macrophage Infiltration ◽  
Low Protein Diet ◽  
Low Protein ◽  
Tea Extract ◽  
Amp Activated Protein Kinase

Maternal dietary restriction is often associated with cardiovascular disease in offspring. The aim of this study was to investigate the effect of green tea extract (GTE) intake during lactation on macrophage infiltration, and activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and serine-threonine kinase Akt (Akt) in the hearts of weanlings exposed to maternal dietary protein restriction. Pregnant Wistar rats were fed control (C) or low-protein diets (LP) throughout gestation. Following delivery, the dams received a control or a GTE-containing control diet during lactation: control diet during gestation and lactation (CC), low-protein diet during gestation and lactation (LPC), low-protein diet during gestation and 0.12% GTE-containing low-protein diet during lactation (LPL), and low-protein diet during gestation and 0.24% GTE-containing low-protein diet during lactation (LPH). The female offspring were sacrificed at day 22. Biochemical parameters in the plasma, macrophage infiltration, degree of fibrosis and expression levels of AMPK and Akt were examined. The plasma insulin level increased in LPH compared with LPC. Percentage of the fibrotic areas and the number of macrophages in LPC were higher than those in CC. Conversely, the fibrotic areas and the macrophage number in LPH were smaller (21 and 56%, respectively) than those in LPC. The levels of phosphorylated AMPK in LPL and LPH, and Akt in LPH were greater than those in LPC. In conclusion, maternal protein restriction may induce macrophage infiltration and the decrease of insulin levels. However, GTE intake during lactation may suppress macrophage infiltration and restore insulin secretion function via upregulation of AMPK and insulin signaling in weanlings.

Increased NaCl preference of rats fed low-protein diet

1996 ◽  
Vol 270 (6) ◽  
pp. R1189-R1196 ◽  
Author(s):  
A. Okiyama ◽  
K. Torii ◽  
M. G. Tordoff
Keyword(s):  
Control Diet ◽  
Physiological Mechanism ◽  
Plasma Renin ◽  
Calcium Deficiency ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Sodium Balance ◽  
Deficient Diet ◽  
Low Protein

Four studies were conducted to assess the effect of a low-protein diet on NaCl intake. Young rats fed either control (20% casein) or low-protein (5% casein) high-carbohydrate (CHO) diet were allowed to drink either water alone or water and 300 mM NaCl. Relative to rats fed control diet, rats fed the low-protein diet progressively increased NaCl intake so that, despite lower food and water intakes, they drank 180% more NaCl during the last 3 days of the 21-day test. Additional studies found that rats fed low-protein diet always maintained positive sodium balance, were neither sodium depleted nor hypovolemic, and had normal plasma renin activity and aldosterone concentrations. The elevated NaCl intake was not secondary to calcium deficiency and was unaffected by mineral supplementation of the protein-deficient diet. Increases in the diet's CH and/or fat content incidental to decreases in its protein content influenced, but could not completely account for, the effect of protein deficiency on NaCl intake. We conclude that protein deficiency is the primary cause of the elevated NaCl preference produced by being fed a low-protein diet and that a novel physiological mechanism underlies this behavior.

Development of β-cell mass in fetuses of rats deprived of protein and/or energy in last trimester of pregnancy

2002 ◽  
Vol 283 (3) ◽  
pp. R623-R630 ◽  
Author(s):  
Eric Bertin ◽  
Marie-Noëlle Gangnerau ◽  
Georges Bellon ◽  
Danièle Bailbé ◽  
Annick Arbelot De Vacqueur ◽  
...  
Keyword(s):  
Control Diet ◽  
Cell Mass ◽  
Energy Restriction ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Restricted Diet ◽  
Β Cell ◽  
Fetal Plasma ◽  
Low Protein

Fetal malnutrition is now proposed as a risk factor of later obesity and type II diabetes. We previously analyzed the long-term impact of reduced protein and/or energy intake strictly limited to the last week of pregnancy in Wistar rats. Three protocols of gestational malnutrition were used: 1) low-protein isocaloric diet (5 instead of 15%) with pair feeding to the mothers receiving the control diet, 2) restricted diet (50% of control diet), and 3) low protein-restricted diet (50% of low-protein diet). Only isolated protein restriction induced a long-term β-cell mass decrease. In the present study, we used the same protocols of food restriction to analyze their short-term impact (on day 21.5 of pregnancy) on β-cell mass development. A 50% β-cell mass decrease was present in the three restricted groups, but low-protein diet, either associated or not to energy restriction, increased fetal β-cell insulin content. Among all the parameters analyzed to further explain our results, we found that the fetal plasma level of taurine was lowered by low-protein diet and was the main predictor of the fetal plasma insulin level ( r = 0.63, P < 0.01). In conclusion, rat fetuses exposed to protein and/or energy restriction during the third part of pregnancy have a similar dramatic decrease in β-cell mass, and their ability to recover β-cell mass development retardation depends on the type of malnutrition used. Moreover, our results support the hypothesis that taurine might play an important role in fetal β-cell mass function.

THE EFFECT OF PARATHION ON THE LIVER AND KIDNEY CARBOXYLESTERASES AND THE PLASMA ACETYLCHOLINESTERASES OF RATS FED NUTRITIONALLY DEFICIENT DIETS

1966 ◽  
Vol 44 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Sheila I. Read ◽  
E. J. Middleton ◽  
W. P. Mckinley
Keyword(s):  
Control Diet ◽  
Acetylcholinesterase Activity ◽  
Protein Diet ◽  
Female Rats ◽  
Male Rats ◽  
Low Protein Diet ◽  
Male And Female ◽  
Low Protein ◽  
Male And Female Rats ◽  
Liver And Kidney

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.

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