Arch Dis Child: first published as 10.1136/adc.36.190.604 on 1 December 1961. Downloaded from SERUM ENZYME ACTIVITY IN THE NORMAL NEWBORN INFANT BY J. KING and M. BRENDA MORRIS From the Pathology and Paediatric Departments, North Lonsdale Hospital, the Barrow and Furness Hospital Group (RECEIVED FOR PUBLICATION APRIL 14, 1961) The assay of serum enzymes has been used (diphosphopyridine nucleotide-DPN) as hydrogen increasingly in recent years as an aid to clinical carrier and exhibit greatest activity in the reactions diagnosis and prognosis, but the literature contains summarized by equations (iii) and (iv). few references to the exploitation of these laboratory COO- COO- tests in paediatrics. Following the development in these laboratories (iii) H-C-OH + DPN LDH_ C==O + DPNH2 of assay procedures for glutamate-oxalacetate CH3 CH3 transaminase (GO-T), glutamate-pyruvate trans- (lactate) (coenzyme l) (pyruvate) (reduced coenzyme 1) aminase (GP-T), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) suited to routine COO- COO- work, the determination of the normal serum activities of these enzymes in the neonatal period H-C-OH MDH C O (iv) + DPN _ + DPNH2 copyright. was undertaken in conjunction with an investigation CH2 - CH2 of the usefulness of their estimation in haemolytic disease of the newborn. COO- C00- The transaminase enzymes form a link between (malate) (coenzyme 1) (oxalacetate) (reduced coenzyme 1) protein and carbohydrate metabolism and mediate Methods and Materials in the reactions shown in equations (i) and (ii). Glutamate-oxalacetate transaminase (GO-T) and COO- COO- COO- COO- glutamate-pyruvate transaminase (GP-T) activities were estimated by the methods of King (1960a). As the H-C-NH2 LO H C NH2 colorimetric procedures for the assay of serum lactate C-=O http://adc.bmj.com/ (I) I GO-T dehydrogenase (King, 1959, 1960b) and malate dehydro- CH2 + CH2 O-CH2 + CH2 genase (King, 1961) are rapid and require small quan- tities of serum they were found to be suited to the present LO0 CH2 COO- CH2 survey. were COO- COO- Bilirubin levels determined by a micro adaptation (glutamate) of the method of Malloy and Evelyn (1937), checked on (aspartate) (a-oxoglutarate) (oxalacetate) numerous occasions when the sample permitted by the COO- COO- COO- COO- spectrophotometric technique of Scott (1959). Good agreement was obtained between the two methods. The H-C-NH2 C0= C=O H-C-NH2 latter procedure was found to give an indication of on October 2, 2021 by guest. Protected (') +1I GP-T + degree of haemolysis which in icteric serum is sometimes CH3 CH2 _ CH3 CH2 difficult to decide by inspection. The material consisted of 154 cord bloods and 41 CH2 - CH2 specimens of blood taken from normal full-term infants COO- COO- on one occasion during the first nine days of life. Since (alanine) (a-oxoglutarate) (pyruvate) (glutamate) GO-T and GP-T activities for whole blood are approxi- mately five and three times respectively those of serum, while for LDH and MDH the ratio ranges from 100 to Lactate dehydrogenase is a glycolytic enzyme and 150, specimens showing any visible haemolysis were dis- malate dehydrogenase catalyses the final step in the carded for purposes of dehydrogenase assay and only the tricarboxylic acid cycle. These biocatalysts, as slightest haemolysis was tolerated for the determination found in human blood serum, require coenzyme I of transaminase activity. 504 Arch Dis Child: first published as 10.1136/adc.36.190.604 on 1 December 1961. Downloaded from SERUM ENZYME ACTIVITY IN NORMAL NEWBORN 605 TABLE 1 a factor 1 * 5 to 2* 5 than the respective figures found NORMAL CORD BLOOD VALUES in normal adults. GP-T on the contrary was found to have a narrower and lower range. MDH was 98_ Standard Observed Adult found to parallel LDH so closely, the ratio of acti- Mean Deviation Values Range vities approximating to 1: 6, that it is not proposed Bilirubin (mg./100 ml.) .. 1-86 ±0-51 06-3 4 <1-0 to treat it separately. GO-T(lnternationalunits) 15-1 ±4-1 6-25 6-18 GP-T (International units) 5*5 ±2*5 1 3-11 3*5-15*5 Figs. 1 to 3 are scattergrams showing the relation LDH (International units) 330 ±82 150-590 70-230 MDH(Internationalunits) 52-5 ± 13 22-5-98 10-44 30 -T Cord blood was obtained by letting the blood drip from the maternal end of the cut cord into the collecting U)i ,- 25± bottle, and the subsequent specimens from the babies . were obtained by puncture of a scalp vein. All babies in the normal series were full-term babies z .