Effects of L-arginine oral supplements in pregnant spontaneously hypertensive rats

PURPOSE: To evaluate the effects of L-arginine oral supplementation in spontaneously hypertensive pregnant rats (SHR). METHODS: Thirty SHR and ten Wistar-EPM-1 virgin female rats were used in the study. Before randomization, females were caged with males of the same strain (3:1). Pregnancy was confirmed by sperm-positive vaginal smear (Day 0). Wistar-EPM-1 rats served as counterpart control (C-1). SHR rats were randomized in 4 groups (n=10): Group Control 2, non-treated rats; Group L-Arginine treated with L-arginine 2%; Group Alpha-methyldopa treated with Alpha-methyldopa 33mg/Kg; Group L-Arginine+Alpha-methyldopa treated with L-arginine 2%+Alpha-methyldopa 33mg/Kg. L-arginine 2% solution was offered ad libitum in drinking water and Alpha-methyldopa was administered by gavage twice a day during the length of pregnancy (20 days). Blood pressure was measured by tailcuff plethysmography on days 0 and 20. Body weight was measured on days 0, 10 and 20. Results were expressed as mean ± SD (Standard Deviation). One-Way ANOVA/Tukey (or Kruskal-Wallis/Dunn, as appropriate) was used for group comparisons. Statistical significance was accepted as p<0.05. RESULTS: There was no significant weight gain in isolated L-arginine treated SHR. Mean blood pressure decreased in L-arginine-treated SLR compared with untreated-SHR rats. CONCLUSION: L-arginine oral supplementation reduces blood pressure in spontaneously hypertensive rats during pregnancy.

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Effect of a methionine-supplemented diet on the blood pressure of Wistar–Kyoto and spontaneously hypertensive rats

British Journal Of Nutrition ◽

10.1079/bjn2002810 ◽

2003 ◽

Vol 89 (4) ◽

pp. 539-548 ◽

Cited By ~ 11

Author(s):

Sophie Robin ◽

Véronique Maupoil ◽

Frédérique Groubatch ◽

Pascal Laurant ◽

Alain Jacqueson ◽

...

Keyword(s):

Blood Pressure ◽

Spontaneously Hypertensive Rats ◽

Plasma Homocysteine ◽

Shr Rats ◽

Hypertensive Rats ◽

Spontaneously Hypertensive ◽

Wky Rats ◽

Complex Interactions ◽

Methionine Concentration ◽

Wistar Kyoto

The objectives of the present work were to evaluate the effect of a methionine-supplemented diet as a model of hyperhomocysteinaemia on the systolic blood pressure (BP) and vasomotor functions of aortic rings in Wistar–Kyoto (WKY) and spontaneously hypertensive rats (SHR). WKY and SHR rats, randomised into four groups, were fed a normal semisynthetic diet or a methionine (8 g/kg)-supplemented diet for 10 weeks. Systolic BP was measured non-invasively. At the end of the experiment, plasma homocysteine, methionine, cysteine and glutathione levels were determined. Vasoconstriction and vasodilatation of aortic rings were measured. The methionine-supplemented diet induced a significant increase in plasma homocysteine and methionine concentration in both WKY and SHR rats, an increase in plasma cysteine concentrations in WKY rats and an increase in the glutathione concentration in SHR. The systolic BP of WKY rats fed the methionine-supplemented diet increased significantly (P<0·01), whereas systolic BP was reduced in SHR. An enhanced aortic responsiveness to noradrenaline and a decreased relaxation induced by acetylcholine and bradykinin were observed in the WKY rats fed the methionine-enriched diet. In SHR, the bradykinin-induced relaxation was reduced, but the sodium nitroprusside response was increased. In conclusion, a methionine-enriched diet induced a moderate hyperhomocysteinaemia and an elevated systolic BP in WKY rats that was consistent with the observed endothelial dysfunction. In SHR, discrepancies between the decreased systolic BP and the vascular alterations suggest more complex interactions of the methionine-enriched diet on the systolic BP. Further investigations are needed to understand the paradoxical effect of a methionine-rich diet on systolic BP.

