Plasma gastrin in the pig from birth to weaning.

Mean (+/- SEM) plasma gastrin concentration was measured as 84.4 +/- 7.0 pmol litre-1 by radioimmunoassay in 35 newly born pigs within one hour of birth but, two-and-a-half hours later, after sucking, it had decreased to 34.9 +/- 3.6 pmol litre-1. Significant increases (P less than 0.01) in the concentration of plasma gastrin occurred in the three weeks after birth to 142.5 +/- 13.2 pmol litre-1 at one week, 174.8 +/- 15.7 pmol litre-1 at two weeks and 91.4 +/- 9.6 pmol litre-1 at three weeks after birth. On weaning, at four weeks old, plasma gastrin concentration was 26.0 +/- 1.7 pmol litre-1 and at five and six weeks old it was 56.7 +/- 4.4 and 54.7 +/- 3.9 pmol litre-1, respectively.