Metabolism of Retinal Blood Vessels of Humans and Rhesus Monkeys Studied with the Cartesian Diver

¹ Department of Surgery, Yale University School of Medicine, New Haven, Conn.

Metabolic data for normal adult rhesus monkey and human adult retinal vessels are presented for the first time. The Cartesian diver microrespirometer was employed to measure respiration and respiratory quotients. Human retinal arterioles consume oxygen at the rate of 0.5 to 28 µl of oxygen per milligram of dry tissue per hour while the venules consume oxygen in the range of 1 to 27 µl of oxygen per milligram of dry tissue per hour. Normal adult rhesus monkey arterioles have a QO₂ of 3 to 20, and the venules a QO₂ of 2 to 27. The variation of QO₂ is interpreted to refect a change of respiration rate with vessel diameter, with the smaller diameter arterioles and venules consuming oxygen at a higher rate than the larger diameter vessels. Respiratory quotient data suggest a mixed, substrate utilization.