Arginine vasopressin regulates the renal Na+-Cl- and Na+-K+-Cl- cotransporters through with-no-lysine kinase 4 and inhibitor 1 phosphorylation.

Vasopressin regulates water homeostasis via the V2 receptor in the kidney at least in part through protein kinase A (PKA) activation. Vasopressin, through an unknown pathway, upregulates the activity and phosphorylation of Na+-Cl- cotransporter (NCC) and Na+-K+-2Cl- cotransporter 2 (NKCC2) by Ste20-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase 1 (OSR1), which are regulated by the with-no-lysine kinase (WNK) family. Phosphorylation of WNK4 at PKA consensus motifs may be involved. Inhibitor 1 (I1), a protein phosphatase 1 (PP1) inhibitor, may also play a role. In human embryonic kidney (HEK)-293 cells, we assessed the phosphorylation of WNK4, SPAK, NCC, or NKCC2 in response to forskolin or desmopressin. WNK4 and cotransporter phosphorylation were studied in desmopressin-infused WNK4-/- mice and in tubule suspensions. In HEK-293 cells, only wild-type WNK4 but not WNK1, WNK3, or a WNK4 mutant lacking PKA phosphorylation motifs could upregulate SPAK or cotransporter phosphorylation in response to forskolin or desmopressin. I1 transfection maximized SPAK phosphorylation in response to forskolin in the presence of WNK4 but not of mutant WNK4 lacking PP1 regulation. We observed direct PP1 regulation of NKCC2 dephosphorylation but not of NCC or SPAK in the absence of WNK4. WNK4-/- mice with desmopressin treatment did not increase SPAK/OSR1, NCC, or NKCC2 phosphorylation. In stimulated tubule suspensions from WNK4-/- mice, upregulation of pNKCC2 was reduced, whereas upregulation of SPAK phosphorylation was absent. These findings suggest that WNK4 is a central node in which kinase and phosphatase signaling converge to connect cAMP signaling to the SPAK/OSR1-NCC/NKCC2 pathway.NEW & NOTEWORTHY With-no-lysine kinases regulate the phosphorylation and activity of the Na+-Cl- and Na+-K+-2Cl- cotransporters. This pathway is modulated by arginine vasopressin (AVP). However, the link between AVP and WNK signaling remains unknown. Here, we show that AVP activates WNK4 through increased phosphorylation at putative protein kinase A-regulated sites and decreases its dephosphorylation by protein phosphatase 1. This work increases our understanding of the signaling pathways mediating AVP actions in the kidney.

Identificação de agentes e resposta aos tratamentos na cistite neurogênica em cães com lesão na coluna tóraco-lombar / Identification of agents and response to the treatments in the neurogenic cystitis in dogs with injury in the thoracolumbar column

Lesões agudas na coluna tóraco-lombar podem provocar inibição da micção, retenção e estase urinária. A antibioticoterapia fica indicada baseada na urocultura e antibiograma. Em alguns casos a antibioticoterapia é ineficaz, e os pacientes demonstram piora no quadro clínico. Este trabalho tem por objetivo identificar bactérias presentes na urina de cães com lesão da coluna tóraco-lombar, retenção urinária e paresia dos membros pélvicos. Foran utilizados 11 cães, divididos em dois grupos: seis no GI (≤ 7 dias de sintomatologia) e cinco no GII (≥ 30 dias de sintomatologia). Realizou-se urocultura e antibiograma, na qual foram atestados ampicilina, amoxilina, cefalexina, cefalotina, cefalozina, ciproflaxina, estreptomicina, florfenicol, gentamicina, neomicina, norfloxacina, penicilina G, tetraciclina e sulfadiazina/trimetropim. A escolha do antibiótico baseou-se resultado do antibiograma, pH urinário e pela comparação da CUM com a CIM. Em nove cães houve crescimento bacteriano: Staphylococcus spp (30%), Sreptococcus spp (20%) e Echerichia coli (30%) em GI e GII, e Corynebacterium SP (10%) no GII. No GI utilizou-se no tratamento enrofloxacina, cefalotina ou sulfadiazina com trimetropim, sendo que todos os cães apresentaram urocultura negativa após 14 dias. No GII foram utilizados sulfadiazina com trimetropim, cefazolina, florfenicol ou norfloxacina. Apenas o cão tratado com cefazolina continuava com urocultura positiva, visto que o pH urinário de atuação do antimicrobiano não estava adequado. Conclui-se, então, que para escolher o antibiótico é necessário saber a sensibilidade antimicrobiana, o pH urinário e a concentração urinária média (pelo menos quatro vezes maior que a CIM)

