Post-Weaning Protein Malnutrition Increases Blood Pressure and Induces Endothelial Dysfunctions in Rats

Abstract

Malnutrition during critical periods in early life may increase the subsequent risk of hypertension and metabolic diseases in adulthood, but the underlying mechanisms are still unclear. We aimed to evaluate the effects of post-weaning protein malnutrition on blood pressure and vascular reactivity in aortic rings (conductance artery) and isolated-perfused tail arteries (resistance artery) from control (fed with Labina®) and post-weaning protein malnutrition rats (offspring that received a diet with low protein content for three months). Systolic and diastolic blood pressure and heart rate increased in the post-weaning protein malnutrition rats. In the aortic rings, reactivity to phenylephrine (10−10–3.10−4 M) was similar in both groups. Endothelium removal or L-NAME (10−4 M) incubation increased the response to phenylephrine, but the L-NAME effect was greater in the aortic rings from the post-weaning protein malnutrition rats. The protein expression of the endothelial nitric oxide isoform increased in the aortic rings from the post-weaning protein malnutrition rats. Incubation with apocynin (0.3 mM) reduced the response to phenylephrine in both groups, but this effect was higher in the post-weaning protein malnutrition rats, suggesting an increase of superoxide anion release. In the tail artery of the post-weaning protein malnutrition rats, the vascular reactivity to phenylephrine (0.001–300 µg) and the relaxation to acetylcholine (10−10–10−3 M) were increased. Post-weaning protein malnutrition increases blood pressure and induces vascular dysfunction. Although the vascular reactivity in the aortic rings did not change, an increase in superoxide anion and nitric oxide was observed in the post-weaning protein malnutrition rats. However, in the resistance arteries, the increased vascular reactivity may be a potential mechanism underlying the increased blood pressure observed in this model.

Experimental immunology The effect of vitamin B 6 supplementation of protein deficiency diet on hematological parameters in the blood of rats subjected/non subjected to physical exertion – a pilot study

“…It also affects cardiovascular and immunology system due to endothelial dysfunction, hypertension and anemia syndrome or disturb growth and development of thymus and spleen [3,17,25]. Protect role against protein deficiency in cardiovascular and immune system can play vitamin B 6 .…”

“…Protein deficiency leads to a reduction of muscle growth with a simultaneous decrease in metabolic rate and physical activity. It increases blood pressure which may be associated with endothelial dysfunction and increased sympathetic activity [3]. They also result in disorders in metabolism of lipids and carbohydrates.…”

Increased α1-adrenoreceptor activity is required to sustain blood pressure in female rats under food restriction

“…Furthermore, Tropia and colleagues [40] have shown that protein restricted rats present an increased vascular sympathetic tone [40]. Another study observed endothelial dysfunction with increases in superoxide anion and nitric oxide in these animals [13].…”

Impact of malnutrition on cardiac autonomic modulation in children

“…Other studies 6,7 show increased sympathetic modulation of the autonomic nervous system in malnutrition. Belchior et al 7 analyzed the effect of protein malnutrition in rats and found an increase in blood pressure, however, alterations in vascular reactivity were not found, whereas Sawaya et al 6 found a strong association between malnutrition and hypertension.…”

“…Belchior et al 7 analyzed the effect of protein malnutrition in rats and found an increase in blood pressure, however, alterations in vascular reactivity were not found, whereas Sawaya et al 6 found a strong association between malnutrition and hypertension. These studies suggest possible changes in HRV.…”