THE EFFECT OF OUABAIN ON ALDOSTERONE PRODUCTION IN THE RAT

1971 ◽  
Vol 68 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Kathleen Sz. Szalay
Keyword(s):  
Chronic Treatment ◽  
High Concentration ◽  
Low Concentration ◽  
Aldosterone Production ◽  
The Media ◽  
Renin Content

ABSTRACT Chronic treatment with ouabain increases aldosterone production in the rat but has no effect on the renal renin content. The effect of ouabain in vitro on aldosterone depends on its concentration and the K content of the media: 10−8 m ouabain and 4 and 8 meq./l K and 10−4 m and 4 meq./l K intensify, while 10−3 m at 6 and 8 meq./l K inhibits production. In the present experiments, ouabain at low concentration increased and at high concentration reduced aldosterone production.

Inhibition of prostaglandin effects by ouabain in the canine vascular tissue

1969 ◽  
Vol 47 (10) ◽  
pp. 871-879 ◽  
Author(s):  
D. Kadar ◽  
F. A. Sunahara
Keyword(s):  
Vascular Tissue ◽  
Prostaglandin E ◽  
High Concentration ◽  
Low Concentration ◽  
Mesenteric Vein ◽  
Dependent Atpase ◽  
Prostaglandin F ◽  
The Media ◽  
Spontaneous Contractions ◽  
Dose Dependent

The effects of prostaglandins on the isolated mesenteric vein and artery of the dog were investigated. Prostaglandin E1 (PGE1) inhibited spontaneous contractions of the tissue whereas prostaglandin F1α (PGF1α) and prostaglandin F2α (PGF2α) stimulated them. The effects of prostaglandins were not influenced by pretreatment with atropine, phenoxybenzamine, propranolol, or tetrodotoxin. The norepinephrine-induced contractions were inhibited by PGE1 and enhanced by PGF1α and PGF2α Both these contrasting effects were enhanced in a low concentration of K+ (1.2 mM) and diminished when the media contained K+ in high concentration (23.2 mM). Pretreatment of the tissue with ouabain in sufficiently high concentration (1.5 × 10−5 M) produced an initial contracture followed by relaxation. PGE1 and PGF1α had no effect on the ouabain-treated tissue but PGF2α still induced dose-dependent contractions. In the ouabain-treated tissue the effects of PGE1 and PGF1α on the norepinephrine-induced contraction were also absent. From these experiments it is concluded that the transport enzyme (Na+ + K+)-dependent ATPase is necessary for PGE1 and PGF1α to elicit their action on vascular tissue. The PGF2α effect is probably mediated by an enzyme which is not sensitive to ouabain.

Effects of corticostatin-I on rat adrenal cells in vitro

1990 ◽  
Vol 125 (2) ◽  
pp. 287-292 ◽  
Author(s):  
T. Tominaga ◽  
J. Fukata ◽  
Y. Naito ◽  
Y. Nakai ◽  
S. Funakoshi ◽  
...  
Keyword(s):  
Specific Binding ◽  
Corticosterone Level ◽  
Inhibitory Effect ◽  
Zona Glomerulosa ◽  
Dependent Manner ◽  
Minimum Effective Concentration ◽  
Adrenal Cells ◽  
Aldosterone Production ◽  
The Media

ABSTRACT We have examined the mechanism by which corticostatin-I (CS-I) acts to attenuate ACTH-induced steroidogenesis in rat adrenal cells. CS-I inhibited ACTH-induced corticosterone production in a dosedependent manner, without any effects on the basal corticosterone level in adrenal cells. When the cells were stimulated by 100 pg ACTH/ml, the minimum effective concentration of CS-I was 100 ng/ml, and 0.3–1.0 μg CS-I/ml produced a 50% reduction of the stimulated corticosterone production. The inhibitory effect of CS-I on ACTH-stimulated corticosterone production became apparent within 15 min of incubation, and the effect was reversed quickly by the removal of CS-I from the media. CS-I had no effect on angiotensin II-stimulated aldosterone production by adrenal zona glomerulosa cells. CS-I also did not affect cyclic AMP- or forskolin-stimulated corticosterone production. In an in-vitro binding study using 125I-labelled CS-I, CS-I showed considerable specific binding to rat adrenal cells, and the binding competed with ACTH in a dose-dependent manner. These experiments suggest that CS-I competes with ACTH on their binding sites and exerts an inhibitory effect on the adrenal cells. Journal of Endocrinology (1990) 125, 287–292

Polyethylene glycol diacrylate scaffold filled with cell-laden methacrylamide gelatin/alginate hydrogels used for cartilage repair

