TABLE 6

Ontogeny of pancreatic digestive enzymes

EnzymeHumanRatPigOther
Pancreatic amylaseNegligible activity prenatally  and at birth but detected by  1 mo postnatally and  reaches adult levels by  weaning (Lebenthal and  Lee, 1980)Present at birth for first feeding, but  then steep decline (Robberecht  et al., 1971; Mubiru and Xu, 1998)Rapid increase postnatally in  pigs (Mubiru and Xu, 1998)In dogs, first detected after 3 wk,  but relatively low through  weaning (Buddington et al.,  2003)
Pancreatic lipaseNegligible at birth (Lebenthal  and Lee, 1980)Present at birth for first feeding, but  then steep decline until weaning  (Robberecht et al., 1971; Mubiru  and Xu, 1998)Present and active at birth in pigs  with steep increase in activity  at 3–4 wk; primary source of  lipase activity (Pierzynowski  et al., 1995; Jensen et al., 1997;  Mubiru and Xu, 1998; Li et al.,  2001)Not detected until 6 wk, but  reaches adult levels by 9 wk  postnatal (Buddington et al.,  2003)
Carboxypepdidase BRelatively low prenatally and  at birth (Lebenthal and  Lee, 1980)Not specifically reported
TrypsinPresent and active from birth  (Lebenthal and Lee, 1980)Present and presumed active at  birth for first feeding, but then  steep decline until weaning  (Robberecht et al., 1971; Mubiru  and Xu, 1998)Present and active at birth, with  increased activity postnatally  (Harada et al., 1988; Jensen  et al., 1997; Mubiru and Xu,  1998)In dogs, relatively high activity  during suckling (Buddington  et al., 2003)
ChymotrypsinPresent and active from birth  (Lebenthal and Lee, 1980)Present at birth for first feeding,  but then steep decline until weaning  (Robberecht et al., 1971; Mubiru  and Xu, 1998)Present and active at birth with  increased activity postnatally  (Harada et al., 1988; Jensen  et al., 1997; Mubiru and Xu,  1998)Low at birth in dogs, with increase  through 3 wk postnatal, and  secondary increase after weaning  (Buddington et al., 2003)