Antibiotics attenuate experimental hypertension in rats

1985 ◽  
Vol 105 (3) ◽  
pp. 347-350 ◽  
Author(s):  
J. W. Honour ◽  
S. P. Borriello ◽  
U. Ganten ◽  
P. Honour

ABSTRACT Hypertension was produced in Sprague–Dawley rats by intramuscular injections of either corticosterone or ACTH. Lower increases in blood pressure to these challenges were observed in Sprague–Dawley rats pretreated with neomycin or vancomycin which alone had no effect on blood pressure or growth. The development of high blood pressure in spontaneously hypertensive rats of a stroke-prone substrain was also attenuated by oral administration of neomycin. These results suggest that experimental hypertension can be modulated by the administration of antibiotics. J. Endocr. (1985) 105, 347–350

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Cameron G McCarthy ◽  
Camilla F Wenceslau ◽  
R. Clinton Webb

Autophagy is the constitutively active catabolic process regulating protein quality control and energy homeostasis. However, dysregulation of this process can have detrimental effects on cellular function. In particular, insufficient autophagy has been proposed as a mechanism of cellular aging, as this leads to the accumulation of damaged macromolecules and organelles. Hypertension is a condition of vascular aging. In fact, many factors that contribute to the deterioration of vascular function as we age are exacerbated in clinical and experimental hypertension. Nonetheless, whether high blood pressure per se is the cause or effect of diminished autophagy remains to be clarified. We hypothesized that mesenteric resistance arteries (MRA) from spontaneously hypertensive rats (SHR) would have decreased autophagic flux as measured by conversion of microtubule-associated protein light chain 3 (LC3-I to LC3-II) compared to normotensive Wistar Kyoto rats (WKY). We observed that MRA from male 12-15 week old SHR have decreased basal expression both cytosolic LC3 (LC3-I) and phosphatidylethanolamine conjugated LC3 (LC3-II), and expression of these proteins are similarly decreased in SHR chronically treated with hydrochlorothiazide and reserpine (SHR+HCTZ/Res) [Arbitrary units (AU), LC3-1: WKY: 1.4±0.1, SHR: 1.1±0.1*, and SHR+HCTZ/Res: 0.7±0.1*; LC3-II: WKY: 1.4±0.1, SHR: 1.1±0.1*, and SHR+HCTZ/Res: 0.7±0.1*, *p<0.05 vs. WKY]. To understand autophagic flux, some MRA were incubated with lysosomal inhibitor chloroquine (CQ; 30 μM) for 2 hours. CQ incubation significantly increased LC3-II expression to a similar magnitude in WKY, SHR, and SHR+HCTZ/Res MRA (all *p<0.05 vs. basal). However, the percent increase in LC3-II expression after CQ incubation was significantly less in SHR compared to WKY, and SHR+HCTZ/Res was not different from either WKY or SHR (% increase from basal LC3-II, WKY: 546±187, SHR: 156±38*, and SHR+HCTZ/Res: 273±106, *p<0.05 vs. WKY). Overall, these data suggest that SHR have impaired autophagosome-lysosomal fusion, and this is not solely attributable to high blood pressure. Therefore, reconstituting autophagic activity could be a novel prophylactic or therapeutic measure against vascular aging in hypertension.


2018 ◽  
Vol 9 (3) ◽  
pp. 1657-1671 ◽  
Author(s):  
Shyan Yea Chay ◽  
Annas Salleh ◽  
Nor Fazila Sulaiman ◽  
Najib Zainal Abidin ◽  
Mohamad Ariff Hanafi ◽  
...  

Winged bean seed hydrolysate is found to reduce blood pressure in spontaneously hypertensive rats. Peptide of non-Current Good Manufacturing Practice grade demonstrates toxicity and is not suitable for testing in animals.


1992 ◽  
Vol 127 (3) ◽  
pp. 258-261 ◽  
Author(s):  
Justicia Opoku ◽  
Mohammed Kalimi

In the present study, we determined the effect of RU 486 on two experimental models of hypertension in the rat, deoxycorticosterone acetate (DOCA)-salt in nephrectomized rats and spontaneously hypertensive rats. Uni-nephrectomized saline-drinking male Sprague-Dawley rats were divided into three groups and each animal was given either 0.2ml olive oil (control), 1 mg DOCA, or 1 mg DOCA +10 mg RU 486 dissolved in 0.2 ml olive oil every third day for a period of three weeks. Within a week of steroid administration, there was a significant increase in the systolic blood pressure (SBP) in the DOCA-salt (157±3.8 mmHg) and DOCA+RU 486 (155±2.1 mmHg) treated rats over the control (116±2.6 mmHg) rats, which remained elevated throughout the experimental period. There was significant increase in the water intake and urine output in DOCA or DOCA+RU 486 treated rats as compared to the control untreated rats. In the experiment involving the spontaneously hypertensive rats, the rats were divided into three groups and each animal given 0.2 ml olive oil (control), 1 mg RU 486, or 5 mg RU 486 dissolved in 0.2 ml olive oil for six weeks. Instead of the expected decrease in the blood pressure, RU 486 significantly elevated blood pressure during the six weeks of drug administration. Water intake, urine output, and weights remained comparable in both groups. We conclude that RU 486 has no effect on the DOCA-salt model of hypertension but, surprisingly, elevates hypertension in the spontaneously hypertensive rats.


1995 ◽  
Vol 6 (4) ◽  
pp. 1209-1215
Author(s):  
Q C Meng ◽  
J Durand ◽  
Y F Chen ◽  
S Oparil

This study used a novel simple method for the extraction, separation, identification, and quantitation of angiotensin-like immunoactivity from tissue to examine the effects of altering dietary NaCl intake on intrarenal angiotensin I, II, and III levels in salt-sensitive, spontaneously hypertensive rats, salt-resistant Wistar-Kyoto rats, and Sprague-Dawley rats. Seven-week-old male spontaneously hypertensive rats, Wistar-Kyoto rats, and Sprague-Dawley rats were assigned randomly to a diet containing either 8% (high) or 1% (basal) salt and were maintained on these diets for 3 wk. Rats were then decapitated without prior anesthesia, and kidneys were rapidly (< 30 s) removed, snap frozen in liquid nitrogen, and stored at -80 degrees C. Frozen tissue was extracted in 2 M acetic acid and then subjected to solid-phase extraction with the cation exchange resin AG 50W X4. Angiotensin peptides were separated by reversed-phase high-performance liquid chromatography on a phenyl silica gel column with an eluent consisting of 20% acetonitrile in 0.1 M ammonium phosphate buffer, pH 4.9, and quantitated by radioimmunoassay. The elution of standard peptides under isocratic conditions revealed clear resolution of angiotensin I, II, and III and the (1-7) and (3-8) peptides. Recoveries of both labeled and unlabeled angiotensin peptide standards from the extraction step were > 90%. Renal angiotensin II stores were significantly higher in spontaneously hypertensive rats than in Wistar-Kyoto or Sprague-Dawley rats, independent of diet. Renal angiotensin II and III were further suppressed during dietary salt supplementation in both salt-resistant strains but not in the spontaneously hypertensive rat. These findings are consistent with an enhanced (compared with Wistar-Kyoto and Sprague-Dawley rats) role for angiotensin II in the kidney of the salt-sensitive, spontaneously hypertensive rat, particularly under conditions of dietary salt supplementation.


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