2021 ◽  
pp. 088532822110448
Author(s):  
Xiang Zhang ◽  
Zhenhao Yan ◽  
Guotao Guan ◽  
Zijing Lu ◽  
Shujie Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Polyethylene Glycol ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
High Concentration ◽  
Polyethylene Glycol Diacrylate ◽  
Low Concentration ◽  
Glycol Diacrylate

Natural cartilage tissue has excellent mechanical properties and has certain cellular components. At this stage, it is a great challenge to produce cartilage scaffolds with excellent mechanical properties, biocompatibility, and biodegradability. Hydrogels are commonly used in tissue engineering because of their excellent biocompatibility; however, the mechanical properties of commonly used hydrogels are difficult to meet the requirements of making cartilage scaffolds. The mechanical properties of high concentration polyethylene glycol diacrylate (PEGDA) hydrogel are similar to those of natural cartilage, but its biocompatibility is poor. Low concentration hydrogel has better biocompatibility, but its mechanical properties are poor. In this study, two different hydrogels were combined to produce cartilage scaffolds with good mechanical properties and strong biocompatibility. First, the PEGDA grid scaffold was printed with light curing 3D printing technology, and then the low concentration GelMA/Alginate hydrogel with chondral cells was filled into the PEGDA grid scaffold. After a series of cell experiments, the filling hydrogel with the best biocompatibility was screened out, and finally the filled hydrogel with cells and excellent biocompatibility was obtained. Cartilage tissue engineering scaffolds with certain mechanical properties were found to have a tendency of cartilage formation in in vitro culture. Compared with the scaffold obtained by using a single hydrogel, this molding method can produce a tissue engineering scaffold with excellent mechanical properties on the premise of ensuring biocompatibility, which has a certain potential application value in the field of cartilage tissue engineering.

Protective effect of glutathione against oxidative injury in intestinal epithelial cells of piglet in vitro

2009 ◽  
Vol 59 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Qun Chen ◽  
Ying-Qiu Li ◽  
Shu-Ming Zhang ◽  
Hai-Yan Liu
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Oxidative Injury ◽  
Control Group ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
High Concentration ◽  
Low Concentration

AbstractOxidative stress of intestinal epithelium is involved in inflammatory bowel disease. To investigate protective effects of glutathione (GSH) on xanthine/xanthine oxidase (X/XO)-induced oxidative injury in intestinal epithelial cells (IECs). We employed in vitro cell culture supplemented with X/XO. IECs were cultured for 72 h, and then divided into seven groups with various concentrations of X/XO and GSH supplementation in the medium. Agarose gel electrophoresis lanes indicated that X/XO induced DNA injury by the high concentration of XO (40, 70 U/L)-treated groups. The X/XO supplementation significantly increased the production of malondialdehyde (MDA) in a dose-dependent manner. There was a slight increase in total radical-trapping antioxidant potential (TRAP) value by the low concentration of XO (10U/L) alone-treated group (P > 0.05) while supplementation of a high concentration of XO (40, 70 U/L) significantly decreased TRAP value compared with XO (10 U/L) and the control group (P < 0.05). Addition of GSH decreased the production of MDA and DNA fragmentations (P < 0.05), but enhanced TRAP value (P < 0.05). These results suggest that IECs of piglet have the ability of enduring mild oxidative stress induced by a low concentration of XO. Although high concentrations of XO resulted in oxidation injury and lipid peroxidation in the IECs, additions of GSH to the medium showed significant protection against the X/XO-induced oxidative stress.

ALDOSTERONE STIMULATION IN VITRO

1965 ◽  
Vol 48 (2) ◽  
pp. 283-296 ◽  
Author(s):  
Jürg Müller
Keyword(s):  
Adrenal Glands ◽  
High Concentration ◽  
Deficient Diet ◽  
Small Doses ◽  
Aldosterone Production ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Double Isotope ◽  
Very High

ABSTRACT A method is described for assaying aldosterone-stimulating activity in vitro using adrenal glands of rats kept on a sodium deficient diet. The production of aldosterone and corticosterone was measured by double isotope dilution derivative assays. Addition of ACTH or precursor steroids and elevation of the potassium concentration in the incubation medium gave a significant increase of aldosterone production. Angiotensin II showed little aldosterone-stimulating activity and only at a very high concentration. Small doses of a purified extract from human urine lead to a reproducible, significant and dose-dependent increase of aldosterone production without influencing production of corticosterone. The theoretical and practical advantages and limitations of the method are evaluated.

scholarly journals Epilobium angustifolium L.: A medicinal plant with therapeutic properties

