[Intensity of acid-base reactions of the blood and cerebrospinal fluid in sheep after intraluminal stress induced by urea and acetic acid].

Acid-base indices of the blood and cerebro-spinal fluid were studied on Astrup apparatus (BMS 2) in an experiment with twelve, two- to three-year-old Merino sheep, being in the first half of the gravidity period, under clinical conditions after the administration of 0.8 g urea per 1 kg live weight followed by, in half an hour, the administration of acetic acid (8% vinegar, a dose of 2 ml per 1 kg live weight). Heparinized syringes were used to take blood samples anaerobically before the beginning of the experiment, then after 15, 30, 45, 60, 75, 90, 105, 120 minutes and after 4 and 24 hours. The fluid was taken by heparinized capillaries before the beginning of the experiment, then after 30, 60, 90 and 120 minutes and after 4 and 24 hours. The following indices were obtained, and/or calculated from nomographs: actual pH, carbon dioxide pressure--pCO2, base excess--BE, buffer bases--BB, standard and actual bicarbonate--SB, AB, total carbon dioxide--tCO2. After 15 minutes' interval since the administration of urea significant changes in the values of the indices, especially higher pH values and paradoxical pCO2 drop, were recorded. After the administration of acetic acid overcompensated acidosis of the organism occurred (accompanied even by mortality of the experimental sheep). Towards the end of the experiments the results illustrated basemia. A depressing effect of the lower pH on the toxicity of ammonia was also confirmed. The reaction of the fluid to the urea and acetic acid stress opposite to the venous blood was retarded and the values of the indices studied showed some variability.