Buffy Coat and Serum Concentration of Potassium Related to the Acid-base Status in Dogs Following Induced Hypokalemia
| العنوان: | Buffy Coat and Serum Concentration of Potassium Related to the Acid-base Status in Dogs Following Induced Hypokalemia |
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| المؤلفون: | C. Vásquez-Peláez, Jan Bouda, J. Aguilar-Bobadilla, L. Núnez-Ochoa |
| المصدر: | Acta Veterinaria Brno, Vol 74, Iss 2, Pp 225-232 (2005) |
| بيانات النشر: | University of Veterinary and Pharmaceutical Sciences, Brno, 2005. |
| سنة النشر: | 2005 |
| مصطلحات موضوعية: | medicine.medical_specialty, Alkalosis, lcsh:Veterinary medicine, General Veterinary, Hyperkalemia, Chemistry, Metabolic alkalosis, Furosemide, Buffy coat, medicine.disease, Hypokalemia, Endocrinology, Blood serum, Internal medicine, medicine, lcsh:SF600-1100, Na+/K+-ATPase, medicine.symptom, medicine.drug |
| الوصف: | Aguilar-Bobadi l la J . , J . Bouda, L. Nunez-Ochoa, C. Vasquez-Pelaez: Buffy Coat and Serum Concentration of Potassium Related to the Acid-base Status in Dogs Following Induced Hypokalemia. Acta Vet Brno, 2005, 74: 225-232. Electrolyte and acid-base disturbances are frequent in sick dogs. The objective of this study was to determine the concentration of K+ in blood serum and buffy coat K+ (BC K+) and its relation to other serum electrolytes and acid-base values in blood of healthy dogs and those with hypokalemia induced by furosemide. The study was performed on 42 dogs of both sexes, aged 3 to 8 years, divided into two groups. Group 1 (control, n = 21) included healthy dogs, Group 2 (experimental, n = 21) consisted of healthy dogs in which hypokalemia had been induced using furosemide at a dose of 12 mg/kg PO BID during 21 days. Physical examination, haemogram (16 analytes), biochemical profile (22 analytes) and urinalysis (15 analytes) were performed to evaluate the health status of all dogs. In this study, the most important serum analytes were Na+, K+ and Cl-; BC K+ and blood pH, HCO3 -, base excess (BE), as well as pCO2. A method for obtaining BC and determining intracellular K+ was developed. Between groups 1 and 2, serum K+ had a significant correlation with pH, HCO3 and BE (r > 0.6, p 0.7, p 0.7, p < 0.01), suggesting SID as a good indicator of K+ translocation in metabolic alkalosis. The anion gap (AG) did not present significant correlation with BC K+, with serum Na+, K+ and Cl-, or with pH, HCO3 -, BE and pCO2. For the evaluation of electrolyte alterations and metabolic acid-base disorders it is necessary to include in laboratory profiles the determination of K+, Na+, Cl-, HCO3 in blood serum, as well as to calculate AG, SID, and relate them to the physical examination of the animal. Dog, furosemide, buffy coat potassium, serum electrolyte, acid-base status Acid-base and electrolyte disturbances are frequently present in sick dogs. Approximately 95% of the total potassium (K+) is intracellular, of which 60 to 75% is contained in the muscles, thus causing it to be the main ion at this level (MacInt i re 1997; Phi l l ips and Polzin 1998). K+ maintains intracellular volume and a normal membrane potential (Bi lbrey et al. 1973; Field et al. 1987). In healthy animals, daily intake of K+ equals the losses. In extracellular fluid (ECF) the average sodium (Na+) concentration is 150 mmol/L and that of K+ is 4 mmol/L. In dogs, the Na+:K+ proportion in intracellular fluid (ICF) is inverted. Experimental studies in healthy dogs have muscle tissue Na+ and K+ levels ranging from 8.4 to 13.7 mmol/L and 139 to 142 mmol/L, respectively (Phi l l ips and Polzin 1998). One study, in dogs, determined total K+ concentration to be 47.1 mmol/kg of body weight, ranging from 39.8 to 61.1 mmol/kg (Di Bartola and De Morais 2000). The normal proportion of extracellular and intracellular potassium is maintained by the sodiumACTA VET. BRNO 2005, 74: 225–232 Address for correspondence: Prof. MVDr. J. Bouda, DrSc. Departamento de Patologia Facultad de Medicina Veterinaria Universidad Nacional Autonoma de Mexico, Ciudad Universitaria Av. Universidad 3000, Col. Copilco, Mexico, D.F. 04510 Phone and Fax: (01 55) 56 22 58 78 E-mail: bouda@servidor.unam.mx http://www.vfu.cz/acta-vet/actavet.htm potassium pump found in cell membranes. This pumps Na+ ions out and K+ ions into the cell at a 3:2 ratio (Di Bartola and De Morais 2000; Hendrix and Raffe 1994). The ability of specialized cells to develop a membrane potential is crucial for normal cardiac conduction, muscular contraction and the transmission of nervous impulses (Di Bartola and De Morais 2000; Kornegay 1995). K+ homeostasis in the organism is maintained through dietary intake and excretion in urine (Di Bartola and De Morais 2000). Changes in pH can produce K+ translocation between ICF and ECF. In general, acidosis is associated with the movement of K+ from ICF to ECF, while during alkalosis K+ ions move in the opposite direction (I lkiw et al. 1989; Schaer 1993; Di Bartola and De Morais 1993; Di Bartola et al. 1994). Hypokalemia is one of the most frequently encountered electrolyte disturbances in critical patients. It presents when there is a lack of nutrients, such as in anorexia, or when there are excessive losses during vomiting (Bel lenger et al. 1990). Polyuria also causes hypokalemia, be it from chronic renal failure or any type of polyuric diuresis, such as: release of a urinary tract obstruction, nephrogenic diabetes insipidus (Phi l l ips and Polzin 1998; Di Bartola and De Morais 2000); prostatic abscesses or pyometra, both of which cause E. coli toxin deposition in renal tubules with subsequent interference on Na+ and Clabsorption; medullary washout; and the use of loop diuretics (Di Bartola and De Morais 2000). Finally, hypokalemia is also seen with translocation of potassium into ICF during respiratory or metabolic alkalosis (MacInt i re 1997). In animals with diabetic ketoacidosis, the level of K+ in serum can drop after insulin treatment, since this favors the entrance of potassium into the ICF. Correcting the acidotic state also reverts the translocation; thus the importance of monitoring serum K+ in diabetic patients (Schaer 1993a). Hypokalemia, induced by K+ translocation to ICF, is observed in dogs with hyperventilatory respiratory alkalosis (Muir et al. 1990). Both in hypoand hyperkalemia, the proportion of intracellular (IC) and extracellular (EC) K+ is altered, and the membrane potentials in excitable heart tissue, nerves and muscles are affected, producing altered conduction rates (MacIntire 1997). The reference range for kalemia in dogs is from 3.92 to 5.54 mmol/L, thus defining hypokalemia as values lower than those referred and hyperkalemia as values higher than reference values (Kirk 1980; Nunez 2001). The only practical measurement of the change of body K+ is the concentration of K+ in serum; representing only 5% of the total given that 95% is found in the IC level (Phi l l ips and Polzin 1998). With this in mind, the aim of the present study was to determine the relationship between K+ in the buffy coat (BC) with that observed in serum, as well as of both of these with the acid-base evaluation in healthy dogs and those in which hypokalemia had been induced. Materials and Methods Forty-two clinically healthy dogs of both sexes, aged three to eight years, were divided into two groups. Group 1 (control) consisted of 21 healthy dogs, ten German shepherds (seven males and three females) and 11 mixedbreed dogs (three females and eight males). Physical examination, haemogram (16 analytes), biochemical profile (22 analytes) and urinalysis (15 analytes) were performed to evaluate the health status of all dogs. None of them showed any alterations in the haematological indices, serum biochemistry or urinalysis (Lees et al. 1994; Nunez 2001). Group 2 (experimental) was made up of 21 mixed-breed dogs (nine females and 12 males) in which hypokalemia (< 3.8 mmol/L) had been induced using furosemide at a dosage rate of 12 mg/kg PO BID during 21 days (Bonagura et al. 2000; Senior 1995). Blood samples were obtained from either the jugular or cephalic vein, after an eight-hour fast. The urine samples were collected via catheterization or cystocentesis. Procedures were developed to obtain the buffy coat (BC) and determine intracellular K+. Venous blood samples were collected in vacuum tubes (Vacutainer) containing sodium heparin. Blood components were separated using a relative centrifugal force (RCF) of 1200 g during 10 min, thus obtaining red blood cells, buffy coat and plasma. The plasma was decanted and approximately one mL of BC containing red blood cells was removed to fill a Wintrobe tube. A second centrifugation at 1200 g for 10 min was carried out, this separated the components leaving the red blood cells on the bottom and the buffy coat on the 226 |
| اللغة: | English |
| تدمد: | 1801-7576 0001-7213 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d2fd6aad20b1048bc8603d6b2908cf79 https://actavet.vfu.cz/74/2/0225/ |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....d2fd6aad20b1048bc8603d6b2908cf79 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 18017576 00017213 |
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