Abstract
Bilirubin glucuronyl transferase activity (BGT) is negligible in jaundiced (jj) Gunn rats, with intermediate and higher levels in heterozygous (Jj) and outbred (JJ) rats, respectively. This could be explained either by a defective enzyme or structural defects in the endoplasmic reticulum in which the enzyme is compartmented. If the latter interpretation is correct, similarly segregating activities might be expected among other microsomal enzymes. The activity of aminopyrine demethylase (AD), a hepatic microsomal mixed-function oxidase, was assayed in male jj, Jj, JJ Gunn and Wistar (Wi) rats. BGT (μg bilirubin conjugated/30 min/mg protein N) and AD (nmoles CH2O produced/min/mg protein) are shown below (mean±SD). Results: jj AD < Jj, JJ or Wi AD (p < .05). F-test demonstrated AD variance in Jj > jj or JJ rats (p < .05). A correlation (r=.81) exists between BGT and AD (p < .01) in JJ rats, but not in Jj rats. The data suggests a microsomal membrane defect in enzyme compartmentation may be the primary abnormality in the Gunn rat and possibly in Crigler-Najjar Syndrome.
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Gourley, G., Mogilevsky, W. & Odell, G. 719 AN ALTERNATIVE INTERPRETATION OF THE ENZYME DEFICIENCY IN THE GUNN RAT. Pediatr Res 15 (Suppl 4), 562 (1981). https://doi.org/10.1203/00006450-198104001-00742
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DOI: https://doi.org/10.1203/00006450-198104001-00742