The relationship between S system of blood groups and potassium levels in red blood cells of cattle

Comparative study on 3 oral potassium formulations for treatment of hypokalemia in dairy cows

BACKGROUND

Hypokalemia is of clinical relevance in cattle. Different mostly empirical treatment options are suggested.

HYPOTHESIS/OBJECTIVES

To evaluate if oral administration of potassium influences the plasma concentration, the intracellular concentration in erythrocytes and in muscle, renal excretion of potassium, and to assess if there are differences in the efficacy of the potassium formulations.

ANIMALS

Thirty cows with hypokalemia (plasma concentration <3.5 mmol/L) were systematically allocated to 3 treatment groups (10 cows/group).

METHODS

The cows received 52 g of potassium in different formulations: group B-potassium chloride bolus (release over 12 hours); group G-potassium propionate gel (release over 2 hours); and group S-potassium chloride solution (immediately available). Potassium concentrations were repeatedly measured in plasma, erythrocytes, muscle, and urine using ICP-OES.

RESULTS

Plasma potassium concentrations for all preparations increased within 30 minutes and the increase lasted for 12 hours. The concentrations of potassium in the erythrocytes and in the muscle, renal potassium excretion, and total urine volume were not affected by administration of any product. There were no differences between the treatments groups. The feed intake increased in 50% of cows within 2 hours after potassium application, which may contribute to the increase of plasma potassium concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

All the studied potassium formulations are equally effective to treat hypokalemia in dairy cows for over 12 hours but do not influence intracellular concentration or renal excretion of potassium. The plasma potassium concentration should be reevaluated after 12 hours.

Concentration of Potassium in Plasma, Erythrocytes, and Muscle Tissue in Cows with Decreased Feed Intake and Gastrointestinal Ileus

BACKGROUND

Healthy cows consume large amounts of potassium and a sudden loss in appetite can lead to hypokalemia. The routine method to evaluate potassium homeostasis is the measurement of the extracellular potassium in plasma or serum, but this does not provide information about the intracellular potassium pool.

HYPOTHESIS/OBJECTIVES

To evaluate potassium homeostasis by comparing the extracellular and intracellular potassium concentration in cows with reduced feed intake and gastrointestinal ileus.

ANIMALS

Twenty cows 1-3 days postpartum (group 1) and 20 cows with gastrointestinal ileus (group 2).

METHODS

Observational cross-sectional study. Plasma potassium was measured by using an ion-sensitive electrode. Intracellular potassium was measured in erythrocytes and muscle tissue (muscle biopsy) by using inductively coupled plasma optical emission spectroscopy.

RESULTS

Cows of group 1 did not have hypokalemia. Overall cows with gastrointestinal ileus were hypokalemic (mean ± SD, 2.9 mmol/L ± 0.78), but potassium concentration in erythrocytes and muscle tissue was not lower than in postpartum cows. Intracellular potassium in erythrocytes varied very widely; group 1: 3497-10735 mg/kg (5559 ± 2002 mg/kg), group 2: 4139-21678 mg/kg (7473 ± 4034 mg/kg). Potassium in muscle tissue did not differ between group 1 (3356 ± 735 mg/kg wet weight) and group 2 (3407 ± 1069 mg/kg wet weight). No association between extracellular and intracellular potassium concentrations was detected.

CONCLUSIONS AND CLINICAL IMPORTANCE

That measurement of plasma potassium concentration is not sufficient to evaluate potassium metabolism of cows.

Comparative aspects of biochemical polymorphism in the blood of Caprinae species and their hybrids

Biochemical variation at 14 blood loci was reviewed, and specific features compared experimentally in sheep Ovis aries, mouflon Ovis musimon, goat Capra hircus, aoudad Ammotragus Iervia and in 2 stillborn aoudad X goat hybrids. Variation at 3 loci was also studied in dall sheep Ovis dalli, bighorn sheep Ovis canadensis and rocky mountain goat Oreamnos americanus. Haemoglobin C production in an anaemic Hb AB mouflon and in mouflon X sheep hybrids was examined. Mouflon differ from domestic sheep in that synthesis of both Hb beta A and Hb beta B chains is switched off during Hb C production. The mouflon X sheep hybrids switched off one or both chains depending on whether they had inherited sheep or mouflon Hb beta chain genes. In general aoudad showed a closer affinity to goats than to sheep.

