Serum alkaline phosphatase adult levels

A steady decline in serum alkaline phosphatase activity toward adult values is seen in late adolescents of both sexes (Fig. 3). This process begins at approximately 11 years of age in females (F13), so that by the time they reach their twentieth year, their levels are almost indistinguishable from those of older females. In males, the decline toward adult values commences later and is more prolonged, so that levels do not merge into those of older adult males until well into the third decade (C22, F13, K23, K33). 

Percy Veere s laboratory studies showed that his serum alanine transaminase (ALT) level was 294 units/L (reference range = 5-30), and his serum aspartate transaminase (AST) level was 268 units/L (reference range = 10-30). His serum alkaline phosphatase level was 284 units/L (reference range for an adult male = 40-125), and his serum total bilirubin was 9.6 mg/dL (reference range = 0.2-1.0). Bilirubin is a degradation product of heme, as described in Chapter 44. 

As a brief introductory summary, vitamin D substances perform the following fundamental physiological functions (1) promote normal growth (via bone growth) (2) enhance calcium and phosphorus absorption from the intestine (3) serve to prevent rickets (4) increase tubular phosphorus reabsorpiion (5) increase citrate blood levels (6) maintain and activate alkaline phosphatase m bone (7) maintain serum calcium and phosphorus levels. A deficiency of D substances may be manifested in the form of rickets, osteomalacia, and hypoparathyroidism. Vitamin D substances are required by vertebrates, who synthesize these substances in the skin when under ultraviolet radiation, Animals requiring exogenous sources include infant vertebrates and deficient adult vertebrates, Included there are vitamin D (calciferol ergocalciferol) and vitamin D< (activated 7-dehydrocholesterol cholecalciferol). 

In 1950 Seligman and his co-workers (S13) suggested the use of sodium j8-naphthyl phosphate as a substrate for the determination of acid or alkaline phosphatase activity. For the former, 1 ml of 1 20 diluted serum was added to 5 ml of 0.4 mM sodium 8-naphthyl phosphate in 0.1 M acetate buffer of pH 4.8, and the reaction was allowed to proceed for 2 hours at 37.5°C. The addition of 4 drops of IM sodium carbonate solution served to retard the reaction as well as to raise the pH to the optimal level for coupling with 1 ml of a solution of tetrazotized ortho-dianisidine. After 3 minutes, the protein was precipitated with trichloroacetic acid, the dye extracted with ethyl acetate, and the color density determined in the region of 540 nm. The unit of phosphatase activity was defined as that amount of enzyme which liberates the color equivalent of 10 ml of j8-naphthol per hour at 37.5° in 1 hour. The serum acid phosphatase in a group of normal adults ranged from 0.7 to 1.6 units and averaged 1.0 unit per 100 ml of serum. 

Osteomalacia is most often seen during pregnancy and lactation and is characterized by osteoporosis, deformity and fracture of bones, and tetany. The concentration of calcium in serum is low, often less than 7 mg. per 100 ml., and the level of alkaline phosphatase is elevated above the usual adult value of 3 to 5 units. 

Regarding the effect of anticonvulsants on calcium metabolism, the potential size of the problem was highlighted by Richens and Rowe (34 ) who showed that 22.5% of epileptic patients in an adult residential centre had decreased serum calcium levels, and 29% had increased alkaline phosphatase levels. Lemaire et al. (24 ) studied a case of osteomalacia due to anticonvulsants using tritium-labelled vitamin D. It was shown that its metabolism was accelerated in comparison with deficiency type osteomalacia. This supports the hypothesis that anticonvulsants, acting via hepatic enzyme induction processes, cause increased transformation of vitamin D into inactive metabolites. Richens states that it is likely that anticonvulsant osteomalacia is caused by a disturbance of the hepatic hydroxylation of vitamin D3 to... 

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