Effect on renal function of essential fatty acid supplementation in cystic fibrosis

Strandvik, Birgitta; Berg, U; Kallner, Anders; Kusoffsky, E.

doi:10.1016/s0022-3476(89)80072-1

Cited by 47 publications

(35 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1). Such an interpretation of the results of this study is supported by the finding that the urinary sodium excretion was normalized after a sodium load in CF patients, who normalized their essential fatty acid pattern in serum phospholipids after long-term infusions of fat emulsions (23). Assuming that the findings in erythrocytes reflect a generalized membrane aberration related to a change of the composition of essential fatty acids, this might be secondary to an increased turnover (24,25).…”

Section: Discussionsupporting

confidence: 71%

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Sigström¹,

Strandvik²

1992

Pediatr Res

View full text Add to dashboard Cite

ABSTRACT. Ervthrocvtes from 15 vatients with cystic MATERIALS AND METHODSfibrosis (CF) aged 8 mb to 22 y (mean age 12.8 y) were analyzed for Na+,K+-ATPase activity and sodium, potassium, and ATP concentrations. Sodium concentrations and Na+-K+ ratio of erythrocytes were statistically significantly lower in the CF patients 16.6 (SD 1.9) versus 9.2 (SD 1.1) mmol/L (p < 0.01) and 0.070 (SD 0.023) versus 0.104 (SD 0.016) mmol/L (p < 0.01), respectively]. The Na+,K+-ATPase activity was similar compared with that of reference individuals 1536 (SD 100) versus 488 (SD 92) nmol inorganic phosphate/mg protein/h]. Intraerythrocyte sodium concentration and Na+-K+ ratio were thus lower in relation to the recorded Na+,K+-ATPase activities in controls, indicating a change of the passive transmembrane movements of sodium ions in CF. There was a rise of erythrocyte sodium and Na+-K+ ratio despite unchanged Na+,K+-ATPase activity after regular infusion of a fat emulsion rich in essential fatty acids, inferring that an altered membrane composition by essential fatty acid deficiency could explain the low intracellular sodium concentration in CF. (Pediatr Res 31: 425-427, 1992) Abbreviations CF, cystic fibrosis Na+,K+-ATPase, sodium-and potassium-activated adenosine triphosphatase Na+-K+ ratio, erythrocyte sodium-potassium ratio AA. arachidonic acidThe altered handling of sodium and chloride ions in sweat glands of patients with CF has proved to be related to a generalized phenomenon of impaired chloride conductance in epithelial cells (1-3). Furthermore, patients with CF have been shown to have an increased renal tubular reabsorption of sodium ions (4) not due to a depletion of sodium, inasmuch as the total exchangeable sodium was normal (5). Active sodium-potassium transport is the main activity exerting proximal tubular sodium reabsorption and is also working in erythrocytes (6). It was therefore indicated to study the enzymatic activity responsible for this transport and the results thereof, namely the Naf,K+-ATPase and the intracellular concentrations of sodium and potassium (7,8). By measuring these parameters in erythrocytes, evidence of a generalized different handling of sodium ions could be obtained. Patients. Fifteen patients (eight males and seven females) were studied. The mean age was 12.8 y and the ages varied between 8 mo and 22 y. All patients had sweat chloride concentrations above 60 mmol/L. All patients had pancreatic insufficiency and pulmonary symptoms. The clinical condition was considered good in seven cases [Schwachman score >70 (9)], moderate in five cases (Schwachman score 50-70), and severe in three cases (Schwachman score (50).All patients had a standard diet without restrictions. Three of the patients had an extra supply of glucose polymer formulas. All patients had supplementations of pancreatic enzymes and fat soluble vitamins. Four of the patients received regular infusions of a 10% fat emulsion (Intralipid, Kabi Pharmacia, Sweden) during 3 consecutive d every 4 to 6 wk (2 g/kg body wt/8 h). All pati...

show abstract

Section: Discussionsupporting

confidence: 71%

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Sigström¹,

Strandvik²

1992

Pediatr Res

View full text Add to dashboard Cite

show abstract

“…[28], may be responsible for the decreased ability of CF patients to excrete an NaCl load [34]. The results of the present study suggest that the CFTR protein may regulate and/or participate with other C1 pathways in the electrogenic CI secretion in IMCD.…”

mentioning

confidence: 64%

Properties of a Cl⁻‐Conductive Pathway(s) in Microsomes from Rat Kidney Inner Medulla

