Our body is able to make use of the metabolic sources in the environment by way of the alimentary tract. In order for it to serve as a conduit for the food and other essential substances, it has to undergo specific functions such as food propulsion, secretion of digestive juices, and absorption of simplified nutrients and vitamins, among others. Needless to say, any interruptions in the continu...

Favorable growth responses have recently been obtained with some phosphorus compounds applied as foliar sprays to vegetable crops, the objective being to supplement the usual supply of phosphorus absorbed by the roots (3). Preliminary studies utilizing a 25 millimolar solution of phosphoric acid enriched with small quantities of radioactive phosphorus indicated that the nutrient was absorbed by...

Chronic energy restriction (ER) dramatically enhances intestinal absorption of nutrients by aged mice. Do adaptations in nutrient absorption develop only after extended ER or immediately after its initiation? To determine the time course of adaptations, we measured rates of intestinal glucose, fructose and proline transport 1-270 d after initiation of ER (70% of ad libitum) in 3-mo old mice. Mi...

Hagfish feed by immersing themselves in the body cavities of decaying animals. This ensures a rich nutrient source for absorption via the gills, skin, and gut, but it may also subject hagfish to reduced levels of dissolved oxygen and elevated levels of the products of biological degradation. This study investigated the impacts of hypoxia and ammonia on the assimilation and metabolism of selecte...

1 Nutrient-rich foods must be available to the family. Sufficient nutrient-rich foods must be available where the family can buy them, and must be affordable. 2 Children must consume enough nutrient-rich foods. Children must be given enough nutrient-rich food to eat. Food must be prepared in such a way that the nutrients are preserved and easily absorbed. For most foods, this means not overcook...

The vertebrate gastrointestinal tract is populated by bacteria and, in some species, protozoa and fungi that can convert dietary and endogenous substrates into absorbable nutrients. Because of a neutral pH and longer digesta retention time, the largest bacterial populations are found in the hindgut or large intestine of mammals, birds, reptiles, and adult amphibians and in the foregut of a few ...

The intestinal absorption of many nutrients and drug molecules is mediated by ion-driven transport mechanisms in the intestinal enterocyte plasma membrane. Clearly, the establishment and maintenance of the driving forces - transepithelial ion gradients - are vital for maximum nutrient absorption. The purpose of this study was to determine the nature of intracellular pH (pH(i)) regulation in res...

The brush-border membrane (BBM) of enterocytes is responsible for the digestion and absorption of nutrients and ions in the small intestine. To identify the BBM proteins involved in epithelial cell maturation along the crypt-villus axis, enterocytes were sequentially isolated from the villus tip to the crypt of the jejunum from 21-day-old suckling piglets. After preparation of BBM vesicles, we ...

Our body is able to make use of the metabolic sources in the environment by way of the alimentary tract. In order for it to serve as a conduit for the food and other essential substances, it has to undergo specific functions such as food propulsion, secretion of digestive juices, and absorption of simplified nutrients and vitamins, among others. Needless to say, any interruptions in the continu...

The soil supports plants, is the physical determinant of root growth and extent, and is the main reservoir for plant-available water and nutrients. Therefore, the soil controls the availability of most essential plant nutrients. It regulates availability by means of biophysiochemical processes, which are functions of soil and plant properties. This chapter introduces the concept of soil nutrien...