Blood Gases Tensions and Acid CLD Base Imbalance of Cayman Latirostris Submitted to APNEA and Pure Oxygen Breathing

This work intended to test the broad nosed caiman (Cayman latirostris, Daudin, 1802) pattern of acid base imbalance during aero¬bic apnea from six broad nosed caiman with different sizes. Animals were kept under forced apnea and blood was collected before and during the apnea. Thus, animals were ventilated with pure oxygen. Blood collects were done also during the onset of oxygen¬ation. We evaluated pH, pCO2, pO2, tem-perature, and heart rate. As expected, in our study, pO2 fell and pCO2 levels rose during forced apnea. Apneaʹs bicarbonate and Ph mean values started at 15.7 mmol.l-1 and 7.09, respectively, until an end-apnea value of 14.3 mmol.l-1 and 6.99, respectively. However, between 15 and 20 minutes and at 15 minutes of apnea, there was a small rise in bicarbonate and pH levels, respectively. Crocodilians in our study had bradycardia that could be associated to the smaller fall of pO2 levels between 15 and 20 minutes of apnea. A significant dependence on body weight just in end-apnea pCO2 and pO2 levels was seen. After lactic acidosis, bicar¬bonate decreased significantly according to body mass. This could corroborate that CO2 body storage is effective in blood pCO2 con¬trol during prolonged aerobic apnea, helping to control pH and lung oxygen uptake.