Clinical pathology in the female rat during the pre- and postnatal period

Time-course changes of hematology and clinical chemistry values in pregnant rats

“…RBC, Hb and Ht decreased on Days 7, 14, 17 and 21 compared with non-pregnant rats, and the degree of decrease correlated with the course of pregnancy. These changes were consistent with the results of previous studies on pregnant rats (LaBorde et al, 1999;Papworth and Clubb, 1995;De Rijk et al, 2002;Kim et al, 2000;Katoh et al, 1992), rabbits (Wells et al, 1999), and womanemia, can be attributed to the normal plasma volume increase termed as hemodilution that occurs during pregnancy (Papworth and Clubb, 1995;De Rijk et al, 2002;Kim et al, 2000;Katoh et al, 1992;Baylis, 1980) and Table 1 to a decrease in the lifespan of erythrocytes (Lurie and Danon, 1992). Reticulocyte increased on Days 7, 14 and 17; this change might be a compensatory response to anemia; however, it was on the same level as that of non-pregnant -ciency anemia was induced in pregnant rats at the end of pregnancy, similar to pregnant women (Haram et al, 2001).…”

“…observed on Days 17 and 21 are essentially similar to that reported by Papworth and Clubb (1995). The change in APTT could be a mechanism to prevent the development of deep tissue thrombosis in dams during the gesprolonged bleeding at parturition.…”

Hematology and clinical chemistry values in pregnant Wistar Hannover rats compared with nonmated controls

“…Slightly higher MCHC results in pregnant versus nonmated rats in this study were similar to results reported for pregnant women 13 but differed from results reported for Sprague‐Dawley rats 8,9,11 . Higher RTIC (% and CT) and PLT values were consistent with those reported for Sprague‐Dawley rats 9–11 . Decreased RTIC and PLT values were reported in pregnant rabbits near term 12 .…”

“…The days selected in this study for blood collection (GD 18/19) were 1 day following the completion of test article administration (GD 17) and prior to the scheduled day of cesarean section and/or euthanasia (GD 20 or GD 21), increasing the likelihood of detecting subtle changes due to the test article. Other investigators have sampled on GD 20, the day of cesarean section, 7 or have obtained serial samples over a range of days 8,9 . The day selected is less important than consistency in the day or days of blood collection for comparing pregnant and non‐mated animals.…”

Lactation modifies stress-induced immune changes in laboratory rats

“…It has been hypothesized in eco-immunological literature that a trade-off may exist between reproduction and immune activity (reviewed in Harshman and Zera, 2007). According to this concept, particularly during the energy demanding process of lactation (Hansen and Ferreira, 1986;Papworth and Clubb, 1995), a reallocation of resources from the immune system may be required to meet the costs of lactation (Coop and Kyriazakis, 1999;Demas et al, 1997;Jäckel, 2003). One problem with this concept is that maintenance of activity levels of resting immune cells does not consume much energy (Krauss et al, 2001;Maciver et al, 2008).…”