Distribution of Glutamate Ammoniagenesis in Rat Kidneys

Abstract

To determine the areas of rat kidney which increase ammoniagenesis in response to acid challenge, ammonia production was followed in vitro in slices from the cortex, outer stripe of outer medulla, inner stripe of the outer medulla, and inner medulla (papilla). When the medium pH was lowered to pH 7.0, increased production of ammonia occurred only in the cortical tissue. When kidney slices were removed from chronically acidotic rats, ammonia production from glutamate increased in the cortex, and outer and inner stripe of the outer medulla. Despite small increases in ammonia production from glutamate in the outer medulla of chronically acidotic rats, it is concluded that the major adaptive increases in ammoniagenesis in response to acid challenge take place in the renal cortex.

The Renal Excretion of Hydrogen Ions in Infants and Children

“…No data are known about the distal tubular volume. Presumably the proximal and distal con voluted tubules are responsible for ammonia production [4,11]. Secondly, the gluconeogenic capacity of the renal cortex of the younger child may be rate-limiting.…”