Benharouoa

Lipecka

Fanen

et al. 1996

European Journal of Biochemistry

View full text Add to dashboard Cite

The properties of a protein-kinase-A(PKA)-activated Cl--conductive pathway( s) in alkaline phosphatase-enriched microsomes from the rat inner medulla (IMV) were investigated. Transcripts of cystic fibrosis transmembrane regulator (CFTR) were detected by reverse transcription/polymerase analysis of total RNA from the inner medulla, while immunoblot analysis using anti-CFTR antibodies detected a 170-kDa protein in the IMV. The PKA C1--conductive pathway(s) was studied by measuring the rate of valinomycin-induced microsomal swelling by light scattering. PKA increased the rate of valinomycin-induced swelling of vesicles consistent with the presence of C1--conductive pathway(s). The pharmacological properties and anion selectivity of the PKA-activated Cl--conductive pathway(s) were similar to those of the CFTR CI-channel. Our results show that a CFTR C1 channel and possibly another CAMP-activated pathway(s) may participate in Cl-secretion in the rat inner medulla.Keywords: kidney; inner medulla; cystic fibrosis transmembrane regulator; chloride conductance; chloride channel.The main function of the tubules in the kidney inner medulla, which are mostly collecting ducts (IMCD), is to modify the composition of urine before it leaves the kidney [l], and thus control the concentration of renal excretion. Most functional investigations of IMCD have focused on sodium absorption [2, 31, but recent studies suggest that chloride secretion may also contribute to the regulation of final urine composition and volume [4]. Studies on isolated perfused IMCD from the rat have also shown that CAMP stimulates C1-se.cretion [4-61. It has been suggested that the cystic fibrosis transmembrane regulator (CFTR) chloride channel mediates the electrogenic chloride secretion in mouse IMCD-K2 cells 171 and rat primary cultures of IMCD cells [8]. This is supported by the presence of transcripts for CFTR protein along the nephron [9], and a protein immunologically related to CFTR in the proximal and distal tubules of the human kidney [lo]. To add to the evidence for the presence of a functional CFTR in the IMCD, we performed the present study on microsomes from rat inner medulla (IMV). The goal was to determine whether the CAMP-activated CI-. fluxes in IMV have pharmacological features and anion selectivity similar to those of the CFTR Cl-channel.Reverse transcription, (RT)-PCR, and western blot analysis indicated that CFTR protein is expressed in the inner medulla of the rat kidney. The functional assay based on valinomycininduced vesicle swelling provided evidence that protein-kinase-A (PKA) regulated CI--conductive pathways are present in the inner medulla vesicles (IMV) and that a protein with the pharniacological properties of the CFTR-C1-channel is involved in the regulation of one of these pathways. MATERIALS AND METHODSMaterials. ATP, PKA, valinomycin, phenylmethylsulfonyl fluoride (PhMeSO,F), leupeptin, pepstatin A, Hepes, Tris, 4 acetamido-4'-isothiocyanato-stilbene-2,2'-disulfonic acid, BSA fraction V, and Ponceau S were obtained froin...

show abstract

“…1 except for (40) or by direct secretion of parent compound from intestinal mucosa (52). The renal elimination of many antibiotics is enhanced in CF subjects, usually in relation to the increased GFR (21,22 (47). Furthermore, the renal tubular function in CF patients may be altered, as evidenced by disturbances in renal sodium handling (7,46).…”

Section: Resultsmentioning

confidence: 99%

Increased oral bioavailability of ciprofloxacin in cystic fibrosis patients

Christensson

Nilsson-Ehle

Ljungberg

et al. 1992

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The altered pharmacokinetic properties of, e.g., aminoglycosides in cystic fibrosis patients have to be considered when pulmonary exacerbations are treated. Since reported data on ciprofloxacin, a fluorinated quinolone, are conflicting, we compared intravenous and oral administration in cystic fibrosis patients when treating them for mild symptoms of pulmonary infection. All of the patients were colonized with Pseudomonas species. Ciprofloxacin was administered orally (15 mg/kg of body weight) or intravenously (6 mg/kg) twice a day for at least 10 days during separate treatment periods. Five healthy volunteers received single intravenous and oral doses. Pharmacokinetic evaluations were performed at first dose and at steady state. The results showed that cystic fibrosis patients have increased oral bioavailability of ciprofloxacin (80% in cystic fibrosis patients versus 57% in volunteers) and increased total clearance (688 ml/min in CF patients versus 528 ml/min in volunteers). Our data indicate that the pharmacokinetic properties of ciprofloxacin are altered in cystic fibrosis patients with mild symptoms of pulmonary exacerbations and that the changes most probably are due to cystic fibrosis per se or to the impact of chronic infection.

show abstract

Effect on renal function of essential fatty acid supplementation in cystic fibrosis

Cited by 47 publications

References 42 publications

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Properties of a Cl⁻‐Conductive Pathway(s) in Microsomes from Rat Kidney Inner Medulla

Increased oral bioavailability of ciprofloxacin in cystic fibrosis patients

Contact Info

Product

Resources

About

Effect on renal function of essential fatty acid supplementation in cystic fibrosis

Cited by 47 publications

References 42 publications

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Erythrocyte Sodium-Potassium Transport in Cystic Fibrosis

Properties of a Cl−‐Conductive Pathway(s) in Microsomes from Rat Kidney Inner Medulla

Increased oral bioavailability of ciprofloxacin in cystic fibrosis patients

Contact Info

Product

Resources

About

Properties of a Cl⁻‐Conductive Pathway(s) in Microsomes from Rat Kidney Inner Medulla