Metabolic pathways short-term

Both interindividual variations (responders and non-responders) and variable intraindividual temporal efficacy (short-term responders) for HbF expression may reflect the inherited differences in the metabolic pathways of the drug, in their targets, or in their adaptative mechanisms. These aspects remain to be clarified. 

Figure 5-5. Metabolic activities of major organs during a short-term fast. The importance of the liver in providing glucose to support the brain and other glucose-requiring organs in the post-absorptive state is illustrated. The body relies on available glycogen stores as a ready source for glucose as fuel. PPP, pentose phosphate pathway FA, fatty adds TAG, triacylglycerol.

The short-term metabolism of metribuzin may involve two major nonconjugative pathways, two major conjugative pathways, and/or production of nonextractable residues. 

All of the above discussion on the functional properties of metabolic pathways has focused on short-term responses. The question arises of the effects of adjustments over acclimation or intermediate time courses because studies with humans and mammals dominate this field, we will refer to these as training effects rather than acclimations (the term that is used elsewhere throughout this book). 

Hemeproteins are widespread in all groups of living organisms, both as components of key biological processes as well as in very specific metabolic pathways. By variation of either the heme porphyrin structure or the heme protein environment, the function and behavior of the hemeproteins may vary drastically, allowing its role in the most diverse processes. In this short review, selected examples of hemeproteins from anaerobes will be presented, aiming to show the basic, common features of these family of proteins, as well as their diversity in terms of function and composition. 

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