In contrast, metabolic
acid load in growing swine can also alter Cl retention (Budde
and Crenshaw, 2003), while not affecting the urinary excretion
of Cl. The losses of Cl in urine observed in the present
study but not in the study by Budde and Crenshaw (2003)
may indicate an adaptive renal response to benzoic acid. More
specifically, the influence of enhanced H+ that is derived from
benzoic acid may directly alter the renal compensatory
mechanism driven towards maintenance of plasma pH.
Given that bone weight and Ca concentration in bone ash
were affected by benzoic acid, a change in bone resorption
induced to buffer the increase in acid absorption is likely. If
one considers that the normal resorption of AA from the
glomerular filtrate is associated with cotransport of Na, a
conjugation of free glycine with benzoic acid may have
indirectly increased Na excretion in urine of the pigs fed the
benzoic acid-containing diets.