Ligation of the left aorta in alligators affects acid-base balance: A role for the R → L shunt

This study investigated the effects of preventing bulk flow from the right ventricle to the body via the left aorta (LAo; right to left shunt, R → L) on acid-base status in alligators following feeding, during long-term fasting and a cold temperature exposure. Post-feeding pHv and PvCO2 were not significantly different between S and C. Post-feeding pHv increased in both groups of alligators, but not significantly. During fasting, all acid-base variables were similar between the two groups of alligators. A 10 °C reduction in environmental temperature resulted in a significant difference in pHv and HCO3− between S and C. Both pHv and HCO3− were significantly higher in C animals. PvCO2 significantly decreased in both groups during the cold exposure. Preventing the R → L shunt via the LAo had significant effects on acid-base balance in alligators indicating incomplete compensation for its loss and a role for the LAo in metabolic homeostasis.