Ga. Roland et Gp. Birrenkott, THE EFFECT OF IN-VITRO HEAT-STRESS ON THE UPTAKE OF NEUTRAL RED BY CHICKEN THROMBOCYTES, Poultry science, 77(11), 1998, pp. 1661-1664
Thrombocytes are multifunctional nucleated blood cells. Morphological
changes in thrombocytes have been used as a physiological indicator of
a stress response. This study investigated the effects of in vitro he
at stress (HS) on the neutral red uptake activity of chicken thrombocy
tes. Chicken thrombocytes (98% pure) were prepared from adult Barred P
lymouth Rack and Rhode Island Red males. The isolated thrombocytes wer
e preincubated at normal (41 C) or HS (45 C) temperatures for 30 min b
efore either a 30- or 90-min incubation with neutral red at these same
temperatures. After incubation the cells were washed, lysed, and the
internal neutral red concentrations analyzed. There was no difference
in thrombocyte numbers or their uptake of neutral red in samples from
males of these two chicken breeds. At 41 C thrombocytes actively took
up neutral red over the 90-min incubation period. However, at 45 C thr
ombocyte internalization of neutral red was significantly reduced. At
both time periods (30 and 90 min), thrombocytes at 41 C took up signif
icantly (P less than or equal to 0.05) more neutral red than their cou
nterparts at 45 C. This lack of neutral red uptake was not due to cell
death as monitored by Trypan blue exclusion. Following the 30-min inc
ubation there was no difference in viability between thrombocytes at t
he two temperatures. Although there was a significant (P I 0.05) incre
ase in cell death at 90 min for thrombocytes kept at 45 C, the livabil
ity difference was of a much smaller magnitude than the difference in
neutral red uptake when comparing to cells cultured at 41 C. Neutral r
ed uptake is a rapid, inexpensive and repeatable technique for the stu
dy of thrombocyte function.