Perinatal Development of the Small Intestine and Pancreas in Rat and Spiny Mouse

Abstract

Rat (Raitus norvegicus)and spiny mouse (Acomys cahirinus)are closely related species that mainly differ in the developmental timing of birth. A comparison between the developmental profiles of some characteristic enzymes of the small intestine (lactase and sucrase) and of the pancreas (amylase) of both species was carried out to elucidate the question to what extent these enzymic profiles and hence the maturation of these organs was related to the process of birth. It was found that these organ-specific enzymes become first detectable at the same developmental stage in both species. Likewise, the weaning phase of the enzymic profiles occurred at the same developmental time point in both species. It is argued that both the first appearance and the weaning increase in enzyme activity follow an inherent biological program that can only be modulated by hormones. In contrast, the perinatal phase of the enzymic profile is completely dependent on the developmental timing of birth, and therefore appears not to be anchored to a particular developmental time point but rather to be dependent on birth-associated (hormonal) adaptation. In accordance with this hypothesis it was found that the development of the microscopic anatomy of the small intestine proceeded independently of the functional adaptation of the intestine to the process of birth.

Changes in Upper Intestinal Epithelial Morphology and Kinetics in the Growing Guinea Pig

“…These findings are in keeping with the hypothesis that birth is a "movable" event which occurs at different time points in the course of the ontogeny of the gut in different mammals (1,26). In altricial species, such as the rat and mouse, birth occurs comparatively early in gut ontogeny, and weaning represents a major event in gastrointestinal maturation.…”

Development of complementary expression patterns of E‐ and N‐cadherin in the mouse liver

“…[19][20][21][22][23]30 Periportal and perivenous hepatocytes show differences in terms of the activities of a number of enzymes. 22,[31][32][33] However, all hepatocytes of the newborn mouse have similar amounts of typical periportal enzymes such as succinate dehydrogenase, 31 glucose-6-phosphatase [34][35][36] and phosphoenolpyruvate carboxykinase. 31,36,37 Heterogeneity in the activity of these enzymes depends on their localization in the liver lobule and gradually develops during the first 10 days of postnatal development.…”

The Prenatal Development and Glucocorticoid Control of Brush-Border Hydrolases in the Pig Small Intestine

“…In mammals, the activity of lactase increases rapidly in the late fetal period and peaks at or soon after birth, and the similarities between altricial species (e.g. rat, rabbit) and precocious species (pig, guinea pig, and human) have previously led to the suggestion that the timing of certain enzymatic changes is in some way related to the process of birth (4,26). The present results indicate that the prepartum rise in circulating cortisol stimulates increases in lactase-phlorizin hydrolase, maltase-glucoamylase, aminopeptidase N, and aminopeptidase A activity in the fetal pig intestine.…”