Depletion Patterns of Radioactivity and Tissue Residues in Beef Cattle after the Withdrawal of Oral14C-Diethylstilbestrol

Ts, Rumsey; Rr, Oltjen; Fl, Daniels; As, Kozak

doi:10.2527/jas1975.403539x

Cited by 12 publications

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“…DES in Other Bovine Tissues. Rumsey et al (1975) have shown that in bovines withdrawn from DES treatment, DES decreases rapidly in muscle and serum, less rapidly in feces and urine, and most slowly in bile, kidney, and liver. Our method may be adaptable to measuring DES in these tissues as well as in liver.…”

Section: Resultsmentioning

confidence: 99%

Radioimmunoassay for diethylstilbestrol and the monoglucuronide metabolite in bovine liver

Gridley¹,

Allen²,

Shimoda³

1983

J. Agric. Food Chem.

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The complex matrix in liver causes difficulties in development of a radioimmunoassay (RIA) to quantify compounds bound in liver. An RIA method was developed for diethylstilbestrol (DES) in bovine liver and employs a purification procedure to circumvent these problems; the procedure includes liquid-liquid partitioning, Sephadex LH-20 chromatography, and quantitative enzymatic hydrolysis of the principal metabolite, DES glucuronide. Assay background due to liver matrix was 0.05 ppb (l/109). Average recovery of both DES and its monoglucuronide from fortified liver was 43% by RIA. Tritiated DES used as an internal standard had a higher apparent recovery (67.7%) by liquid scintillation counting. With an in vivo contaminated liver, accuracy was confirmed by a gas chromatography-mass spectrometry method. By repeating the extraction and RIA without enzymatic hydrolysis on this same liver, the free DES was calculated to be 7.8%. The limit of determination for this method with 95% confidence limits is 0.3 ppb.The application of radioimmunoassay (RIA) to drug residue analysis in animal tissues has been limited despite the proven sensitivity and specificity of RIA below the parts per billion (ppb, 1/109) range in biological fluids (Hoffmann, 1978). Complex tissues such as liver necessitate involved purification procedures. Hoffmann (1978) developed such purification procedures with RIA for both natural and synthetic steroids in muscle, liver, kidney, and fat.Diethylstilbestrol (DES) is difficult to quantitate below 1.0 ppb in bovine liver, which is among the last tissues to contain DES after cattle are withdrawn from the drug (Donoho et al., 1973; Aschbacher, 1976). Methods to measure DES in bovine liver include gas chromatography (GC) (Donoho et al., 1973), GC with mass spectrometry (GC-MS) (Day et al., 1975), and liquid chromatography (Kenyhercz and Kissinger, 1978), but quantitation below 1.0 ppb has not been documented for any of these methods.RIA is capable of greater sensitivity.Several researchers have developed RIA techniques for DES (Hoffmann, 1978;Gutierrez-Cernosek and Cernosek, 1977;Richoubac et al., 1977), but none was suitable for use with liver. Hoffmann andLaschutza (1980) and Vogt (1980) developed assays with extensive purification procedures for DES in bovine tissues, including liver; Hoffmann and Laschutza used both silica gel chromatography and liquid-liquid partition while Vogt relied entirely on liquid-liquid partition.In this study, we investigated the use of a simplified purification procedure combined with RIA for detecting and quantifying DES in bovine liver. The method developed was simpler and easier to perform than the above RIA methods. and was previously described (Gutierrez-Cernosek and Cernosek, 1977). The antigenic conjugate was prepared by the method of Rombauts et al. (1973) in which one phenolic group is covalently bonded through an ether linkage to the free amines of bovine serum albumin. The second antibody was lyophilized anti-rabbit y-globulin goat serum obtained from Micromedic ...

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Section: Resultsmentioning

confidence: 99%

Radioimmunoassay for diethylstilbestrol and the monoglucuronide metabolite in bovine liver

Gridley¹,

Allen²,

Shimoda³

1983

J. Agric. Food Chem.

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“…Generalized residue curves for heptachlor epo• (Bovard et al, 1971) and diethylstilbestrol (Rumsey et al, 1975a) that depict lipophilic and hydrophilic residue patterns, respectively. again is based on the heptachlor epoxide data in beef steers of Bovard et al (1971) and represents a lipophilic residue curve; the bottom curve is based on DES in liver of beef steers (Rumsey et al, 1975a) and represents a hydrophilic residue curve. The point to be made by these two generalized curves is the extreme difference in residue load (450 ppb for heptachlor epoxide vs 17 for DES) even though daily intake of DES was approximately 10 times that of heptachlor.…”

Section: Residue Curvementioning

confidence: 99%

“…In terms of the residue curve, figure 8 shows how the use of implants reduces residue load. The generalized curves are based on labeled metabolism studies of Rumsey et al (1975aRumsey et al ( , 1975b and Aschbacher et al (1975). The darker lines project unmeasurable residue at 120 d and show that if DES is fed during a 120-d period (90-d treatment and 30-d withdrawal), residue load before withdrawal in liver tissue is approximately 17 ppb.…”

Section: Residue Curvementioning

confidence: 99%

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Experimental Approaches to Studying Metabolic Fate of Xenobiotics in Food Animals

Rumsey¹

1983

Journal of Animal Science

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The use of agricultural chemicals is an important aspect of animal production. Animal scientists have played an active and varied role in the recent and rapidly developed use of these chemicals. Although approval to use agricultural chemicals has always been based on both efficacy and end point residues, increased consumer concerns during the past one and one-half decades about the safety of these chemicals have caused greater awareness for the latter. In this regard, emphasis on the total residue curve of an agricultural chemical should serve as a tool that will help optimize dose rate on one hand and minimize end point residues on the other hand. Selection against lipophilic materials has resulted in a marked reduction in residue load. However, problems with lipophilic residues still exist, and knowledge about how to prevent or manage these residues in animals as well as fundamental knowledge about their absorption is needed. Continued emphasis on reducing residue load of hydrophilic chemicals through the use of devices such as implants, boluses and ear tags should have high priority as should research on the absorption and excretion mechanisms of these chemicals. There are two important areas of research that are needed to help us deal with end point residues in the future. One is better understanding of the toxicology of end point residues so we can move away from the concept of zero tolerance toward basing all of our guidelines for the use of a chemical on biological principles. The other is better understanding of the specific mode of action of the chemicals we use, which will permit more refined management of agricultural chemicals and a further assurance of safety.

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Metabolism of diethylstilbestrol in the C3H mouse: Chromatographic systems for the quantitative analysis of DES metabolic products

et al. 1978

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Depletion Patterns of Radioactivity and Tissue Residues in Beef Cattle after the Withdrawal of Oral14C-Diethylstilbestrol

Cited by 12 publications

References 0 publications

Radioimmunoassay for diethylstilbestrol and the monoglucuronide metabolite in bovine liver

Radioimmunoassay for diethylstilbestrol and the monoglucuronide metabolite in bovine liver

Experimental Approaches to Studying Metabolic Fate of Xenobiotics in Food Animals

Metabolism of diethylstilbestrol in the C3H mouse: Chromatographic systems for the quantitative analysis of DES metabolic products

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