silicon and Hypertension

Vascular aging is characterized by increase in arterial stiffness and remodeling of the arterial wall with a loss of elastic properties. Silicon is an essential trace element highly present in arteries. It is involved in the constitution and stabilization of elastin fibers. The nutritional supply and bioavailability of silicon are often inadequate. Spirulina (Sp), micro algae have recognized nutritional properties and are able to incorporate minerals in a bioavailable form. We evaluated the effects of nutritional supplementation with silicon-enriched spirulina (SpSi) on arterial system structure and function in hypertension. Experiments were performed on hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats supplemented with SpSi or Sp over a period of three months. Arterial pressure, vascular function and morphometric parameters of thoracic aorta were analyzed. SpSi supplementation lowered arterial pressure in SHR and minimized morphometric alterations induced by hypertension. Aortic wall thickness and elastic fibers fragmentation were partially reversed. Collagen and elastin levels were increased in association with extracellular matrix degradation decrease. Vascular reactivity was improved with better contractile and vasorelaxant responses to various agonists. No changes were observed in SHR supplemented with Sp. The beneficial effects of SpSi supplementation evidenced here, may be attributable to Si enrichment and offer interesting opportunities to prevent cardiovascular risks.

Topics: Animals; Antihypertensive Agents; Aorta; Aorta, Thoracic; Arterial Pressure; Biological Availability; Collagen; Dietary Supplements; Elastin; Hypertension; Male; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Silicon; Spirulina

We propose an original method for controlling BP by administration of Si~ODN nanocomposites containing antisense oligonucleotides fixed on silicon-organic nanoparticles. ODN in nanocomposites are targeted to mRNA of the genes encoding angiotensin-converting enzyme (ACE1) and type 1 angiotensin-II receptor (AT1A). The experiments were performed on hypertensive ISIAH rats, a genetic model of hypertension. Single inhalation or intraperitoneal administration of the nanocomposites targeted to ACE1 mRNA or ATA1 mRNA, respectively, led to a pronounced decrease (by ~30 mm Hg) in systolic BP in ISIAH rats over a week. The use of scrambled ODN in the nanocomposites had no effect. A decrease in the expression of ACE1 and AT1A genes under the effect of the corresponding antisense ODN was demonstrated, which attested to directed effect of the test preparations.

Topics: Amino Acid Transport System A; Animals; Blood Pressure; Hypertension; Male; Nanoparticles; Oligonucleotides, Antisense; Peptidyl-Dipeptidase A; Rats; RNA, Messenger; Silicon

In this paper, the poly-Si nanowire sensor was fabricated by top-down technique for sodium chloride concentration measurement. The results showed that the smallest threshold voltage and the best resolution were 1.65 V and 0.41 μM, respectively. Furthermore, the sensor can be reused more than 50 times which maintained acceptable performance and showed good linearity of the calibration within wide range of the concentration. Based on these results, it can be concluded that the proposed sensor has great potential to be used for measuring complicated sample with suitable modification on the surface of nanowires.

Topics: Biosensing Techniques; Calibration; Electrochemistry; Equipment Design; Humans; Hydrogen-Ion Concentration; Hypertension; Ions; Microscopy, Electron, Scanning; Nanowires; Reproducibility of Results; Silicon; Sodium Chloride; Temperature; Time Factors; Transistors, Electronic

Topics: Carbon; Hypertension; Hypertension, Pulmonary; Silicon

Topics: Antihypertensive Agents; Hypertension; Secologanin Tryptamine Alkaloids; Silicon

Topics: Animals; Hypertension; Liver Cirrhosis, Experimental; Portal Pressure; Silicon; Spleen