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Effects of aqueous extract of Hibiscus sabdariffa on renal Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities in Wistar rats
Lawrence A. Olatunji
Zhong Xi Yi Jie He Xue Bao , 2012,
Abstract: OBJECTIVE: To investigate the effects of oral administration of aqueous extract of Hibiscus sabdariffa on renal Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities in rats.METHODS: The 25 and 50 mg/(kg·d) of aqueous extracts of H. sabdariffa were respectively given to rats in the experimental groups for 28 d, and rats in the control group received an appropriate volume of distilled water as vehicle. Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities in the kidney were assayed by spectrophotometric method.RESULTS: Administrations of 25 and 50 mg/(kg·d) of aqueous extract of H. sabdariffa significantly decreased the Ca2+-Mg2+-ATPase activity in the kidney of rats (P<0.05). However, the renal Na+-K+-ATPase activity of the experimental rats was not affected by either dose of the extract. And the plasma Na+, K+ and Ca2+ levels of the experimental rats had no significant changes. Administration of either dose of the extract did not result in any significant changes in body and kidney weights, the concentrations of plasma albumin and total protein, and alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. However, concentrations of creatinine and urea were significantly reduced by 50 mg/kg of the extract (P<0.05).CONCLUSION: The present study indicates that oral administration of aqueous extract of H. sabdariffa may preserve the renal function despite a decreased renal Ca2+-Mg2+-ATPase activity.
Focus: Drug Development: Alzheimer’s Toxic Amyloid Beta Oligomers: Unwelcome Visitors to the Na/K ATPase alpha3 Docking Station
David L. Brody,Erika N. Cline,Jeffrey Clark,Kirsten L. Viola,Madeline G. Rollins,Nadia DiNunno,Pauline T. Velasco,Riana Lo Bu,Stephen G. Sligar,Thomas DiChiara,William L. Klein,Yuesong Gong
- , 2017,
Abstract: Toxic amyloid beta oligomers (AβOs) are known to accumulate in Alzheimer’s disease (AD) and in animal models of AD. Their structure is heterogeneous, and they are found in both intracellular and extracellular milieu. When given to CNS cultures or injected ICV into non-human primates and other non-transgenic animals, AβOs have been found to cause impaired synaptic plasticity, loss of memory function, tau hyperphosphorylation and tangle formation, synapse elimination, oxidative and ER stress, inflammatory microglial activation, and selective nerve cell death. Memory loss and pathology in transgenic models are prevented by AβO antibodies, while Aducanumab, an antibody that targets AβOs as well as fibrillar Aβ, has provided cognitive benefit to humans in early clinical trials. AβOs have now been investigated in more than 3000 studies and are widely thought to be the major toxic form of Aβ. Although much has been learned about the downstream mechanisms of AβO action, a major gap concerns the earliest steps: How do AβOs initially interact with surface membranes to generate neuron-damaging transmembrane events? Findings from Ohnishi et al (PNAS 2005) combined with new results presented here are consistent with the hypothesis that AβOs act as neurotoxins because they attach to particular membrane protein docks containing Na/K ATPase-α3, where they inhibit ATPase activity and pathologically restructure dock composition and topology in a manner leading to excessive Ca++ build-up. Better understanding of the mechanism that makes attachment of AβOs to vulnerable neurons a neurotoxic phenomenon should open the door to therapeutics and diagnostics targeting the first step of a complex pathway that leads to neural damage and dementia
Renal effects of uroguanylin and guanylin in vivo
Carrithers, S.L.;Hill, M.J.;Johnson, B.R.;O'Hara, S.M.;Jackson, B.A.;Ott, C.E.;Lorenz, J.;Mann, E.A.;Giannella, R.A.;Forte, L.R.;Greenberg, R.N.;
Brazilian Journal of Medical and Biological Research , 1999, DOI: 10.1590/S0100-879X1999001100003
Abstract: uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase c; gc-c). these peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (na+, k+, cl-, hco3-) and fluid into the intestine via a cyclic guanosine-3',5'-monophosphate (cgmp) mechanism. gc-c is also the receptor for escherichia coli heat-stable enterotoxin (sta) and activation by sta results in a diarrheal illness. employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and sta elicit natriuretic, kaliuretic, and diuretic effects. these biological responses are time- and dose-dependent. maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. these data suggest the peptides act through tubular transport mechanisms. consistent with a tubular mechanism, messenger rna-differential display pcr of kidney rna extracted from vehicle- and uroguanylin-treated mice show the message for the na+/k+ atpase g-subunit is down-regulated. interestingly, gc-c knockout mice (gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through gc-c dependent and independent pathways. furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of ur
Renal effects of uroguanylin and guanylin in vivo
Carrithers S.L.,Hill M.J.,Johnson B.R.,O'Hara S.M.