The distribution of potassium and sodium concentrations in the erythrocytes of some breeds of cattle

SUMMARY

The distribution of erythrocyte potassium and sodium concentrations was studied in Sayaguesa (n = 150), Brown Swiss (n = 163) and two populations of Avileña-Negra Ibérica cattle (n = 141 and 141 respectively). No polymorphism was detected for red-cell cation content in any of the breeds investigated. Mean values of potassium concentrations varied between 21.42 and 24.92 mmol/l red cells, those of sodium contents ranging from 77.50-93.44 mmol/1. The cattle studied can thus be considered as belonging to the 'low potassium' (LK) type. Significant differences were found both in potassium and sodium concentrations between one of the populations of Avileña-Negra Ibérica and the other groups examined. Mean values of sodium levels in Brown Swiss were also significantly different from the other groups. ZUSAMMENFASSUNG: Verteilung von Kalium- und Natriumblutspiegelwerten in Erythrozyten einiger Rinderrassen Die Verteilung von Kalium- und Natriumkonzentrationen in Erythrozyten wurde in vier Gruppen untersucht: Sayaguesa (n = 150), Braunvieh (n = 163) und zwei Gruppen von Avileña-Negra Ibérica Rindern (n = 141). In keiner der untersuchten Gruppen wurde Polymorphismus für den Cationenspiegel gefunden. Mittelwerte für Kaliumkonzentration schwankten zwischen 21,4 und 24,9 mmol/l roter Zellen, die für Natriumgehalt zwischen 77,5 und 93,4 mmol/1. Die Rinder könnten daher als 'niedrigere Kalium' Type bezeichnet werden. Signifikante Unterschiede wurden sowohl für den Kalium-als auch für der Natriumspiegel zwischen den beiden Avileña-Negra Ibérica Gruppen gefunden. Die Mittelwerte für Natriumspiegel in Braunvieh waren ebenfalls significant unterscniedlich im Vergleich zu den anderen. RESUMEN: Distributión del potasio y sodio eritrocitarios en algunas razas de ganado vacuno Se estudió la distribución de las concentraciones de potasio y sodio eritrocitarios en cuatro grupos de ganado vacuno: Sayaguesa (n = 150), Pardo Alpina (n = 163) y dos poblaciones de Avileña-Negra Ibérica (n = 141 y n = 141). No se detectó polimorfismo en el contenido eritrocitario de cationes en ninguno de los grupos estudiados. Los valores medios de las concentraciones de potasio oscilaron entre 21.42 y 93.44 mmol/l de glóbulos rojos, mientras que los correspondientes al sodio oscilaron entre 77.50 y 93.44 mmol/l. Por tanto, los animates estudiados pueden considerarse como pertenecientes al tipo 'bajo potasio'. Se encontraron diferencias significativas entre el contenido en potasio y en sodio de una de las poblaciones de Avileña-Negra Ibérica y el resto de los grupos analizados. Además, los niveles medios de sodio eritrocitario de la raza Pardo-Alpina presentaron diferencias significativas con los demás grupos.

Monthly variation and distribution of erythrocyte Na, K and Mg concentrations in normal dairy cows

Blood samples were taken from the caudal vein of 64 normal dairy cows monthly for 12 months and the concentrations of erythrocyte Na (ENa), erythrocyte K (EK), and erythrocyte (EMg) were determined. The overall range of ENa concentrations in the cows was 16 to 176 mmol/l red cells with a grand mean (+/- SD) of 96 +/- 15.4 mmol/l, and a positively skewed distribution with a degree of skewness of 4.4. The overall range of EK concentrations was 13 to 99 mmol/l, with a grand mean (+/- SD) of 32.8 +/- 13.12 mmol/l red cells, and a distribution which suggested bimodality with modes at 26 and 70 mmol/l red cells. The overall range of EMg concentrations was 0.1 to 2.6 mmol/l red cells with a grand mean (+/- SD) of 0.99 +/- 0.12 and mode and median of 0.97 mmol/l red cells; the distribution was that of a normal Gaussian curve. Analysis of variance showed significant effects with respect to cows and calendar months but not lactation months on all cations (all P less than 0.01). The calendar months effects were similar for cows with mean erythrocyte K concentrations below 35 mmol/l for Friesians and Jerseys but not for Australian Illawarra Shorthorn cows. The repeatabilities were 0.4, 0.9 and 0.2 respectively for ENa, EK and EMg. It was concluded that ENa had a moderate genetic component, EK a high, and EMg a low genetic component. There was no significant correlation between plasma Na and ENA or plasma K and EK, but there was between plasma Mg and EMg (r = 0.21, df = 307, P less than 0.01).

