Plasma alkaline phosphatase

Domestic sheep (Ovis aries) fed a low-zinc diet (2.2 mg Zn/kg DW diet) for 50 days, when compared to those fed a zinc-adequate diet (33 mg Zn/kg DW diet), excreted less zinc (<4 mg daily vs. 23 to 25), consumed less food (409 g daily vs. 898), and had lower plasma zinc concentrations (0.18 mg/L vs. 0.53 to 0.58) a reduction in plasma alkaline phosphatase activity and an increase in plasma zinc binding capacity were also noted (Khandaker and Telfer 1990). Sensitive indicators of zinc deficiency in lambs include significant reductions in plasma alkaline phosphatase activity and plasma zinc concentrations signs were clearly evident in lambs fed 10.8 mg Zn/kg DW diet for 50 to 180 days (Vergnes et al. 1990). A normal diet for lambs contains 124 to 130 mg Zn/kg DW ration vs. 33 for adults (Vergnes et al. 1990). One recommended treatment for zinc-deficient sheep is ruminal insertion of zinc-containing boluses every 40 days bolus zinc release is about 107 mg daily (Khandaker and Telfer 1990). 

In a recent study 1 of over 600 children and adults from birth to 27 years of age, Clark and Beck found that the levels for each individual are characteristic and tend to remain about the same year after year. They conclude that "a single sampling every year would, generally speaking, be sufficient to classify a child regarding plasma alkaline phosphatase activity." The over-all range in the tabulated data... 

Registration of adverse effects with Lorenzo s oil has been hampered by the absence of controlled trials. In 22 patients treated for at least 12 months, although Lorenzo s oil did not seem to be beneficial, there were possible adverse effects, such as mild increases in liver enzymes (55%), thrombocytopenia (55%), gastrointestinal complaints (14%), and gingivitis (14%). Furthermore, there were falls in hemoglobin concentration and leukocyte count, and an increase in the plasma alkaline phosphatase concentration the reduction in platelet count did not result in hemorrhage (1). Whether some of the adverse effects of Lorenzo s oil are due to low concentrations of essential fatty acids or caused by reduced dietary fat intake is not known. 

During the past two decades, essentiality of zinc for man has been established. Deficiency of zinc in man due to nutritional factors and several dls-seased states, has been recognized. A marginal deficiency of zinc appears to be prevalent in many segments of population in developed countries and more severe deficiencies are widespread in many parts of the world. In our experimental human model, a marginal deficiency of zinc was induced by dietary means. Loss of body weight (less than 10% in six months on zinc restricted diet), testicular hypofunction, hyperammonemia and a decrease in plasma, urinary and neutrophil zinc concentration were observed. Changes in zinc dependent enzymes such as deoxythymldine kinase in newly synthesized connective tissue and plasma alkaline phosphatase were also observed as a result of zinc restriction and repletion in our model. 

Plasma alkaline phosphatase was monitored carefully In the second group of subjects. In both cases, the activity slowly declined as a result of zinc restriction, and after supplementation with zinc, the activity nearly doubled In 8 weeks. In all four subjects, the activity of plasma rlbonuclease was almost twice as great during the zlnc-restrlcted period as In the zinc-supplemented phase. Plasma lactic dehydrogenase activity de-... 

Rosalkl, S.B., Foo, A.Y., Dooley, J.S. Benign familial hyperphosphat-asaemie as a cause of unexplained increase in plasma alkaline phosphatase activity. J. Clin. Pathol. 1993 46 738 - 741... 

These data indicate that plasma alkaline phosphatase and deoxythymidine kinase in sponge connective tissue in human subjects are zinc-dependent enzymes inasmuch as changes in their activities were related to only one dietary manipulation, namely zinc intake. Changes in the activities of plasma RNase also appear to be related to zinc intake under the conditions of our experiments. Thus the determination of the activities of these enzymes may be helpful in correlating uncomplicated zinc status in man, particularly if the changes are observed following zinc supplementation for a short period of time. 

