Synthesis of α-Fetoprotein, Albumin and Total Serum Protein in Neonatal Pigs

Abstract

Studies on the incorporation of ³H-leucine established that synthesis of α-fetoprotein (AFP) does occur in the neonatal pig. This synthesis probably accounts for the increase in AFP concentration from 0.46 mg/ml on the day after birth to the maximum value of 1.02 mg/ml found 5 days after birth. After the 5th day, the concentration decreases successively and AFP cannot be detected by electroimmunoassay in the sera of 8-week-old pigs. During the first 3 weeks of extrauterine life, the albumin concentration in serum increases from 3 mg/ml to approximately 30 mg/ml due mainly to increased synthesis of albumin. The concentration of AFP in the fetal pig serum decreases from 3 mg/ml at 6.5 cm crown-to-rump (CR) length to 0.8 mg/ml at 28 cm CR length, whereas the albumin concentration increases from 0.2 mg/ml at 6.5 cm CR length to 1.0 mg/ml at 28 cm CR length. The total serum protein content in the fetus is approximately 20 mg/ml irrespective of gestational age. During the first day after birth there is a marked increase in both the synthesis and the concentration of total serum proteins. The concentration rises to 70 mg/ml during the first day and then slowly declines to 65 mg/ml during the 3 weeks following birth.

Proteins in Cerebrospinal Fluid and Plasma of Fetal Pigs during Development

“…Some of our results confirm those of previous authors over a more restricted range of gesta tion on total protein, albumin and AFP in fe tal pig serum [10,22,24,36], Transferrin and fetuin do not appear to have been estimated previously in fetal pig plasma nor are there any quantitative studies available of proteins in fetal pig CSF.…”

“…These authors found a value of only 100±56 mg/100 ml for serum transferrin in newborn piglets, which subsequently rose to adult lev els by 3 weeks postnatal. It is not clear if there is a gradual decline from approximately 500 mg/100 ml at 109 days (table II) to a newborn value of less than 200 mg/100 ml [37], There may be a sudden drop at the time of birth as is the case for AFP [22]. In contrast, there is a very marked rise in serum albumin concen tration in the newborn and postnatal period in the pig [22].…”

“…The pig fetus is also interesting because like the sheep, fetuin is a predominant plasma and CSF protein for much of gestation [14]; how ever, no quantitative estimate of fetuin in the pig has been obtained previously. In addition the pig is unlike other fetuses so far examined in that its serum albumin level is low through out gestation in relation to total protein con centration [22,36].…”

Perinatal Development of Tubular Function in the Pig

“…Plasma proteins in the developing pig have been studied extensively by Ingvarsson, Carlsson & Karlsson (1978), who described an increased synthesis of albumin in the new-born pig. Stone (1981) found that during fetal growth a-fetoprotein declined as albumin increased.…”

Immunoresponsiveness of Newborn Piglets and Peptidoglycan Derived from Bifidobacteria

“…Recently Carlsson et al (7), Ingvarsson et al (13) have observed that neonatal piglets produce a relatively high amount of afetoprotein. This fact suggested that some physiological condition of suckling piglets seems to be at a fetal stage.…”