Glutamine digestion

The two important fuels for colonocytes are glutamine and short-chain fatty acids. The oxidation of both fuels provides ATP for the cells, which is important not only to maintain digestive and absorptive functions but also to maintain membrane structure and hence the physical barrier between the lumen and the blood and peritoneal cavity. This barrier normally prevents significant rates of translocation of bacteria into the peritoneal cavity and thence into the blood. If this barrier is breached, translocation of pathogens and... 

Although glutamine is present in protein and therefore made available in the lumen of the intestine by digestion, most of this is metabolised after absorption by the enterocytes in the intestine. Glutamine, therefore, has to be synthesised in the body, the precursors for which are glucose and branched-chain amino acids. It is synthesised in muscle, adipose tissue and the lung (see Figure 8.23). Furthermore, muscle... 

Ficus carica L. Wu Hua Go (Fig) (leaf, fruit) Bergaptin, cerotinic acid, ficusin, glutamine, papain, pepsin, psoralen, guaiaxulene, amyrin, lupeol, retin, octacosane, guaiacol, quercitin, rhamnose, sitosterol, tyrosine, urease.50 55,502 For stomachache, externally for swollen piles, corns, warts. Fruit is laxative, digestive, anthelmintic, hypolipidaemic, and hypotriglyceridaemic acitivities... 

This metabolic activity is achieved by a turnover of amino acids and proteins that is as rapid as that of lipids and carbohydrates. In an adult human male, 400 g of body proteins is turned over each day. Of this, 50g is used to replace digestive enzymes (Sec. 15.2), and 6g to replace hemoglobin (Sec. 15.8). The concentration of free amino acids in plasma is small (total 3.2mmol L l, of which 25 percent is glutamine), but the turnover of 400g per day of protein is equivalent to the uptake, and release back into the plasma, of 4.6 moles of a-amino-N, so that the average lifetime of an amino... 

Figure 9-1 The highlights of the chick embryonic neural retina micromass cultures are depicted. The tissue is harvested and digested to a single-cell suspension. These are placed into culture, and after 24 h three parameters are measured (a) the number of aggregates that are produced, (b) the size of the aggregates, and (c) their protein content. After five days cortisol is added to precociously induce glutamine synthetase activity. This is measured two days later, after a total of seven days of culture. Each parameter is uniquely sensitive to different agents, but a decrease in any one parameter is considered to be toxicologically relevant.

---