The highly polymorphic human PON1 gene has approximately 200 polymorphisms identified to date. The C-108T polymorphism influences PON1 levels with the C-108 allele producing on average approximately 2 x more PON1 than T-108. The Q 192R coding region polymorphism affects the catalytic efficiency of hydrolysis of some but not all PON1 substrates. Individual plasma PON1 levels vary 13-fold in adults. Newborns have approximately 3-4-fold lower PON1 levels than adults. PON1-1- mice have approximately ", 10-fold greater sensitivity to diazoxon (DZO) and chorpyrifos oxon (CPO). Injecting purified human PON1-Q or RI92 restores resistance, with either alloform protecting equivalently against DZO exposure and PON1192 providing greater protection against CPO exposure. Toxicity studies in mice expressing human hPON1Q192 or hPON1R192 confirm the latter observation. This observation is of concern, since PON1Q192 homozygotes comprise up to 50% of most populations. PON1 status is determined with a 2-substrate assay/analysis where rates of DZO hydrolysis are plotted against rates, of paraoxon hydrolysis, clearly separating the three PON1192 functional phenotypes (QQ/QR/RR) and at the same lime providing measurement of plasma PON1 levels, both of which arc important in determining resistance to CPO exposures und required doses for drugs activated or inactivated by PON1.
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.