Diuretic Action of Apelin-13 Mediated by Inhibiting cAMP/PKA/sPRR Pathway

Emerging evidence is showing that apelin plays an important role in regulating salt and water balance by counteracting the antidiuretic action of vasopressin (AVP). However, the underlying mechanism remains unknown. Here, we hypothesized that (pro) renin receptor (PRR)/soluble prorenin receptor (sPRR) might mediate the diuretic action of apelin in the distal nephron. During water deprivation (WD), the urine concentrating capability was impaired by an apelin peptide, apelin-13, accompanied by the suppression of the protein expression of aquaporin 2 (AQP2), NKCC2, PRR/sPRR, renin and nuclear β-catenin levels in the kidney. The upregulated expression of AQP2 or PRR/sPRR both induced by AVP and 8-Br-cAMP was blocked by apelin-13, PKA inhibitor (H89), or β-catenin inhibitor (ICG001). Interestingly, the blockage of apelin-13 on AVP-induced AQP2 protein expression was reversed by exogenous sPRR. Together, the present study has defined the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/sPRR pathway in the CD as the molecular target of the diuretic action of apelin.

Comparison of pharmacological activity of hawthorn fruits preparations

Objectives - a comparative study of antidepressant activity and diuretic action of water and water-alcohol preparations of the fruits of Crataegus sanguinea Pall. and Crataegus submollis Sarg. Materials and methods. The study covers the water and alcohol-water extracts from the fruits of hawthorn blood-red (Crataegus sanguinea Pall.) and Quebec hawthorn (Crataegus submollis Sarg.). The comparative study of the antidepressant activity and the diuretic action of the preparations was carried out on white mongrel rats of both sexes. Results. The liquid extracts of fruits Crataegus sanguinea Pall. and Crataegus submollis Sarg. at a dose of 100 μl/kg revealed an antidepressant activity. Decoctions of Crataegus sanguinea Pall. and Crataegus submollis Sarg. at a dose of 100 μl/kg had a pronounced diuretic and saluretic activity. Pharmacotherapeutic effects of the studied preparations can be explained by the presence of flavonoids in them. Conclusion. The preparations of the fruits of Crataegus sanguinea Pall. and Crataegus submollis Sarg. can be recommended as antidepressant and diuretic agents. The fruits of Crataegus submollis Sarg. are the promising medicinal plant raw materials.

ORAL DIURETIC ACTIVITY OF HOT WATER EXTRACT OF H-GRADE QUILLS OF CINNAMOMUM ZEYLANICUM BLUME IN RATS

Objective: Cinnamomum zeylanicum Blume is claimed in Sri Lankan traditional medicine as a diuretic. Diuretics that are in current use possess serious adverse effects. Thus, there is a need for discovering efficacious and safe diuretics possibly from natural sources. Hence, the study was carried out to scientifically evaluate the diuretic potential of Cinnamomum zeylanicum Blume in vivo.Methods: Wistar albino rats weighing 180-270 g of either sex were divided into five groups containing six subjects in each. All were starved for 18 h and hydrated subsequently with oral sodium chloride solution (0.9%). Group, I (control) received normal saline (15 ml per animal orally). Group II, III, and IV received different doses (1500, 2250, 3000 mg/kg) of freeze-dried hot water extract of Cinnamomum zeylanicum Blume orally. Group V; (standard) received furosemide (13 mg/kg). Rats were placed individually in metabolic cages. Cumulative urine outputs at hourly intervals for six hours, urinary Na+, K+, Cl-, HCO3-, specific gravity, pH and total dissolved solids were determined. Results: A strong dose-dependent diuretic activity with a rapid onset of action, rapid peak diuresis and short duration of action was observed compared to furosemide. The diuretic action was accompanied with a significant (p<0.05) increase in urinary Na+, HCO3- and pH and decrease in urinary H+. Conclusion: The results indicated that hot water extract of Cinnamomum zeylanicum Blume possesses marked diuretic action compared to furosemide. This is mediated primarily via loop diuretic mechanism similar to furosemide and partly by carbonic anhydrase inhibitory action.

Effect of Sesbania grandiflora Linn leaf extracts on diuresis in wistar rats

Background: This study was designed to evaluate the effect of sesbania grandiflora linn leaf extracts on diuretic activity in wistar rats.Methods: Healthy male wistar albino rats divided into 9 groups and weighing 150-200gm.diuretic activity was expressed by Natriuretic activity, saluretic activity, carbonic anhydrase inhibition, Diuretic index or Diuretic action, saluretic index, Natriuretic index. Animalgroups are divided into: group1 treated as control, 2and 3 treated as standards, group 4, 5 and 6 treated with aqueous leaf extract of Sesbania grandiflora Linn. in different doses of 150,300,450mg/kg. Group 7,8and 9 treated with methanolic leaf extract of Sesbania grandiflora Linn. Doses of 150,300,450mg/kg.Results: No change in body weight group treated with AE-150 (p>0.05) with AE-150 (0.1%), increase in urine volume with increasing doses both with aqueous and methanolic extracts, sodium excretion with methanolic extract was high compared with the aqueous extract, significant increase in potassium excretion in both aqueous and methanolic extract treated groups.All the statistical tests were done by using SPSS version 6. The level of significance was 5% (p≤0.05).Conclusions: All the electrolytes concentration was increased in the urine, hence excluding osmotic diuretic action. Diuretic index, saluretic activity, saluretic index and natriuretic index of ME-450 were more than the value of hydrochlorothiazide hence excludes thiazide diuretic action. But these values were less than furosemide.