2017 ◽  
Vol 1 (2) ◽  
pp. 126-131
Author(s):  
Halyna Ostrovska ◽  
Oleksandra Oleshchuk ◽  
Samuele Vannini ◽  
Samuela Cataldi ◽  
Elisabetta Albi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Medicinal Plant ◽  
Antioxidant Properties ◽  
Carcinoma Cells ◽  
High Concentration ◽  
Mitochondrial Potential ◽  
Low Concentration ◽  
Epilobium Angustifolium ◽  
Human Hepatocellular Carcinoma Cells

Abstract Epilobium angustifolium L. is a medicinal plant belonging to the Onagraceae family, which includes more than 200 different species from all over the world. Traditional medicinal applications include treatment of prostate, gastrointestinal, menstrual disorders and recently it has been used for its analgesic and anti-inflammatory activity. In this investigation E. angustifolium was collected in Ternopil region of Ukraine. The obtained data demonstrated that E. angustifolium herb extract, rich in polyphenolic compounds such as flavonoids and tannins, display high antioxidant properties. In addition the potential anticancer activity has been investigated in vitro on human hepatocellular carcinoma cells (HepG2). Furthermore the cytotoxic and genotoxic effects of E. angustifolium have been investigated respectively by MTT and Comet assay. Results showed that at low concentration, up to 25 μg/mL, the cytotoxic effect was not observed. Increasing concentration from 50 to 75 μg/mL reduced significantly cell viability and induced an important DNA damage in hepatocellular carcinoma. These promising data were also confirmed with mitochondrial potential test. It is possible to conclude that E. angustifolium has beneficial properties in low concentration, in term of antioxidant activity, and it could be a potential antitumoral natural product if it will be used at high concentration

The effect of kinetin on the growth of diploid and autotetraploid root tips of rye in vitro

1970 ◽  
Vol 48 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Da-Ping Yang ◽  
Edward O. Dodson
Keyword(s):  
Secale Cereale ◽  
Linear Growth ◽  
Indoleacetic Acid ◽  
Lateral Roots ◽  
Complete Inhibition ◽  
Root Tips ◽  
High Concentration ◽  
The Media ◽  
Genotypical Difference

Both diploid and autotetraploid root tips of rye, Secale cereale var. Petkus, responded similarly when kinetin and indoleacetic acid (IAA) were added separately to the media in which they were growing. Kinetin retarded the linear growth of the main roots at 1 mg/1 and caused complete inhibition of the initiation of lateral roots; while at 0.1 mg/1, kinetin inhibited the elongation of lateral roots. IAA at 0.1 mg/1 retarded the elongation of main roots, and the initiation and the linear growth of lateral roots. When kinetin and IAA were applied in combination, kinetin was antagonistic to the inhibition caused by a high concentration of IAA in the growth of main roots of tetraploids, but not in the diploid roots.The differential response is considered to be a reflection of their genotypical difference, which may affect the endogenous content or metabolism of these phytohormones of the roots.

scholarly journals The bacteriostatic effect and mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro

2019 ◽  
Author(s):  
Lei Wang ◽  
Fangfang Zhou ◽  
Minyi Xu ◽  
Wei Gong ◽  
Shuiying Ji
Keyword(s):  
Cell Wall ◽  
Rna Sequencing ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Control Group ◽  
High Concentration ◽  
Bacteriostatic Effect ◽  
Low Concentration ◽  
Kinetics Of

Abstract Background: To observe the bacteriostatic effect of berberine on MRSA, while also exploring the bacteriostatic mechanism of BBR on MRSA. Methods: The MIC of BBR, gentamicin, levofloxacin，amikacin was determined by broth microdilution, while the MICs of BBR combined with gentamicin, levofloxacin，amikacin against MRSA were determined using microdilution checkerboard. Time-killing test were used to determine the kinetics of BBR combined with antibiotics for MRSA. We used conductivity to assess the changes in membrane permeability in response to BBR on MRSA, while also investigating the changes in MRSA morphology by TEM. RNA-sequencing was used to analyze the expression of differentially expressed genes in USA300 after its treatment with BBR. Results: The MICs range of BBR on MRSA was 32-256 µg/mL. The range of FICIs of BBR combined with gentamicin, levofloxacin，amikacin were 0.53-1.06, 0.62-1.5, 0.16-1.25. After co-culturing MRSA with BBR at 512 ug/mL, 64 ug/mL,8 ug/mL, respectively, the conductivity of these group increased by 8.14%,13.08% and 12.01%, respectively. Using TEM, we found that low-concentration of BBR had no significant effect on MRSA structure, medium-concentration of BBR thinned the cell wall of MRSA, while high-concentration of BBR destroyed cell wall, leading to bacterial lysis. RNA-sequencing results showed that there were 754 differentially expressed genes in the high-concentration group compared with the control group, of which 561 genes were up-regulated and 193 genes were down-regulated. Compared with the low-concentration group, there were 590 differentially expressed genes, of which 402 genes were up-regulated and 188 genes were down-regulated. Compared with the control group, 19 genes were differentially expressed in the low-concentration group, of which 11 genes were up-regulated,8 genes were down-regulated. Conclusions: BBR displayed an excellent bacteriostatic effect on MRSA. BBR combined with antibiotics significantly enhanced the bacteriostatic effect on MRSA. BBR inhibited bacteria by destroying the structure of cell wall. RNA-sequencing results demonstrated that the expression of cell wall hydrolysis genes and virulence factor were significantly differentially expressed on MRSA.

