[The acid-base status of the blood of normal subjects with different ABO blood group systems in different seasons of the year].

A total of 180 normal subjects with all AB0 blood groups, aged 18 to 50, were examined with the use of Astrup's micromethod in various seasons--in spring, summer, fall, and winter. The blood was found more acid in summer than in the fall and more alkaline in spring than in winter. Hypocapnia was detected in all the examinees over the year.