Oxygen delivery and uptake in dogs during anemic and hypoxic hypoxia.

Three groups of dogs were anesthetized, paralyzed, and ventilated at constant rates with the spleen clamped. Two groups were isovolemically hemodiluted with warm dextran and plasma to hematocrits just above and below that at which O2 uptake (VO2) could not be maintained at preanemic levels. One of these groups was given propranolol to reduce the cardiac output response to anemia.

Arterial lactate responses in dogs made apneic or breathing nitrogen.

O2 stores are kept more intact in apnea than in N2 breathing which removes O2stores from the body. If lactate moves readily into the circulation, arterial lactate should rise sooner with N2 breathing than with apnea because tissue O2 is lowered faster. This was tested in 10 anesthetized, paralyzed dogs made hypoxic both ways.

pH effects on lactate and excess lactate in relation to O2 deficit in hypoxic dogs.

Both hypoxemia and alkalemia increase arterial lactate levels, but excess lactate (XL) may be better related to the true O2 deficit and less subject to the pH effect upon glycolysis. To test this idea, 50 anesthetized (30 ml/kg pentobarbital sodium) and paralyzed dogs in five groups were ventilated with low O2 mixtures. Arterial pH was altered by CO2, hyperventilation, and HCO3- so that the average pH of the five groups were 6.

Tissue oxygenation and splenic erythropoiesis during chronic hypoxia and hypercapnia.

Tissue (gas pocket) oxygen levels and erythropoietic activity were monitored in groups of rats chronically exposed to hypoxia (70 Torr PIO2), hypercapnia (60 Torr PICO2), or a combination of the two conditions. Arterial gas tensions and pH were also measured. Overall condition of the animals was assessed by comparison of growth rates with pair-fed controls.

Oxygen delivery and utilization in dogs with a sublethal dose of cobalt chloride.

Four groups of eight dogs each were anesthetized with pentobarbital, paralyzed with succinylcholine, and ventilated at constant rate. Control measurements were made for 30 min, then 15 mg/kg of cobaltous chloride was given slowly intravenously to one group. A second group was also given 1 mg/kg per h propranolol (beta-block); a third group was given NaHCO3 to correct pH changes after CoCl2; and a fourth group had both beta-block and NaHCO3.