Kinetics of Plasma Hemoglobin Catabolism in the Rat. I. Blood Clearance of I131 Tagged Hemoglobin.

Inducible heme oxygenase in the kidney: a model for the homeostatic control of hemoglobin catabolism

“…Control animals received an intravenous injection of isotonic saline. In most experiments, 30 mg of hemoglobin per 100 g body weight was given; this dose exceeded by far the haptoglobin-binding capacity of the plasma (10), regularly led to hemoglobinuria and generally resulted in maximal stimulation of renal heme oxygenase activity. In the dose-effect studies, 5-50 mg of hemoglobin was injected per 100 g body weight.…”

“…Radioactivity excreted in the urine was compared with the excreted amount of hemoglobin, determined colorimetrically. Nine rats were depleted of their plasma haptoglobin (10,11) by two preliminary intravenous injections of 10 mg native hemoglobin spaced 1 hr apart. 1 hr later, each animal received intravenously, 2 mg of BME-treated or 2…”

“…As the kidney normally is not involved in the breakdown of red cells or hemoglobin, it expectedly has very low levels of heme oxygenase activity (5). However, in severe intravascular hemolysis, when hemoglobin released from circulating red cells exceeds the binding capacity of the plasma haptoglobin (10), unbound hemoglobin may be filtered by the renal glomeruli and appear in the urine (11). From the study of Bunn and Jandl (12), it would appear that in hemoglobinemia with hemoglobinuria, the kidney may be able to catabolize part of the filtered hemoglobin that has been reabsorbed by proximal convoluted tubules (13)(14)(15)(16).…”

Haptoglobins In Some Galliformes Birds

“…In birds, the clearance rate of Hb-59 Fe is exponential as has been observed in rabbits (Murray et al, 1961) and in rats (Franklin et al, I960;Gabrielli et al, 1962Gabrielli et al, , 1963. The existence of two different rates could be explained by the elimination of free Hb and Hb-Hp complex, using first order and zero order kinetics, respectively.…”

“…is inversely proportional to the dose administered; varying between 100 and 264 minutes. The comparative data in the literature referred to free Hb and Hb-Hp complex are: for man, 207 and 250 minutes (Lathem and Worley, 1959); for rabbits, 25 and 80-100 minutes (Murray et al, 1961;Franklin et al, I960;Engler et al, 1966); for rats, 30 and 120 minutes (Franklin et al, I960;Gabrielli et al, 1962;Krauss and Sarcione, 1966).…”