Also, Hodson et al. (H17) applied Smithies technique for the characterization of alkaline phosphatases from different tissues (intestine, liver, bone, etc.). In their report they questioned the contention that the osseous system is the main contributing source of human plasma alkaline phosphatase (H17), and preferred liver alkaline phosphatase as the main fraction of serum alkaline phosphatase. Hodson et al. (H17) observed the occasional presence of alkaline phosphatase at the intestinal region also in sera after electrophoresis. 

C9. Clark, L. C., and Beck, E., Plasma alkaline phosphatase activity, I. Normative data for growing children. J. Pediat. 36, 335-341 (1950). 

D12. Dent, C. E., and Harper, C. M., Plasma alkaline phosphatase in normal adults and in patients with primary hyperparathyroidism. Lancet I, 559 (1962). 

Fig. 2. Plasma alkaline phosphatase values in children and adolescents plotted as moving geometric means. Each mean is based on data from 80 children. The next mean is based on data from the 30 oldest of these 80, plus the next 50 in order of age. The solid circles denote males, the open circles females. The upper reference limit for adults obtained by the method employed was 256 U/liter. Note that the peripubertal rise occurs later in boys and is more pronounced than in girls. From Fleisher et al. (F13) with permission.

C24. Cohen, R. D., and Vince, F. P., Pseudohypoparathyroidism with raised plasma alkaline phosphatase. Arch. Dis. Child. 44, 96-101 (1969). 

Eade, M. N., Cooke, W. T., and Williams, ]. A., Liver disease in Crohn s disease, A study of 100 consecutive patients. Scand.. Gastroenterol. 6, 199-204 (1971). Eaton, R. H., Plasma alkaline phosphatase assay. Interconversion of results by two methods. Clin. Chem. 23, 2148-2150 (1977). 

Gardner, M. D., and Scott, R., Frequency distribution and reference values of plasma alkaline phosphatase (EC 3.1.3.1) activity in the adult population of a Scottish new town. J. Clin. Pathol. 31, 1202-1206 (1978). 

Serum isozymes following different types of injuries. The multimolecular forms of enzymes, called isozymes, may be identified using combinations of suitable gel electrophoresis and histochemistry. The changes in naphthylamidase and alkaline phosphatase following burns most likely indicate an alteration of liver metabolism and may persist for several weeks (A5). A rise in plasma alkaline phosphatase, but of kidney origin, can be found after limb ischemia in the rabbit. 

Except for elevation of plasma alkaline phosphatase by enzyme released from the placenta (B24, W17), other biochemical indices of liver function are usually normal in pregnancy though very occasionally pregnancy may be associated with cholestatic jaundice (K2, S28, S47), possibly conditioned by a genetic factor (H21). 

Despite the postulated connection between parathyroid hormone activity and citric acid metabolism, plasma citrate concentration is normal in cases of hyperparathyroidism unless there is active bone disease present, in which case it may be raised (Wl). Plasma alkaline phosphatase is also raised only in the presence of active osteitis fibrosa. 

Given the tissue and cellular variations, it is not surprising to find marked differences in plasma enzymes between species (Lindena and Trautschold 1986). For example, plasma alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities show greater variability in rats and monkeys when compared to man therefore, they have a poorer predictive or diagnostic value in these species. In young animals, the osseous ALP isoenzyme is the dominant plasma form in most species,... 

Alkaline phosphatase (ALP) is present within biliary and canalicular membranes, kidney, intestine, and bone therefore, ALP is not specific for the liver. Plasma alkaline phosphatase (ALP) can be used as a measure of cholestasis (Moss 1982 Schlaeger, Haux, and Katterman 1982), although the high intestinal proportion in the rat and the intra- and intervariability in nonhuman primates reduce its diagnostic value. 

Alkaline phosphatase. The effects of food intake on plasma alkaline phosphatase in the rat have been mentioned in Chapter 2. For this species with a much larger proportion of intestinal isoenzyme in plasma, changes of plasma alkaline phosphatase can indicate gastrointestinal toxicities. 

Plasma alkaline phosphatase also changes during growth periods, but it is not a useful marker of bone metabolism in rats or nonhuman primates (see Chapter 2). 

Sequential biochemical measurements could complement such clinical trials. Demonstration of an increasing concentration of plasma zinc is evidence of effective zinc absorption and patient compliance. A rise in the activity of plasma alkaline phosphatase is... 

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