Determination of mean whole body intracellular pH  in unanesthetized dogs.
In order to determine mean whole body pHi in unanesthetized dogs, assumptions on the urinary and intestinal excretion of DMO, the total loss of an injected single dose of [14C] DMO, and the distribution kinetics of DMO were tested experimentally. Urinary excretion of DMO was almost negligible. The best assumption on the total loss of DMO was based on the exponential decay observed over a period of 1 to 4 weeks. The biological half-life of DMO was 5 days, the time constant being --0.14 d-1. The extracellular distribution of DMO was considered to equal that of [3H] inulin. Between 1 and 7 hours after an injection of inulin in nephrectomized dogs the distribution volume increased linearly from 16% of the body weight after 2 hours to 21% after 6 hours. Based on these experimental results, pHi was determined in 16 unanesthetized dogs. 120 min after the injection of DMO pHi was 7.05 and 430 min after the injection pHi was 7.11. It is concluded that the assumption made allow the estimation of pHi in unanesthetized dogs over a period of 1 to 7 hours.
D000136:Acid-Base Equilibrium; D000818:Animals; D001769:Blood; D001826:Body Fluids; D001831:Body Temperature; D002245:Carbon Dioxide / Q000097:blood; D004114:Dimethadione / Q000032:analysis / Q000097:blood / Q000652:urine; D004285:Dogs; D005110:Extracellular Space / Q000032:analysis; D005243:Feces / Q000032:analysis; D006207:Half-Life; D006454:Hemoglobins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007424:Intracellular Fluid / Q000032:analysis; D007444:Inulin; D007700:Kinetics; D008433:Mathematics; D009392:Nephrectomy; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D013997:Time Factors
D006454:Hemoglobins; D002245:Carbon Dioxide; D007444:Inulin; D004114:Dimethadione; D010100:Oxygen