Brazilian Journal of Medical and Biological Research , 1999,
Abstract: Uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase C; GC-C). These peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (Na+, K+, Cl-, HCO3-) and fluid into the intestine via a cyclic guanosine-3',5'-monophosphate (cGMP) mechanism. GC-C is also the receptor for Escherichia coli heat-stable enterotoxin (STa) and activation by STa results in a diarrheal illness. Employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and STa elicit natriuretic, kaliuretic, and diuretic effects. These biological responses are time- and dose-dependent. Maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. Our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. These data suggest the peptides act through tubular transport mechanisms. Consistent with a tubular mechanism, messenger RNA-differential display PCR of kidney RNA extracted from vehicle- and uroguanylin-treated mice show the message for the Na+/K+ ATPase g-subunit is down-regulated. Interestingly, GC-C knockout mice (Gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. Thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through GC-C dependent and independent pathways. Furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of urinary uroguanylin in patients with congestive heart failure. In conclusion, our studies support the concept that uroguanylin and guanylin are endogenous effector peptides involved in regulating body salt and water homeostasis.
Contemporary Dietary Intake: Too Much Sodium, Not Enough Potassium, yet Sufficient Iodine: The SALMEX Cohort Results
Angeles Espinosa-Cuevas,Angeles Mendoza-De la Garza,Bertha Herrero-Bervera,Iris Nieves-Anaya,Jorge I. Fonseca-Correa,Olynka Vega-Vega,Omar Dary,Ricardo Correa-Rotter,Rodolfo Rincón-Pedrero,Yolanda Baeza-Arias
- , 2018, DOI: 10.3390/nu10070816
Abstract: Initiatives to reduce sodium intake are encouraged globally, yet there is concern about compromised iodine intake supplied through salt. The aim of the present study was to determine baseline sodium, potassium, and iodine intake in a sample of workers from our Institution in Mexico City (SALMEX Cohort). Methods. From a cohort of 1009 workers, appropriate 24-h urine and three-day dietary recall was collected in a sample of 727 adult subjects for assessment of urinary sodium, potassium, and iodine concentrations. Median urinary iodine excretion (UIE) was compared across categories of sodium intake of <2, 2–3.6, and ≥3.6 g/day. Results. Average sodium intake was 3.49 ± 1.38 g/day; higher in men than women (4.14 vs. 3.11 g/day, p ≤0.001). Only 10.6% of the population had sodium intake within the recommended range (<2 g/day); 45.4% had high (2–3.6 g/day) and 44% had excessive intake (>3.6 g/day). Average urinary Na/K ratio was 3.15 ± 1.22 (ideal < 1), higher in men (3.42 vs. 3.0, p ≤ 0.001). The multivariate analysis showed that sodium intake was associated with age (p = 0.03), male sex (p < 0.001), caloric intake (p = 0.002), UKE (p < 0.001) and BMI (p < 0.001). Median iodine intake was 286.7 μg/day (IQR 215–370 μg/day). Less than 2% of subjects had iodine intake lower than recommended for adults (95 μg/day); 1.3% of subjects in the recommended range of salt intake had low iodine intake. There is a direct relationship between iodine and sodium urinary excretion (r = 0.57, p < 0.0001). Conclusions. In the studied population, there was an excessive sodium intake and an imbalance between sodium and potassium intake. Only 10.6% of the population had sodium intake within the recommended values, but iodine intake in this group appears to be adequate
Interaction between Single Nucleotide Polymorphism and Urinary Sodium, Potassium, and Sodium-Potassium Ratio on the Risk of Hypertension in Korean Adults
Chang Keun Kwock,Jihye Kim,Kyunga Kim,Yeong Mi Park,Yoon Jung Yang
- , 2017, DOI: 10.3390/nu9030235
Abstract: Hypertension is a complex disease explained with diverse factors including environmental factors and genetic factors. The objectives of this study were to determine the interaction effects between gene variants and 24 h estimated urinary sodium and potassium excretion and sodium-potassium excretion ratios on the risk of hypertension. A total of 8839 participants were included in the genome-wide association study (GWAS) to find genetic factors associated with hypertension. Tanaka and Kawasaki formulas were applied to estimate 24 h urinary sodium and potassium excretion. A total of 4414 participants were included in interaction analyses to identify the interaction effects of gene variants according to 24 h estimated urinary factors on the risk of hypertension. CSK rs1378942 and CSK-MIR4513 rs3784789 were significantly modified by urinary sodium-potassium excretion ratio. In addition, MKLN rs1643270 with urinary potassium excretion, LOC101929750 rs7554672 with urinary sodium and potassium excretion, and TENM4 rs10466739 with urinary sodium-potassium excretion ratio showed significant interaction effects. The present study results indicated that the mutant alleles of CSK rs1378942 and CSK-MIR4513 rs3784789 had the strongest protective effects against hypertension in the middle group of 24 h estimated urinary sodium-potassium excretion ratio. Further studies are needed to replicate these analyses in other populations
Phase and morphology evolution of (Na1-xKx)NbO3 powders related to calcinations and K2CO3 content
Pornsuda Bomlai,Winai Saengchote,Supasarote Muensit,Steven J. Milne
Songklanakarin Journal of Science and Technology , 2007,
Abstract: Sodium-potassium niobate ((Na1-xKx)NbO3) powders with x = 0.2, 0.4, 0.6 and 0.8 were prepared following the conventional mixed oxide method and characterized by TG-DTA, XRD and SEM techniques.The effects of calcination temperature, dwell time and K2CO3 content on phase formation behavior and morphology of the powders were investigated. The calcination temperature and dwell time were found tohave a pronounced effect on the phase formation of the calcined sodium-potassium niobate powders. It was found that the crystallized phase depended on calcination conditions. The high calcination temperature andlong dwell time clearly favored particle growth and the formation of large and hard agglomerates. All the (Na1-xKx)NbO3 powders showed a similar orthorhombic phase structure. The K2CO3 content significantlyaffected the calcination temperature and particle size and shape. Large particle size, cubic shape and a lower calcined condition were observed in (Na1-xKx)NbO3 powder with low K2CO3 content (x = 0.2).
