Amiloride-Sensitive Sodium Flux and Potentials in Perfused Carcinus Gill: Preparations

1986 ◽  
Vol 122 (1) ◽  
pp. 25-35
Author(s):  
ČEDOMIL LUCU ◽  
DIETRICH SIEBERS

Sodium and chloride fluxes, as well as transbranchial potentials (TBP) were studied in isolated perfused gill filaments of the crab Carcinus mediterraneus. Experiments were carried out in media that were either hyposmotic to the perfusion solution (asymmetrical conditions) or isosmotic (symmetrical conditions). Fluxes were found to be diffusional in gills under asymmetrical conditions; amiloride induced an inhibitory effect on influxes, without affecting TBP. Under symmetrical conditions, TBP was −7.6±2.3mV, suggesting that the electrogenic ion pump contributes significantly to the development of TBP. Immediately after addition of 2.5 × 10−4 moll−1 amiloride to the external solution, sodium influxes were reduced to 31% of those in the control group, and TBP was significantly hyperpolarized from −7.6 to −14.8 mV. The absence of Ca2+ under symmetrical conditions diminished TBP hyperpolarization. Half-maximal inhibition of sodium influxes by amiloride was at 7 × 10−5 moll−1. This low amiloride affinity is typical of low resistance leaky epithelia. Sodium transport is discussed as an amiloride-affected influx, probably as a Na/H antiport.

1995 ◽  
Vol 73 (05) ◽  
pp. 798-804 ◽  
Author(s):  
Inger Schousboe ◽  
Margit Søe Rasmussen

SummaryLupus anticoagulants are a group of antibodies commonly found in patients with autoimmune diseases such as systemic lupus erythematosus. Lupus anticoagulants inhibit phospholipid dependent coagulation and may bind to negatively charged phospholipids. Recent studies have suggested an association between anti-β2-glycoprotein I and a lupus anticoagulant, whose activity is frequently dependent on the presence of β2-glycoprotein I. Based on these observations, the effect of anti-β2-glycoprotein I on the autoactivation of factor XII in plasma was investigated. Autoactivation initiated by the presence of negatively charged phospholipids, but not by sulfatide, was strongly inhibited by immunoaffinity purified anti-β2-glycoprotein I. The dose-response curve of anti-β2-gly coprotein I was identical with that of a precipitating antibody, showing no inhibition at low and high antibody dilutions and maximal inhibition at an intermediate dilution. At high antibody concentrations, an increased rate of factor Xlla activation was observed. This increase was of the same magnitude as the decreased rate observed in plasma supplemented with the same amount of β2-glycoprotein I as in the plasma itself. This confirms the inhibitory effect of β2-GP-I on the contact activation and shows that inhibition is effective on the autoactivation of factor XII in plasma. The inhibitory action of β2-glycoprotein I was independent of the inhibition caused by the anti- β2-glycoprotein I/β2-glycoprotein I complex suggesting a synchronized inhibition of factor XII autoactivation by β2-glycoprotein I and anti-β2-gly coprotein I. The inhibition caused by the antibody is suggested to be caused by a reduced availability of negatively charged phospholipids due to the binding of the anti-β2- GP-I/β2-GP-I complex. This complex may be a lupus anticoagulant.


1981 ◽  
Vol 96 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Mridula Chowdhury ◽  
Robert Tcholakian ◽  
Emil Steinberger

Abstract. It has been suggested that treatment of intact male rats with oestradiol benzoate (OeB) causes an interference with testosterone (T) production by the testes by a direct inhibitory effect on steroidogenesis. To test this hypothesis, different doses (5, 10 or 25 IU) of hCG were administered concomitantly with 50 μg of OeB to adult intact or hypophysectomized male rats. The testicular and plasma testosterone, and serum hCG levels were determined. The sex accessory weights were recorded. In the intact OeB-treated group of animals, hCG stimulated both the secondary sex organs and plasma testosterone levels above the intact control group. However, in hypophysectomized animals, although plasma testosterone levels increased above that of intact controls, their secondary sex organ weights did not. Moreover, inspite of high circulating hCG levels, the testicular testosterone content and concentration remained suppressed in OeB-treated animals. The reason for such dichotomy of hCG action on OeB-treated animals is not clear at present.


2019 ◽  
Vol 16 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Hamid Farhang ◽  
Laleh Sharifi ◽  
Mohammad Mehdi Soltan Dallal ◽  
Mona Moshiri ◽  
Zahra Norouzbabaie ◽  
...  

