Da. Cave et al., CONTINUOUS INTRAVENOUS-INFUSION IN THE UNRESTRAINED RAT - PROCEDURES AND RESULTS, Human & experimental toxicology, 14(2), 1995, pp. 192-200
1 A method of continuous infusion in the unrestrained rat is described
, which provides a scientifically acceptable and easily maintained rod
ent model for use in toxicological investigations. 2 Sprague Dawley SP
F rats had cannulas implanted into the vena cava via the femoral vein,
and were continuously infused with physiological saline for a total o
f 28 or 90 days. 3 The results indicate that there was no change in bo
dy weight, food consumption, clinical observations or clinical biochem
istry of infused rats when compared to non-infused rats. There were sm
all changes in haematological parameters, however none were toxicologi
cally significant. Urinary volume was increased and urinary specific g
ravity and osmolality were decreased. At macroscopic and microscopic e
xamination there were findings of scar formation associated with the a
rea of surgery and minimal irritation in the area of the vena cava whi
ch accommodated the cannula. 4 These results indicate that implantatio
n of a cannula into the vena cava of a rat and subsequent continuous i
ntravenous infusion of physiological saline produces no toxicological
adverse effects over a period of 90 days. Consequently, this model can
be recommended for the continuous intravenous administration of test
substances to rats.