AHH


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AHH

abbreviation for aryl hydrocarbon hydroxylase.
References in periodicals archive ?
AHH activity was measured in reaction mixtures containing 0.
Figures 1 and 2 show AHH activity for individual animals and the Table shows mean activity [+ or -] SE for each group.
Results were compared using a one-tailed Mann - Whitney U test and showed no significant difference in AHH activity between the different age groups in both males and females of each strain.
This was believed to be biological, and, although the sample sizes used were limited, these initial findings suggest that age is not a major determinant of cutaneous AHH activity.
Mean AHH enzyme activity (SE) in young and old Wistar and Brown Norwegian rats
AHH plays a crucial role in the biotransformation of polycyclic hydrocarbons, the phenolic product of the oxidase reaction being further metabolized by the cytochrome P450-dependent mixed-function oxidase system to highly reactive electrophiles.
In contrast to liver tissue we have shown no change in AHH activity in skin between the ages of 43 and 135 weeks in either strain of rat, in either males or females.
Monocyte AHH is inducible in vitro by polycyclic aromatic hydrocarbons.
This study was designed to examine the association between smoking habits and monocyte AHH activity, and to investigate any possible age-associated difference in enzyme induction.
The data presented here show that whilst AHH activity in monocytes obtained from young and elderly smokers exposed to a comparable number of cigarettes per day is similar, there is no significant difference between smokers and non-smokers, suggesting that in contrast with other tissues, peripheral blood monocytes are not susceptible to this inducing influence.
In vivo induction of AHH by cigarette smoke has been investigated in various human tissues, in particular placenta, where elevated AHH activity in smokers has been widely demonstrated [5, 19].
However, it is known that AHH activity is highly dependent on cytochrome P450 1A1 in placenta [7, 17], whilst cytochrome P450 3A4 seems to be the most likely protein linked to high AHH levels in liver as demonstrated by immuno- and chemical inhibition [21].