Regulatory peptides in milk, food and in the gastrointestinal lumen of young animals and children

Abstract

The present article reviews recent advances in our understanding of the regulatory role played by milk in the physiology of the neonate. Importance of milk bioactive proteins and peptides (BAPP) and their endogenous counterparts (hormones, gut regulatory peptides, growth factors) in the regulation of the development of the gastrointestinal tract (GIT) structure and function in the new-born is discussed. Mother's milk is often replaced with a milk formula that contains little or no BAPP. Although deprivation of milk BAPP is not lethal to the neonate, it affects GIT development processes, produces noticeable reduction of animal performance and lowers the resistance to GIT disorders. It is recommended that either the industrial processing is modified so as to avoid BAPP degradation or that the commercial milk formulas and weaning feeds should be supplemented with BAPP.

Development of gastrointestinal and pancreatic functions in mammalians (mainly bovine and porcine species): influence of age and ingested food

“…The length, diameter and weight of GI organs increase in the first days of life. Interestingly, the stomach, small intestine and pancreas of pigs as well as the forestomach and small intestine (but not the abomasum and pancreas) of calves and sheep grow disproportionately faster than the rest of the body, with the most intensive growth present within the first 24 h after birth [34,46,133,135,140,141] [63,129,130,136,144]. Before the gut is 'closed', large macromolecules may be absorbed [126].…”

Gut regulatory peptides as mediators of gastrointestinal tract growth, motility and development of secretion in young ruminants

“…Just after birth, the gut regulatory peptides present in colostrum and milk (Koldovky, 1989;Campana and Braumrucker, 1995;Zabielski, 1998;Bloom, 2005b) induce the postnatal development of the endocrine gut in controlling digestive functions until the endogenous regulatory systems are adequately developed. Thus, active or passive immunization against somatostatin results in an increase of growth (involving GIT) in the calf and lamb (Van Kessel et al, 1993;Van Kessel and Laarveld, 1994).…”

“…In calves fed milk replacer based on skim milk proteins, feeding is followed by a long lasting increase of plasma gastrin and CCK, and a decline in secretin, motilin and somatostatin (Guilloteau et al, 1986b;Toullec et al, 1992;Le Dréan et al, 1997, 1998, 2000Zabielski et al, 1998). Plasma PP shows a biphasic pattern, a transient peak related to suckling is followed by a long lasting inhibition ).…”

“…Thirdly, intravenous infusions in a physiological range of these gut regulatory peptides can stimulate the secretion of pancreatic juice rich in fluid and bicarbonates for the secretin/VIP family and juice rich in enzymes for the CCK/gastrin family (Davicco, 1978;Pierzynowski et al, 1991;Le Dréan et al, 1997, 1998, 2000Zabielski et al, 1992; Figure 3). During the interdigestive periods, CCK and gastrin stimulate pancreatic exocrine secretion and these effects are partly mediated by the CCK 2 receptor.…”

Bioactive peptides in young animal nutrition

“…Table 1 shows some known bioactive peptides derived from milk protein and their biological activity. Since milk replacers and feed- (Kostyra and Kostyra, 1992;Wong et al, 1996;Meisel, 1997Meisel, , 1998Rudloff and Kunz, 1997;Schanbacher et al, 1997;Tirelli et al, 1997;Dziuba et al, 1999;Yamamoto and Takano, 1999) (Rao, 1991;Koldovsky et al, 1995;Smith-Kirwin et al, 1998;Xu, 1998;Zabielski, 1998) …”