* so of birth weight over 5 lb. 8 oz. In the case of the 154 -J . ** * babies whose cord bloods were taken, there was no z 20± 0 0 0 cr abnormal jaundice in the neonatal period, and in the case 0 O0* * 0 0 of the 41 babies whose blood was taken at some time Lljz * 0 in the first nine days of life, every baby was personally S so "D *so observed by one of us (M.B.M.) throughout the first 0 .a_ . 10 days of life, and their course was I5 + this * s"_ 0 during time * _ 00 r. normal. 0 0 0 I- I- In all cases both mothers' and infants' blood groups . 0SSe . z s 0 were determined and in the 41 infants from whom a * second blood specimen was obtained the direct Coombs .*s 0 0 0 00 * test was negative. lot 0 * 0 000 00 00 * so C) copyright. Results m O * 0*s Cord Blood. The statistical analysis of figures 0 0* In 5 t for the normal cord blood serum is presented in Table 1, together with normal adult values obtained using the same methods. The units originally used in this work were those defined by Antebi and King I (1958), but recently an international enzyme sub- 2 3 4 5 commission has recommended the use of an Inter- SERUM BILIRUBIN [mg./lOOml.] national Unit (King and Campbell, 1961) for http://adc.bmj.com/ FIG. 1.-Variation expressing serum enzyme activity and the results of cord GO-T activity with bilirubin. obtained in the present study are recorded in Inter- national Units. This unit is that which will STF transform lu mole of substrate per minute under z the prescribed assay conditions, activity to be 0 expressed per litre. 10n 0 0. Similar to the figures obtained in the > ) r, adults, 0 Z IlO- 0 0 . distributions of all these cord blood enzyme I0 on October 2, 2021 by guest. Protected * 0 0* c activities are found to be of the 'log normal' type * J ** OS* " (Gaddum, 1945) and positively skewed. A normal '0 * - * * s z range in terms of mean and standard deviation 0 so"so a" 00 >z 5- * * *0 5" Cl cannot be * _a"so os s * so * * expressed under * these circumstances and "* * * of _**m* * following the arguments of Wootton and King nw (1953) the range so 00 0 is best expressed by upper and lower * 0 04M0_ * Se0 1% limits which enclose 98% of the distribution. 0 Figures falling outside these limits may be regarded 2 3 4 as abnormal. It is seen that for GO-T, LDH and MDH the SERUM BILIRUIBIN [mg./ 100 ml.) range of values encountered is wider and higher by FIG. 2.-Variation of cord GP-T activity with bilirubin. Arch Dis Child: first published as 10.1136/adc.36.190.604 on 1 December 1961. Downloaded from 606 ARCHIVES OF DISEASE IN CHILDHOOD 7007T between serum enzyme activity and bilirubin 0 levels. These show, not unexpectedly, that there is no correlation between serum bilirubin and any en 600- of these enzymes. I- t No correlation between any of the five biochemical -i parameters studied, with the exception of LDH 4 and MDH, was found, and no significant difference z soo--I- 0 with sex of the infant could be demonstrated. I- * 0 @0 z The values for normal cord blood GO-T and GP-T activities, together with cord blood figures - 400- * * z 0. obtained in some premature infants are shown in * 0 *mm Figs. 4 and 5 plotted against gestation period me. * 0 -- weight. LDH and MDH emoe irrespective of birth - 300 - @0 * o: *-e*0 * :0 @ patterns were similar to that for GO-T inasmuch as .: normal cord blood range * 0 0 all values fell within the * * 0 0- with no obvious change in distribution. GP-T I 4 200-1 @* 0 a activity, however, did appear to show some decrease r Z * 0 with premature delivery, but the number of the 0 O 4AJ, m sample is too small to demonstrate any significant Z > 100 ± C) r, change. m I Newborn Infants. The results obtained Normal ____ __ from enzyme assays of the 41 'second' specimens, 1 2 3 4 5 together with the respective cord blood figures are SERUM BILIRUBIN (mg./1OOml.] summarized in Figs. 6 to 8 where enzyme activity FIG. 3.-Variation of cord LDH activity with bilirubin. is plotted against day of life. For GO-T and LDH copyright. 30 -r U) 0 25 t 0 0 z4 4 * 0 00 z 20+ meG http://adc.bmj.com/ 0 I-z * 0 0 f 0 I so so *0 IsI 0 0 *= 0 0 so 0 -_ -.. V 40 soe _ee __ee I0o~ on October 2, 2021 by guest. Protected U) 0 0 0 so 0 * 40 5s 0 33 34 35 36 37 38 39 40 41 42 GESTATION [WEEKS] FIG. 4.-Variation of cord GO-T activity with gestation.