Impact of Sodium Chloride and Heat on Survival Time of Linguatula Serrata Nymphs in vitro: An Experimental Study
B. Hajimohammadi,A. Akhondzadeh Basti,S. Shirali
Journal of Community Health Research , 2012,
Abstract: Introduction: Linguatula serrata is a zoonotic parasite, belonging to the class Pentastomida. The major aim of this study was to evaluate the impact of sodium chloride (NaCl) and heat on survival time of Linguatula serrata nymphs. Materials & Methods: Thirty nymphs (10 in triplicate) were separately transferred to plastic tubes, containing different concentrations of NaCl solution (2%, 5% and 10%). Meanwhile, 30 nymphs in tubes containing Phosphate Buffer Saline (PBS) were separately treated by +50°C, +60°C and +72°C. As control group, thirty nymphs were stored in PBS at +4°C. The effects of different conditions on survival time of the nymphs were evaluated by observing their motility in different periods of time. Results: The survival time of the nymphs stored in 10% NaCl solution was too short and all of them were dead after 3 hours. But the other ones maintained in 2% NaCl solution were significantly more resistant (p<0.05) and were survived for 2 days. All the nymphs pertaining to each +60°C and +72°C treatments were found dead after first 5-minute storage interval; the nymphs stored at +50°C died totally after 20 minutes. The nymphs maintained in PBS at +4°C (control group) showed the longest survival time (p<0.05); all of them were alive until day 4 and the last ones died on day 34. Conclusion: It is concluded that salting and heating have significant parasiticidal effects on L. serrata nymphs and could be used as disinfecting methods in processing of meat products especially liver. However, refrigeration at +4°C increases the resistance of the nymphs in meat products and therefore might endanger the food safety.
Prediction of Cortical Defect Using C-Reactive Protein and Urine Sodium to Potassium Ratio in Infants with Febrile Urinary Tract Infection
Jun Ho Lee,Su Jin Jung
- , 2016, DOI: 10.3349/ymj.2016.57.1.103
Abstract: We investigated whether C-reactive protein (CRP) levels, urine protein-creatinine ratio (uProt/Cr), and urine electrolytes can be useful for discriminating acute pyelonephritis (APN) from other febrile illnesses or the presence of a cortical defect on 99mTc dimercaptosuccinic acid (DMSA) scanning (true APN) from its absence in infants with febrile urinary tract infection (UTI)
Na+/HCO3- Cotransport in Normal and Cystic Fibrosis Intestine
Seidler U,Bachmann O,Jacob P,Christiani S
JOP Journal of the Pancreas , 2001,
Abstract: In a search for the HCO(3)(-) supply mechanisms to the enterocyte we cloned and sequenced an intestinal subtype of the Na(+)HCO(3)(-) cotransporter isoform I (dNBC1), which turned out to be identical to the pancreatic NBC1 subtype (pNBC1). Within the intestine, we found particularly high NBC1 expression levels in the duodenum and proximal colon. Experiments with stripped rabbit duodenum in Ussing-chambers revealed that Na(+)HCO(3)(-) cotransport (NBC) and CO(2) hydration/Na(+)/H(+) exchange were equally important duodenal HCO(3)(-) supply pathways and were both upregulated during cAMP-mediated secretion. In the proximal colon, however, HCO(3)(-) secretion was low but NBC1 expression even higher than in the duodenum. Ussing-chamber experiments with an NBC-specific inhibitor revealed that NBC, coupled to basolateral Cl(-)/HCO(3)(-) exchange, was an important alternative Cl(-) supply pathway to Na(+)K(+)2Cl(-) cotransport (NKCC) during cAMP-stimulated colonic Cl(-) secretion. To investigate the functional integrity of anion uptake pathways in the absence of cystic fibrosis transmembrane conductance regulator (CFTR), we fluorometrically assessed NBC and NKCC transport rates and cell volume before and during forskolin-stimulation in isolated colonic crypts from normal and CFTR (-/-) mice. Although forskolin stimulation decreased cell volume only in normal, not in CFTR (-/-) crypts, it activated NBC and NKCC to a similar degree in both normal and CFTR (-/-) crypts. We conclude that, depending on the intestinal segment, NBC1 plays an important role in basolateral HCO(3)(-) or Cl(-) uptake. Expression and activation by cAMP is preserved in CFTR (-/-) intestine.
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