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Effects of hypertension on maternal adaptations to pregnancy: experimental study on spontaneously hypertensive rats

Sao Paulo Medical Journal ◽

10.1590/s1516-31802001000200003 ◽

2001 ◽

Vol 119 (2) ◽

pp. 54-58 ◽

Cited By ~ 7

Author(s):

José Carlos Peraçoli ◽

Marilza Vieira Cunha Rudge ◽

Maria Salete Sartori ◽

Roberto Jorge da Silva Franco

Keyword(s):

Blood Pressure ◽

Weight Gain ◽

Spontaneously Hypertensive Rats ◽

Sodium Retention ◽

Shr Rats ◽

Hypertensive Rats ◽

Spontaneously Hypertensive ◽

Wky Rats ◽

Wistar Kyoto ◽

Tail Cuff

CONTEXT: Animal models for essential hypertension have been used for understanding the human pathological conditions observed in pregnant hypertensive women. OBJECTIVE: To study the possible effects of pregnancy on hypertension and of hypertension on pregnancy in spontaneously hypertensive rats (SHR), and in their normotensive Wistar-Kyoto (WKY) counterparts. TYPE OF STUDY: Comparative study using laboratory animals. SETTING: Animal Research Laboratory of Clinical Medicine at the Medical School of Botucatu, São Paulo State University, Brazil. SAMPLE: Ten to twelve-week-old virgin female normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The animals were separated into four groups: 15 pregnant spontaneously hypertensive rats (SHR-P), 10 non-pregnant spontaneously hypertensive rats (SHR-NP), 15 pregnant normotensive rats (WKY-P), and 10 non-pregnant normotensive rats (WKY-NP). MAIN MEASUREMENTS: The blood pressure was evaluated by the tail cuff method, in rats either with or without prior training for the handling necessary for tail cuff measurements. The maternal volemia expansion was indirectly evaluated by weight gain, and by systemic parameters as hematocrit, hemoglobin, total protein, albumin and sodium retention. The perinatal outcome of pregnancy was evaluated by analysis of resorptions, litter size, rate of low weight and number of stillbirths. RESULTS: The late fall in blood pressure in the pregnant SHR strain and in the normotensive WKY strain can only be detected in rats previously trained to accept the handling necessary for the tail cuff measurement. During pregnancy the body weight gain was significantly higher in WKY than in SHR rats. Systemic parameters were significantly lower in pregnant WKY rats than in non-pregnant WKY rats, while no differences were observed between pregnant and non-pregnant SHR groups. In pregnant WKY rats the sodium retention was higher from the 13th day onwards, while in SHR rats this occurred only on the 21st day. The characteristics of reproductive function such as number and weight of fetus, perinatal mortality and the resorption rate were significantly affected in the SHR strain. CONCLUSION: The SHR strain may be considered as a model for chronic hypovolemic maternal hypertension, with the fetal growth retardation being determined by this hypovolemic state.

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Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities ofEisenia fetidaExtract in Spontaneously Hypertensive Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/349721 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Shumei Mao ◽

Chengde Li

Keyword(s):

Blood Pressure ◽

Inhibitory Activity ◽

Spontaneously Hypertensive Rats ◽

Ang Ii ◽

Shr Rats ◽

Hypertensive Rats ◽

Ace Inhibitory Activity ◽

Spontaneously Hypertensive ◽

Ace Inhibitory

Objectives. This study aimed to investigate the antihypertensive effects of anEisenia fetidaextract (EFE) and its possible mechanisms in spontaneously hypertensive rats (SHR rats).Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats) were used in this study. Rats were, respectively, given EFE (EFE group), captopril (captopril group), or phosphate-buffered saline (PBS) (normal control group and SHR group) for 4 weeks. ACE inhibitory activity of EFEin vitrowas determined. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II), aldosterone (Ald), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) in plasma were determined by radioimmunoassay, and serum nitric oxide (NO) concentration was measured by Griess reagent systems.Results. EFE had marked ACE inhibitory activityin vitro(IC50= 2.5 mg/mL). After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1αand NO than the SHR rats in SHR group.Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity.

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