[Cholinesterase activity and protein concentration in the serum of premature and newborn infants].

Cholinesterase activity and concentrations of total protein, albumin and globulins were measured in the serum of 94 carefully selected prematures and newborns during the first week of life. Cholinesterase activity was significantly lower in prematures than in newborns. There was a weak correlation between serum concentration of albumin and cholinesterase activity. Total protein, albumin and gamma-globulins were significantly lower in premature babies. With the exception of alpha-1-globulin, all proteins correlated positively with gestational age. There was no difference in total serum protein concentration between small for gestational age infants and appropriate for gestational age infants. Postnatally, serum protein and cholinesterase activity rose by 27 44% within 7 to 10 weeks in prematures of 30-33 weeks of gestational age. A single infusion of 0.5 g/kg b.w. albumin transiently increased the protein concentration of prematures 1.5 fold; 7 to 10 weeks later, protein concentrations of treated and untreated prematures were no longer different. In conclusion, cholinesterase activity and protein concentrations correlated with gestational age. In prematures with disturbed microcirculation, albumin infusions resulted in a transient increase of protein concentration.