Induction of precocious intestinal maturation in T-cell deficient athymic neonatal rats

Abstract

AIMTo investigate whether gut maturation could be induced precociously in an athymic T-cell deficient neonatal rat model.METHODSFourteen day-old athymic (nude) rats (NIH-Foxn1rnu) were gavaged with either phytohaemagglutinin - a lectin from red kidney beans (PHA); trypsin - a protease (Prot); or water - vehicle (control) as a single dose on one day or once a day for 3-day. The nude rats were either nurtured by their mothers or cross-fostered by conventional foster dams of the Sprague-Dawley strain from days 3-5 after birth. At 17 d of age, 72 h after administration of the first treatment, intestinal macromolecular permeability was tested in vivo, prior to euthanasia, after which blood and gut organs were sampled.RESULTSProvocation with both, PHA and protease, resulted in increased gut growth and maturation in nude rat pups independent of nursing. Foetal-type enterocytes were replaced by non-vacuolated adult-type enterocytes in the distal small intestine epithelium. Decreased intestinal macromolecular permeability (gut closure) was observed, with reduced permeability markers (BIgG and BSA, P < 0.001) in circulation. Increased pancreatic function, with an increased trypsin to protein ratio in pancreas homogenates, was observed independent of nursing in the nude pups. Immunostaining showed the presence of a few CD3+-cells in the intestinal mucosa of the nude pups. The number of CD3+-cells remained unaltered by provocation and no differences were observed between the nursing sets. Growth and vitality of the nude pups were dependent on nurturing, since cross-fostering by conventional dams increased their macromolecular absorptive capacity (BSA, P < 0.05), as well as their passive immunity (RIgG, P < 0.05).CONCLUSIONPrecocious gut maturation can be induced by enteral provocation in athymic rat pups, similarly to in euthymic pups, thus showing an independence from thymus-derived T-cells.

Infant Formula Supplemented with Biotics: Current Knowledge and Future Perspectives

“…Gut permeability measured by fluorescein isothiocyanate-dextran was similar in mice receiving post- and prebiotics and mother-fed mice, while it was significantly lower in mice receiving the control infant formula without post- or prebiotics ( Figure 4 ). An early decrease in permeability, as observed in the control group, could have a lasting detrimental effect on health by changing immune maturation [ 127 ].…”

Early effects on the intestinal barrier and pancreatic function after enteral stimulation with protease or kidney bean lectin in neonatal rats

“…Control pups received the vehicle, water, administered at a volume of 0·01 ml/g b.wt. The dosage of PHA and protease was established in previous studies and considered as effective doses by the capacity to induce precocious maturation of the SI epithelium 3 d after administration – that is after exchange of the intestinal epithelium ( 5 , 11 , 13 , 15 ) . The experiments were performed in a split-litter manner that included one of the treatments and controls at two different time points per litter (three to four rat pups×2 litters/group) (Fig.…”

Telocytes role during the postnatal development of the Mongolian gerbil jejunum

“…At birth, the jejunum, like the rest of the intestine, is not yet fully mature. From birth to weaning, the rat intestine continues to develop, with an increase in proliferative activity, in villi width and in immunological activity (Cummins et al 1988;Montgomery et al, 1999, Sureda et al, 2017. The complete network of cell interactions and molecular pathways related to the jejunum development has not been completely elucidated; thus, the presence of telocytes during intestinal development could indicate a greater complexity to this process.…”

“…Thus, the Mongolian gerbil tends to show a more pronounced postnatal development (Sanches et al, 2014). The weaning period also occurs later, at the end of the first postnatal month (Norris and Adams, 1972), while in the rat, it occurs at the end of the third week (Cummins et al 1988); therefore, the gerbil becomes useful for studies of the development of the intestine, considering that part of the intestinal development occurs during the postnatal period until the onset of weaning (Sureda et al, 2017). The current study aims to evaluate the presence of telocytes in two distinct periods of the postnatal development of the jejunum in the Mongolian gerbil, as well as to investigate a possible implication of these cells in it.…”