摘要:

The ability of the fetal pig intestine to absorb large proteins was investigatedin utero. Six pregnant sows were anesthetized (Na pentobarbital) at 99-102 d of gestation (term = 115 ± 2 d), and a catheter was inserted into the esophagus of two to three fetuses per sow. Via these catheters, sterile solutions (10.0 mL) of colostrum whey (CW,n= 5), milk whey (MW,n= 5), or amniotic fluid (AF,n= 4) were infused into the fetal pig stomachs every 6 h for 6-8 d starting on the day after surgery (d 0). Levels of IgG in the three fluids were 120, 0.5, and 0 mg/mL, respectively. During the first 2-3 d of infusion, plasma IgG levels rose rapidly in the CW fetuses (to 7.5 ± 0.8 mg/mL), whereas IgG remained absent in plasma from MW and AF fetuses. Absorption of a macromolecule marker, BSA, was also higher when the marker was given with CW rather than with MW or AF. However, when all three treatment groups were given CW + BSA on the last experimental day (d 6-8), the mean BSA increment in the CW group was only 5-8% of that in the AF group, with intermediate values for the MW group. Neither at the beginning nor at the end of the experiment was macromolecule uptake in individual CW fetuses correlated with their cortisol level in plasma. The prenatal pig intestine is similar to the neonatal pig intestine in that colostrum stimulates both the macromolecule absorption and the cessation of macromolecule uptake (intestinal closure). However, fetal pigs have a lower protein absorptive capacity and a longer preclosure period than newborn pigs; this may be related to an immature structure and function and a slow enterocyte proliferation rate in the prenatal pig intestine.

ISSN:0031-3998    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Unusual bile acids, such as unsaturated ketonic and 7β-hydroxylated bile acids, have been detected in urine early in life. To elucidate the normal profiles of usual and unusual urinary bile acids in the neonatal and pediatric periods, we measured the concentrations of 28 kinds in urine from normal newborns, infants, and children by gas chromatography-mass spectrometry. The mean total bile acid/Cr ratio in 7-d-old infants was significantly higher than in subjects of other age groups (birth, 2-4 mo, 5-7 mo, 11-12 mo, 2-3 y, 9-14 y, and adult) (p< 0.05). Relatively large amounts of unusual bile acids were detected during infancy, especially during the period up to 1 mo of age. At that time, 1β,3α,7α,12α-tetrahydroxy-5β-cholan-24-oic, 7α,12α-dihydroxy-3-oxo-5β-chol-1-en-24-oic, and 7α,12α-dihydroxy-3-oxo-4-cholen-24-oic acids were predominant among the unusual urinary bile acids present. Moreover, the levels of 3α,7β,12α-trihydroxy-5β-cholan-24-oic acid increased significantly after 2-4 mo of age. These results indicate that bile acid synthesis and metabolism in the liver of developing infants are significantly different from that occurring in the liver of adults. Significant amounts of urinary isomerized 7β-hydroxylated bile acids were detected after late infancy, probably because of changes in the intestinal bacterial flora response to a change in nutrition. We describe, for the first time, evidence of the epimerization of the 7α-hydroxyl group of cholic acid, which may be unique to human development.

ISSN:0031-3998    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1999

数据来源: OVID