Oxidative metabolic capability

Aldrin and dieldrin have similar physical and chemical properties, and hence exhibit similar behavior in animals and during analysis. The following relationship is used as an indicator of oxidative metabolic capability, and it is termed the aldrin metabolic index (AMI) ... 

These studies with aldrin and antipyrine are sufficient to document the in vivo oxidative metabolic capability of mussels. Limits of activity have not been established, but they will be explored by further varying dose and the duration of the test period. With these limits established, the influence of environmental stressors such as salinity, and dissolved and/or suspended particulate matter in water on biotransformation will be assessed. If biotransformation processes are affected by these conditions, their measurement may provide results which can be diagnostically used as indicators of environmental quality. 

These observations suggest that the oxidative reactions occurring on toxaphene are similar in nature to the system described for camphor degradation (M). It is unfortunate that the above experiments could only be conducted with washed intact cells as cell-free preparations in all cases did not exhibit metabolic capabilities. The reason for this phenomenon has not been found, but to our knowledge no other research group has been able to demonstrate pesticide degrading activities of such oxygenase systems in cell-free preparations. 

Figure 7.2 The formation of hippuric acid from benzaldehyde in humans, demonstrating oxidative metabolic capabilities.

A further criterion governing the fate of pyruvate is the type of cell in which it is formed, since some cells (e.g., red blood cells) lack the metabolic capability to carry out the complete oxidation of pyruvate to C02. 

Although other tissues, such as kidney, lungs, adrenal glands, placenta, brain, and skin, have some drug-mctaboliz-ing capability, the biotransfurmutiuns that they carry out often are mure substrate selective and more limited to particular types of reaction (e.g., oxidation, glucuronidation). In many in.stanccs. the full metabolic capabilities of these tis-Mies have not been explored fully. 

The strictly aerobic a-proteobacterium Gluconobacter oxydans is used for a variety of industrial applications for reasons of its unusual metabolic capabilities, in particular, the incomplete oxidation of organic substrates. The main industrial... 

All mammalian cells are virtually capable of producing CO with heme as the main substrate (Fig. 1) [5]. Enzymatic heme metabolism in vivo is mainly catalyzed by heme oxygenase (HO). In the presence of HO, the porphyrin ring of heme is broken and oxidized at the a-methene bridge, producing equimolar amounts of CO, ferrous iron, and biliverdin. Three isoforms of HO have been identified. Inducible HO-1 (32 kDa) is mostly recognized for its upregulation in response... 

---