ABSTRACT
Monitoring the toxicological load applied to inaccessible tissues is overtly challenging. To overcome this challenge, it has been proposed that surrogate tissue analysis (STA) be employed to monitor the health and condition of the inaccessible “target” tissue using markers that are indicative of insult. For example, it has been observed that following exposure to polycyclic hydrocarbons, similar groups of DNA adducts appear in rat peripheral blood leukocytes (PBLs), lungs and liver.1
These modifications are maintained for up to 56 days after exposure. This clearly shows that PBLs can be used as surrogates for assessing the influence of genotoxic agents on remote internal organs or tissues. STAs have also been applied to reproductive tissues. For example, the levels of alpha-4 and beta-3 integrins in PBLs have been used to monitor and correctly predict the receptivity of the uterine
endometrium to embryonic implantation2 (see Chapter 8). In this example, the benefits of using PBLs as a surrogate for endometrial biopsies are evident, as drawing blood is relatively trouble-free, reducing the opportunity for intrauterine infection with little trauma. Although some of the fractions isolated from peripheral blood, e.g., leukocytes, have received the most attention as possible surrogates for tissue analysis, several other candidates including hair and sperm are well suited to this task.
