background: the nucleus raphe magnus (nrm) is involved in thermoregulatory processing. there is a correlation between changes in the firing rates of the cells in the nrm and the application of the peripheral thermal stimulus. introduction: we examined the effect of reversible inactivation and excitation of nrm on mechanisms involved in tail blood flow (tbf) regulation in hypothermia. methods: h...

Recent studies with cytochrome P450 (P450) enzymes from the 2E and 2B subfamilies have shed light on what may be a new trend in the mechanism-based inactivation of P450s: reversibility. The reversible inactivation of P450-type enzymes was first reported in the mid-1990s by Dexter and Hager [Dexter AF and Hager LP (1995) J Am Chem Soc 117:817-818], who studied the transient heme N-alkylation of ...

Herpes simplex virus (HSV) entry into a subset of cells requires endocytosis and endosomal low pH. Preexposure of isolated virions to mildly acidic pH of 5 to 6 partially inactivates HSV infectivity in an irreversible manner. Acid inactivation is a hallmark of viruses that enter via low-pH pathways; this occurs by pretriggering conformational changes essential for fusion. The target and mechani...

The opponent-process theory posits that the aversive state of acute opiate withdrawal is a consequence of, and depends on, the previous rewarding state evoked by acute morphine reward. Although the brainstem tegmental pedunculopontine nucleus (TPP) is crucial for the rewarding component of morphine, the source of the later aversive component is not known. It is possible that (i) the second aver...

The human arylamine N-acetyltransferases NAT1 and NAT2 are important xenobiotic-metabolizing enzymes involved in the detoxification and metabolic activation of numerous drugs and chemicals. NAT activity depends on genetic polymorphisms and on environmental factors. It has been shown that low NAT-acetylation activity could increase the risk of age-dependent cataract, suggesting that NAT detoxifi...