The HK/LK polymorphism of erythrocyte cation content in two wild species of east African bovids: demonstrated in wildebeest but not in African buffalo

Concentrations of K and Na were determined in erythrocytes from wildebeest and African buffalo resident in Tanzania. The object was to determine if these species possess the HK/LK polymorphism which is typical of other bovid species, but not of other mammals. The polymorphism is characterized by individuals that are either of the HK phenotype (high K and low Na concentrations in red cells) or LK phenotype (low K and high Na concentrations in red cells). Wildebeest were shown to be polymorphic, with the distribution of phenotypes resembling that in domestic cattle. By contrast the polymorphism was not found in the African buffalo; all 59 individuals examined exhibited the HK phenotype. This was unexpected, since the polymorphism has been observed in five divergent bovid species, including two species (water buffalo and domestic cow) that are closely related to the African buffalo, and classified in the same subfamily (Bovinae). The most parsimonious interpretation of this pattern is that the trait was lost from the African buffalo after species in the Bovinae diverged. The biological significance of the HK/LK polymorphism, and reasons for its presence or absence among species in the Bovidae, remain obscure.

The effects of age on the erythrocyte sodium and potassium concentrations of dairy cows during late pregnancy and early lactation

Blood samples were taken at weekly intervals from 54 dairy cows (mainly Friesians and Jerseys) during the periods 8 weeks before and 8 weeks after calving. The cows were divided into two age groups; group 1 consisting of 26 cows aged 2 1/2 years and group 2 consisting of 28 cows aged 5-9 years. The changes in the erythrocyte sodium (ENa) and the erythrocyte potassium (EK) concentrations before and after calving were expressed as the slopes for each component regressed on weeks. In the older cows the concentration of ENa decreased (p less than 0.05) while that of EK increased (p less than 0.05) after calving. Both the ENa and EK concentrations varied significantly (p less than 0.01) between cows in the two age groups. The prepartum and postpartum ENa and the postpartum EK concentrations varied significantly (p less than 0.05) between weeks. EK type did not influence the changes in ENa or EK concentrations before or after calving.

Changes in concentrations of certain plasma and erythrocyte minerals associated with hypomagnesaemia in young calves

Hypomagnesaemia was induced in young calves 1-2 weeks old by feeding them with a diet composed of skimmed milk and barley straw to which urea, potassium chloride and soya-bean oil were added. Blood samples were collected from each calf once a week from the jugular vein until there was a significantly lower (P less than 0.01) plasma magnesium (PMg) concentration in the experimental compared to the control calves receiving MgO instead of KCl. In addition to PMg, the blood samples were analysed for plasma sodium, potassium, calcium, inorganic phosphate and erythrocyte concentrations of magnesium, sodium and potassium and red blood cell counts. The erythrocyte magnesium (EMg) concentration decreased significantly (P less than 0.01) in both groups. The decrease was, however, greater (P less than 0.05) in the magnesium deficient group than in the control group. Erythrocyte sodium (ENa) concentration increased and erythrocyte potassium (EK) concentration decreased in both groups, and the changes did not differ significantly between the two groups. Plasma concentrations of sodium (PNa) and potassium (PK) and red blood cell counts did not change significantly in either group. Significant (P less than 0.05) decreases in plasma calcium and inorganic phosphate concentrations occurred in the magnesium deficient group only.

Effects of age on erythrocyte magnesium, sodium and potassium concentrations in female dairy cattle

The effect of age on erythrocyte Mg, Na and K concentrations and the correlations between these parameters (EMg, ENa and EK) and other blood parameters were studied in female dairy cattle ranging from 1 week to over 8 years of age. EMg concentration was higher than plasma Mg, the concentration being highest in calves 1 week old and lowest in cows 3-4 years old. ENa and EK concentrations were lower and higher respectively in calves 1 week of age than in older animals and did not show any significant age variation in those between 1 and 8 years of age. The EK concentration was more highly correlated with erythrocyte parameters (PCV, RCC, Hb, MCV, MCH, MCHC) than was either EMg or ENa concentrations.

The response to potassium of the Na-K pump ATPase in low-K red blood cells from cattle at birth and in later life

It is shown that in low-K red blood cells of cattle the apparent affinity for K(1/Kapp K) at an inhibitory site of the Na-K ATPase increases markedly during the first 3 months of life. This site probably is the Na accepting site at the internal membrane surface and the change in Kapp K reflects an increase in KNa/KK, the ratio of the true dissociation constants. This effect may explain the concomitant fall in cellular K concentration.

Properties of a goat anti-L antibody: further evidence for heterogeneity of the L antigen

The preparation and properties of an antibody (anti-L) against low potassium type (LK) goat red cells raised in a high potassium type (HK) goat are described. This reagent stimulated active potassium transport, but showed only weak serological activity against low potassium type (LK) sheep and goat red cells. The results are discussed in relation to the hypothesis that anti-L antibody has two specificities--a sodium pump-stimulating activity (anti-Lp) and a serological activity (anti-L1y).