The acute injuries in the thoracolumbar column can provoke inhibition of the miction, urinary retention and stasis. The antibiotic therapy, if will not be based on the uruculture and in the test of antimicrobial sensitivy. In the clinical state. This paper has for objective to isolate bacteria gifts in urine of dogs with injury of the thoracolumbar column, urinary retention and paresis of behind limbs. There were used 11 dogs, divided in two groups: six in GI (≤7 days of sintomatology) and five in GII (≥30 days of sistomatology). Before, there was done the uruculture and the antimicrobial sensibility test with: ampicilin, cephalexin, cephalothin, cephazolin, ciprofloxacin, enrofloxacin, streptomycin, flofernicol, gentamicin, neomycin, norfloxacin, penicillin G, tetracycline e sulphadiazine/trimethropim. The change of the antibiotic was of the antimicrobial sensibility test result, urinary pH and comparision of the MUC with the MIC. In nine dogs there was bacterial groeth: Staphylococcus spp (30%), Streptococcus spp (20%) and Eschreichia coli (30%) in GI and GII, and Corynebacterium sp (10%) and Pseudomonas sp (10%) in the GII. In GI were used enrofloxacin, cephalothin or sulphadiazine, and all dogs had negative uruculture, after 14 days of treayment. In GII was used sulphadiazine/trimetroprime, cephazolin, florfenicol or norfloxacin. Only the dog treatment with cephazolin continued with uruculture positive, as the urinary pH that the antibiotical action not was adequated. It is concluded then that to choose the antibiotic it is necessary to know antimicrobial sensitivy, urinary pH and medium concentration (at least four times bigger that the CIM)

Identificação de agentes e resposta aos tratamentos na cistite neurogênica em cães com lesão na coluna tóraco-lombar / Identification of agents and response to the treatments in the neurogenic cystitis in dogs with injury in the thoracolumbar column

Lesões agudas na coluna tóraco-lombar podem provocar inibição da micção, retenção e estase urinária. A antibioticoterapia fica indicada baseada na urocultura e antibiograma. Em alguns casos a antibioticoterapia é ineficaz, e os pacientes demonstram piora no quadro clínico. Este trabalho tem por objetivo identificar bactérias presentes na urina de cães com lesão da coluna tóraco-lombar, retenção urinária e paresia dos membros pélvicos. Foran utilizados 11 cães, divididos em dois grupos: seis no GI (≤ 7 dias de sintomatologia) e cinco no GII (≥ 30 dias de sintomatologia). Realizou-se urocultura e antibiograma, na qual foram atestados ampicilina, amoxilina, cefalexina, cefalotina, cefalozina, ciproflaxina, estreptomicina, florfenicol, gentamicina, neomicina, norfloxacina, penicilina G, tetraciclina e sulfadiazina/trimetropim. A escolha do antibiótico baseou-se resultado do antibiograma, pH urinário e pela comparação da CUM com a CIM. Em nove cães houve crescimento bacteriano: Staphylococcus spp (30%), Sreptococcus spp (20%) e Echerichia coli (30%) em GI e GII, e Corynebacterium SP (10%) no GII. No GI utilizou-se no tratamento enrofloxacina, cefalotina ou sulfadiazina com trimetropim, sendo que todos os cães apresentaram urocultura negativa após 14 dias. No GII foram utilizados sulfadiazina com trimetropim, cefazolina, florfenicol ou norfloxacina. Apenas o cão tratado com cefazolina continuava com urocultura positiva, visto que o pH urinário de atuação do antimicrobiano não estava adequado. Conclui-se, então, que para escolher o antibiótico é necessário saber a sensibilidade antimicrobiana, o pH urinário e a concentração urinária média (pelo menos quatro vezes maior que a CIM)(AU)

The acute injuries in the thoracolumbar column can provoke inhibition of the miction, urinary retention and stasis. The antibiotic therapy, if will not be based on the uruculture and in the test of antimicrobial sensitivy. In the clinical state. This paper has for objective to isolate bacteria gifts in urine of dogs with injury of the thoracolumbar column, urinary retention and paresis of behind limbs. There were used 11 dogs, divided in two groups: six in GI (≤7 days of sintomatology) and five in GII (≥30 days of sistomatology). Before, there was done the uruculture and the antimicrobial sensibility test with: ampicilin, cephalexin, cephalothin, cephazolin, ciprofloxacin, enrofloxacin, streptomycin, flofernicol, gentamicin, neomycin, norfloxacin, penicillin G, tetracycline e sulphadiazine/trimethropim. The change of the antibiotic was of the antimicrobial sensibility test result, urinary pH and comparision of the MUC with the MIC. In nine dogs there was bacterial groeth: Staphylococcus spp (30%), Streptococcus spp (20%) and Eschreichia coli (30%) in GI and GII, and Corynebacterium sp (10%) and Pseudomonas sp (10%) in the GII. In GI were used enrofloxacin, cephalothin or sulphadiazine, and all dogs had negative uruculture, after 14 days of treayment. In GII was used sulphadiazine/trimetroprime, cephazolin, florfenicol or norfloxacin. Only the dog treatment with cephazolin continued with uruculture positive, as the urinary pH that the antibiotical action not was adequated. It is concluded then that to choose the antibiotic it is necessary to know antimicrobial sensitivy, urinary pH and medium concentration (at least four times bigger that the CIM)(AU)