A. Mahl et al., Comparison of clinical pathology parameters with two different blood sampling techniques in rats: retrobulbar plexus versus sublingual vein, LAB ANIMALS, 34(4), 2000, pp. 351-361
Blood samples were taken from the retrobulbar venous plexus or the sublingu
al vein of male HanIbm:Wist rats to compare clinical pathology parameters b
etween the two sampling techniques. By analogy with a pharmacokinetic study
, blood was sampled six times during one day from unfasted animals. After 3
weeks of:recovery, blood was taken from fasted animals on a single occasio
n. In addition, prolactin and corticosterone levels were determined to comp
are stress-related effects between the two sampling methods. Body weight de
velopment and food consumption were similar after single as well as after r
epeated blood sampling for the two blood sampling techniques. Haemotologica
l evaluation showed a gradual decrease in erythrocyte count, haemoglobin co
ncentration and haematocrit after repeated blood sampling. Repeated withdra
wal of blood samples over 24 h corresponding to approximately 22% of the to
tal blood volume resulted in a decrease in red blood cell parameters by up
to 30%. The withdrawal of approximately 10% of the total blood volume was a
ssociated with a decrease in these parameters by up to 10% and should not b
e exceeded for animal welfare reasons and to allow a reliable evaluation of
data in a study. Repeated blood sampling was associated with an initial de
crease in the number of white blood cells, mainly due to a reduction in lym
phocytes; white blood cell counts were slightly increased one day after. Th
e decrease in lymphocytes and the increase in neutrophils after repeated sa
mpling were generally slightly more pronounced in the blood from the retrob
ulbar plexus than from the sublingual vein. Comparison of serum clinical ch
emistry data showed significantly higher activities of creatine kinase and
aspartate aminotransferase in samples from the retrobulbar plexus. These fi
ndings suggest a higher degree of tissue damage with blood sampling from th
e retrobulbar plexus than from the sublingual vein. Despite a large inter-i
ndividual variability higher mean values of prolactin on each occasion and
corticosterone after a single sample in fasted animals indicate a higher st
ress associated with blood sampling from the retrobulbar plexus.