Some problems in the use of antipyrine andN-acetyl-4-aminoantipyrine in the determination of body water in cattle

Abstract

An accurate in vivo estimation of the body water of animals would be of great value in many nutritional and physiological studies. In the ruminants a method for the separate measurement of body water of the tissues, tissue spaces and circulatory systems (empty body) and of the water of the gastro-intestinal tract (gut water) would be of additional value. One of the most promising methods for determining body water indirectly is the injection into the blood stream of a non-toxic compound that evenly and rapidly distributes itself throughout all body water, that is transformed in or excreted from all body tissues slowly and uniformly, and that can be conveniently and accurately estimated in blood plasma or other body tissues. Soberman, Brodie, Levy, Axelrod, Hollander & Steele (1949) proposed the use of antipyrine (AP) as such a compound for measuring body water indirectly in man and dogs, and later Brodie, Berger, Axelrod, Dunning, Porosowska & Steele ( 1 9 5 1 )proposed the use of N-acetyl-4-aminoantipyrine (NAAP), as this latter compound did not bind with plasma proteins to the same extent as AP. Kraybill, Hankins & Bitter (195 I ) adapted the AP method for use with cattle and found in a study with thirty animals of varying degrees of fatness that the value for body fat, calculated from body water determined by AP, agreed well with that calculated from specific-gravity measurements. Wellington, Reid, Bratzler & Miller (1956) reported that in twenty cattle determinations of body water by the AP technique and by toluene distillation of the body tissues after slaughter agreed closely.On the other hand, White & MacDonald (1956), using cattle, and MacFarlane, Morris & Howard (1956), using sheep, reported unpredictable occurrences of impossible values when AP was used to measure body water. MacFadden & Richards (1956) and Swanson & Neathery (1956) found that the length of time that feed and water were withheld before the injection of AP had a significant effect on the estimated amount of body water. Garrett, Meyer & Lofgreen (1959) in an experiment with thirty-six steers did not find a significant correlation between body fat determined by the use of AP and that determined by specific-gravity measurements of the ninthtenth-eleventh rib sections. In trials with sheep these authors reported also that the length of time feed and water were withheld before the injection of AP had a marked effect on the estimated body water. Rumen samples from these sheep showed that * Research Branch, Canada Department of Agriculture, on postgraduate transfer of work. the concentration of AP in the rumen water varied between 75 and 162% of the concentration in the serum water at the same time.Reid, Balch, Head & Stroud (1957), in a study to compare the use of AP and NAAP for estimating body water in cattle, noted that these compounds were not found in the reticulo-ruminal water in the same concentration as in the blood water. The diffusion of AP into the reticulo-rumen was much more rapid than that of NAAP. This observation led the aut...