Background: The non-steroidal anti-inflammatory drugs (NSAIDs) play crucial role in the controlling of inflammatory diseases. Due to the vast side effects of NSAIDs, its use is limited. G2013 or &amp;#945;-L-Guluronic Acid is a new NSAID with immunomodulatory features. Objectives: Considering the leading role of TLRs in inflammatory responses, in this study, we aimed to evaluate G2013 cytotoxicity and its effect on the expression of TLR2 and TLR4 molecules. Methods: HEK293-TLR2 and HEK293-TLR4 cells were cultured and seeded on 96-well cell plate, and MTT assay was performed for detecting the viability of the cells after treatment with different concentrations of G2013. HT29 cells were grown and treated with low and high doses of G2013. After total RNA extraction and cDNA synthesis, quantitative real-time PCR were performed to assess the TLR2 and TLR4 mRNA synthesis. Results: We found that concentrations of ≤125 &amp;#181;g/ml of G2013 had no apparent cytotoxicity effect on the HEK293-TLR2 and -TLR4 cells. Our results indicated that after G2013 treatment (5 &amp;#181;g/ml) in HT29 cells, TLR2 and TLR4 mRNA expression decreased significantly compared with the untreated control group (p=0.02 and p=0.001 respectively). Conclusion: The results of this study revealed that G2013 can down regulate the TLR2 and TLR4 gene expression and exerts its inhibitory effect. Our findings are parallel to our previous finding which showed G2013 ability to down regulate the signaling pathway of TLRs. However, further studies are needed to identify the molecular mechanism of G2013.<p&gt;


2020 ◽  
Vol 20 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Lima Asgharpour Sarouey ◽  
Parvaneh Rahimi-Moghaddam ◽  
Fatemeh Tabatabaie ◽  
Khadijeh Khanaliha

: As an important global disease, cutaneous leishmaniasis is associated with complications such as secondary infections and atrophic scars. The first line treatment with antimonials is expensive and reported to have serious side effects and enhance resistance development. The main objective of this study was to evaluate the effect of Cinnarizine on standard strains of Leishmania major because of paucity of information on this subject. Methods: In this experimental study, four concentrations of the drug (5, 10, 15 and 20 μg/ml) were added to Leishmania major cultures at 24, 48 and 72 hours intervals. MTT assays were performed to determine parasite viability and drug toxicity. Leishmania major promastigotes were augmented to the in vitro cultured macrophages (J774 cells) and then incubated for 72 hours. Half maximal inhibitory concentration (IC50) was ascertained by counting parasites. The inhibitory effect of the drug was compared with that of Glucantime. Flow-cytometry was performed to investigate apoptosis. Each test was repeated thrice. Results: The IC50 values of Cinnarizine after 72 hours were calculated to be 34.76 μg/ml and 23.73 μg/ml for promastigotes and amastigotes, respectively. The results of MTT assays showed 48 % promastigote viability after 72 hour-exposure to Cinnarizine at 20 μg/ml concentration. Programmed cell death in promastigote- and amastigote-infected macrophages was quantified to be 13.66 % and 98.7 %, respectively. Flow- cytometry analysis indicated that Cinnarizine induced early and late apoptosis in parasites. All treatments produced results which differed significantly from control group (P<0.05). Conclusion: Cinnarizine showed low toxicity with anti-leishmanial and apoptosis effects on both promastigote and intracellular amastigote forms. Therefore, we may suggest further assessment on animal models of this drug as candidates for cutaneous leishmaniasis therapy.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jun Ma ◽  
Xiankun Zeng ◽  
Min Zhou ◽  
Le Cheng ◽  
Difeng Ren

AbstractSpirulina platensis protein hydrolysates were prepared by digesting protein extracts with papain, and the hydrolysates were separated into 30, 10, and 3 kDa weights using membrane ultrafiltration. The 0–3 kDa low-molecular-weight Spirulina peptides (LMWSPs) proved the highest chemical antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, hydroxyl radical (·OH) scavenging activities and total antioxidant capacity. Cellular antioxidant ability of LMWPs fractions against 2000 μg/mL H2O2 induced oxidative damage of L02 cells were investigated. The MTT assay results displayed that LMWSPs at different concentrations (0–1000 μg/mL) had proliferation effect on the L02 cells and that treatment of the L02 cells with the 1000 μg/mL LMWSPs (0–3 kDa) significantly prevented H2O2-induced oxidative damage compared with control cells. Moreover, the 2′,7′-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe assay showed that the levels of ROS and NO were significantly lower in the experimental group that was treated with the peptides for 24 h than in the control group. Furthermore, using the corresponding kits, the treatment inhibited the reduction of SOD activity and the increase of MDA contents in the L02 cells. Therefore, LMWSPs (0–3 kDa) may have potential applications in antioxidant and liver health products.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ana Carolina Lupepsa ◽  
Paula Vargas-Sanchez ◽  
Marcella Goetz Moro ◽  
Leomar Emanuel Almeida Mecca ◽  
Marcela Claudino ◽  
...  