scholarly journals Effect of exogenous abscisic acid on accumulation of raffinose family oligosaccharides and galactosyl cyclitols in tiny vetch seeds (Vicia hirsuta [L.] S.F. Gray)

2011 ◽  
Vol 73 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Lesław B. Lahuta ◽  
Ryszard J. Górecki ◽  
Ewa Gojło ◽  
Marcin Horbowicz
Keyword(s):  
Abscisic Acid ◽  
Seed Development ◽  
Acid Concentration ◽  
Raffinose Family Oligosaccharides ◽  
High Concentration ◽  
Low Concentration ◽  
Vicia Hirsuta ◽  
Galactosyl Cyclitols

The role of the abscisic acid (ABA) in biosynthesis of raffinose family oligosaccharides (RFOs) and galactosyl cyclitols (Gal-C) in tiny vetch (<em>Vicia hirsuta</em> [L.] S.F. Gray) seeds was investigated. The ABA was applied through incubation of seed at various stage of its development. The level of RFOs and Gal-C was determined in seed maturing on plant and in seed maturing in vitro. In early stages of <em>V. hirsuta</em> seed development, the ABA activated the biosynthesis of galactinol, although the level of arisen galactinol quickly declined. In the later stages of <em>V. hirsuta</em> seed development ABA had stimulatory effect of RFOs and Gal-C biosynthesis. Influence of ABA on biosynthesis of a-galactosides in <em>Vicia hirsuta</em> seed seems to be dependent on abscisic acid concentration. Low concentration of ABA had stimulatory effect on a-galactosides biosynthesis, but high concentration of ABA inhibited the process.

scholarly journals Size Distribution of Colistin Delivery by Different Type Nebulizers and Concentrations During Mechanical Ventilation

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 459 ◽  
Author(s):  
Ching-Yi Liu ◽  
Hsin-Kuo Ko ◽  
James Fink ◽  
Gwo-Hwa Wan ◽  
Chung-Chi Huang ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Size Distribution ◽  
Mechanical Ventilators ◽  
High Concentration ◽  
Low Concentration ◽  
Dose Volume ◽  
Jet Nebulizer ◽  
Similar Range ◽  
Colistin Methanesulfonate

Although aerosol delivery through mechanical ventilators has been used to administer various medications, little is known of administration with colistin. This in vitro evaluation aimed to evaluate size distribution of colistin delivery by different types of nebulizers and concentrations during mechanical ventilation. Colistin methanesulfonate (colistin) for injection was dissolved in 6 mL of distilled water to produce a low concentration (L; 156 mg) and a high concentration (H; 312 mg). A dose volume of 6 mL was placed in a vibrating mesh nebulizer (VMN) and a jet nebulizer (JN). The inhaled mass (mean ± SD) of the VMN-L (53.80 ± 14.79 mg) was greater than both the JN-L (19.82 ± 3.34 mg, P = 0.001) and JN-H (31.72 ± 4.48 mg, P = 0.017). The nebulization time of the VMN-L (42.35 ± 2.30 min) was two times longer than the JN-L (21.12 ± 0.8 min) or JN-H (21.65 ± 0.42 min; P < 0.001). The mass median aerodynamic distal to the endotracheal tube was within a similar range at 2.03 to 2.26 μm (P = 0.434), independent of neb or formulation concentration. In conclusion, the VMN-L yields greater inhaled mass than the JN with either concentration. Therefore, a standard nominal dose of colistin results in a higher delivered dose during mechanical ventilation with a VMN compared with a JN and may be considered the preferred device. If JN must be used, multiple doses of low concentration colistin may compensate for poor delivery performance.

Sign in / Sign up

Export Citation Format

Share Document