Receptors reactivation

Bras R, Szkilnik R, Popieluch I, et al. 1997b. Effect of aluminum exposure on central serotonin and muscarine receptor reactivity in rats. Med Sci Monit 3 631-636. 

Existing treatment protocols emphasize three complementary approaches antagonize the muscarinic ACh receptor, reactivate endogenous AChE with oxime therapy, and manage the severe toxicity symptomatically (Lee, 2003). Atropine is the dmg of choice for mitigating the synaptic ACh accumulation, and is titrated until the patient... 

This question has been answered by RRA and RIA studies showing profound fidls in somatomedin peptides in malnourished rats and humans. Tak-ano et al. (T2) reported that, in sting rats, an 80% loss of receptor-reactive somatomedin-A occurred within the first 24 hours. Similar decreases have been seen using SM-C/IGF-I RRA or RIA methods on extracted or unextracted serum samples, in fiisted adult rats (B16, M2), or chronically mal-... 

Fig. 15. Scheme of drug (i4)-receptor R) interaction, receptor activation (il ), substrate (S) binding, product (P) formation, receptor inactivation (H ) and receptor reactivation R — R). , d), — individual reaction steps. All steps are reversible the solid apices of the arrows show the predominant direction of the reactions. 

Toxic reactions occur by several mechanisms activation of metabolism, production of reactive intermediates and subsequent reactions with cell macromolecules, changing receptor responses, or through abnormal defence reactions. Several compounds cause toxicity by mimicking the organism s own hormones or neurotransmitters, or activating the body s endogenous receptors in some non-physiological way. ... 

These small-molecule thiols serve to transfer NO from erythrocytes to endothelial receptors, where it acts to relax vascular tension. NO itself is a reactive free-radical compound whose biological half-life is very short (1-5 sec). S-nitrosoglutathione has a half-life of several hours. 

The involvement of serotonin (5-hydroxytryptamine) in disease states has been recognized for several decades. Research on antagonists awaited the recent development of methodology involving serotonin receptors. A thiazolopyrimidone serves as the nucleus for a pair of serotonin antagonists. The key intermediate 118 is in fact simply the lactonized form of 2-hydroxyethyl acetoace-tate. Condensation of this P-keto ester can be visualized to involve initial attack on the reactive... 

In the interstitium, angiotensin II induces proliferation of mesangial cells and fibroblasts and the synthesis of collagen and other matrix molecules by these cells via the ATI receptor. Moreover, by the concomitant stimulation of chemoattractant cytokines, inflammation is induced. These processes are mediated by endothelin, transforming growth factor(3, and reactive oxygen species, and finally lead to interstitial fibrosis and glomerulosclerosis observed in hypertension and diabetes. 

---