Abstract Background Several drugs are capable of promoting changes in bone metabolism. The aim of this study was to evaluate the effect of long-term low-dose aspirin (LDA) therapy on implant osseointegration. Methods Male Wistar rats were divided into 4 groups (n = 8/group) according to oral gavage solution received prior (42 days) to the implant surgery on the tibia. The control group was treated with saline solution for 7 (CG-7) and 28 (CG-28) days. The use of low-dose aspirin was performed in AG groups (6.75 mg/kg of aspirin) for 7 (AG-7) and 28 (AG-28) days. After experimental periods, histomorphometric evaluation of bone-to-implant contact (BIC) and the bone area between threads (BABT) was performed. Results Reduced BIC values were detected in AG-7 (62.8% ± 17.1) group compared to AG-28 (91.9% ± 5.4), CG-7 (82.7% ± 15.2), and CG-28 (89.9% ± 9.7). BABT evaluation revealed lower values in AG-7 (70.9% ± 15.2) compared to AG-28 (95.4% ± 3.7) and CG-28 (87.1% ± 10.2) groups. Conclusions The treatment with low doses of aspirin promoted a discrete inhibitory effect in the early stages (7 days) of repair after implant placement, specifically in the bone deposition. However, these effects were not detected in the late stages (28 days), considering BIC and BABT parameters.


2021 ◽  
Vol 42 (1) ◽  
pp. 25-30
Author(s):  
I.M. Ado ◽  
Z.A. Ali ◽  
M.M. Dogara ◽  
K. Abdullahi ◽  
S.A Luka ◽  
...  

The search for bioactive plants which can be used as non-conventional anthelmintics has received considerable attention in recent times because of the increasing, worldwide development of resistance to synthetic anthelminthes worm populations. However, scientific evidence to validate the use of raw plants materials remain limited. This study evaluated the mortality and inhibitory effects of the crude aqueous and methanolic extract of Artemisia annua L. against the shedding of cercariae of Schistosoma mansoni from Biomphalaria pfeifferi. The phytochemical screening of the plant was done using standard procedure, after which the mortality effects of the plant extracts and effects on the shedding of cercariae from B. pfeifferi snails were assessed for 24 hour of exposure. Methanolic extract with the highest concentration of 1.77mg/µL had an inhibitory effect of 63.06±1.84 while the least concentration with 0.12mg/µL had 22.41±2.17 inhibitory effect. For the aqueous extract, the highest concentration with 2.73mg/µL had an inhibitory effect of  55.75±1.94 while the least concentration of 0.23mg/µL had 21.80±1.45. Inhibitory effect of cercariae in the snail vector was  concentration dependent, and there was significance difference (P<0.05) between the treatment mean when compared with the control group. This study has shown that this plant material has some inhibitory effect on the shedding of of S. mansoni cercariae and toxicityeffect on the B. pfeifferisnails, and can therefore be used for the control of the disease causing agent as well as the vector. Keywords: Artemisia annua, Inhibitory effects, cercariae, Biomphalaria pfeifferi


2002 ◽  
Vol 65 (1) ◽  
pp. 153-160 ◽  
Author(s):  
HIROSHI KANO ◽  
TSUTOMU KANEKO ◽  
SHUICHI KAMINOGAWA

Oral intake of some lactic acid bacteria can have beneficial effects on the host by activating immune responses and enhancing resistance to infection by pathogens. In this study, effects of Lactobacillus sp. on the development of autoimmune disease were examined in mice with collagen-induced arthritis (CIA). CIA, a model of some types of rheumatoid arthritis (RA), can be induced in DBA/1J mice by immunizing them with bovine type II collagen (bCII). Oral intake of skimmed milk (SM) fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 (SM/OLL1073R-1) was found to markedly inhibit the development of CIA in these mice, compared with a control group fed the control foodstuff. The inhibitory effect of SM fermented with L. delbrueckii subsp. bulgaricus OLL1102 (SM/OLL1102) or fresh SM was weaker than that of SM/OLL1073R-1. A deMan Rogosa Sharpe (MRS) broth culture of OLL1073R-1 without any major components of SM had the same inhibitory effect as SM/OLL1073R-1, suggesting that the inhibitory effect of SM/OLL1073R-1 is attributable not only to SM components but also to OLL1073R-1 cells, their metabolites, or both. We found that SM/OLL1073R-1 and SM caused reduced secretion of the cytokine IFN-γ by lymph node cells (LNCs) in response to bCII. However, SM/OLL1102 did not affect the secretion of IFN-γ. A polysaccharide fraction secreted by OLL1073R-1 also exhibited the inhibitory effects on both development of CIA and secretion of IFN-γ.


