Lingual lipase | Detected by GW 26 and detected at birth with subsequent decline (Hamosh et al., 1981; Fredrikzon et al., 1982; Smith et al., 1986; Lee et al., 1993) | Primary source of lipase activity at birth; mouse is similar (Henning, 1981; DeNigris et al., 1988) | Not specifically described | For neonatal guinea pigs, rabbits and baboons, low or no activity detected (DeNigris et al., 1988) |
Salivary amylase | Low levels present prenatally and at birth; adult levels achieved by 3 mo of age (Sevenhuysen et al., 1984; Shibata et al., 2013; García-Blanco et al., 2016) | Not detected until second postnatal week, with substantial increase at weaning (Redman and Sreebny, 1971) | Not specifically described | Not specifically described for other species used for nonclinical drug development |
Gastric lipase | Detected by GW 26 and primary source of lipase activity at birth for term and preterm infants; subsequent decline postnatally (Sarles et al., 1992; Ménard et al., 1995; Armand et al., 1996) | Negligible activity at birth for both rats and mice (DeNigris et al., 1988) | Highest in neonatal period then declines after weaning (Li et al., 2001) | Primary source of lipase activity in neonates of most nonrodent species (pig, dog, rabbit, guinea pig, baboon) (DeNigris et al., 1988; Iverson et al., 1991; Carrière et al., 1992) |
Gastric pepsin | Present and active at birth; but lower expression and activity than adults; activity increases after initiation of oral feeding (Wagner, 1961; Agunod et al., 1969; DiPalma et al., 1991; Armand et al., 1996) | Not detected until second postnatal week, then activity increases through weaning (Deren, 1971; Furihata et al., 1972; Henning, 1981) | Low at birth but gradual increase after 1st week postnatal (Cranwell, 1985), and substantial increase at 3 wk (Cranwell, 1985; Smith, 1988) | In ferrets, low at birth with gradual rise during first 3 wk postnatal (Hamosh et al., 1998); in rabbits and dogs, low or no activity until ∼3 wk (Buddington et al., 2003) |