1996 ◽  
Vol 24 (4) ◽  
pp. 358-362 ◽  
Author(s):  
K Kanayama ◽  
H Osada ◽  
K Nariai ◽  
T Endo

The dose-response relationship for the inhibitory effect of indomethacin on implantation and continuance of pregnancy was examined in four groups of rabbits administered with indomethacin (2.5, 5.0, 7.5 and 10.0 mg/kg) during the implantation period and compared with a control group. Implanted fetuses and corpora lutea were counted by laparotomy, and the number of offspring born was noted. The inhibitory effect of indomethacin on implantation was found to be dose–dependent, and the birth rate decreased in the indomethacin groups compared with the control group. As a result, even where implantation had been achieved, death of the implanted fetuses occurred at a high rate in rabbits administered with indomethacin during the implantation period.


e-GIGI ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 238
Author(s):  
Stevia E. Nonutu ◽  
Damajanty H. C. Pangemanan ◽  
Christy N. Mintjelungan

Abstract: One of the treatment options of periodontal abscess caused by Fusobacterium nucleatum is administration of antibiotics. However, long-term antibiotics consumption can cause negative side effects. Therefore, alternative treatments that have low side effects and easy to be obtained are needed. Nike fish (Awaous melanocephalus) is one of the endemic fish of North Sulawesi province which has antibacterial properties. This study was aimed to evaluate the inhibition effect of nike fish extract on the growth of Fusobacterium nucleatum. This was a true experimental study with a posttest only control group design. We used modified Kirby-Bauer method with filter papers. Ciprofloxacin was used as the positive control and aquadest as the negative control. Extract of nike fish and stock of pure bacteria Fusobacterium nucleatum were prepared. The results showed that the average diameters of the inhibition zones formed in the nike fish extract after three repetitions, were as follows: for extract concentration of 12.5% was 2.91 mm; 25% was 4.16 mm; 50% was 8.41 mm; and 100% was 9.58 mm. In conclusion, nike fish extract (Awaous melanocephalus) at concentrations of 50% and 100% had a weak inhibitory effect (Himedia category) on the growth of Fusobacterium nucleatum meanwhile at concentrations of 12.5% and 25% there was no activity of zone of inhibition.Keywords: extract of nike fish (Awaous melanocephalus); Fusobacterium nucleatum; inhibitory effect Abstrak: Salah satu opsi pengobatan abses periodontal yang disebabkan oleh bakteri Fusobacterium nucleatum yaitu dengan penggunaan antibiotik namun mengonsumsi antibiotik jangka panjang dapat menimbulkan efek samping negatif. Oleh karena itu, diperlukan pengobatan alternatif yang memiliki efek samping rendah serta mudah didapat. Ikan nike merupakan salah satu ikan endemik Provinsi Sulawesi Utara yang berkhasiat sebagai antibakteri. Penelitian ini bertujuan untuk mengetahui daya hambat ekstrak ikan nike (Awaous melanocephalus) terhadap pertumbuhan bakteri Fusobacterium nucleatum. Jenis penelitian ialah eksperimental murni dengan post test only control group design. Metode yang digunakan yaitu metode modifikasi Kirby-Bauer dengan menggunakan paper disk. Kontrol positif menggunakan antibakteri ciprofloxacin dan kontrol negatif menggunakan akuades. Pada penelitian ini digunakan ekstrak ikan nike dan stok bakteri murni Fusobacterium nucleatum. Hasil penelitian menunjukkan bahwa rerata diameter zona hambat yang terbentuk pada ekstrak ikan nike setelah tiga kali pengulangan yaitu untuk konsentrasi 12,5% sebesar 2,91 mm; 25% sebesar 4,16 mm; 50% sebesar 8,41 mm; dan 100% sebesar 9,58 mm. Simpulan penelitian ini ialah ekstrak ikan nike (Awaous melanocephalus) pada konsentrasi 50% dan 100% memiliki daya hambat kategori lemah (Himedia) terhadap pertumbuhan bakteri Fusobacterium nucleatum sedangkan pada konsentrasi 12,5% dan 25% dikategorikan tidak terdapat aktivitas zona hambat. Kata kunci: ekstrak ikan nike (Awaous melanocephalus); Fusobacterium nucleatum; daya hambat


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