19-hydroxylation of 18-hydroxy-11-deoxycorticosterone by adrenal mitochondria prepared from various animal species

Abstract

We have recently reported that bovine adrenocortical cytochrome P-450 11β catalyzes 19-hydroxylation of 18-hydroxy-11-deoxycorticosterone (18(OH)DOC) in addition to 11β-hydroxylation of the steroid. In this report, we examine the presence of these two activities in 18(OH)DOC and 11β-and 18-hydroxylation activities on deoxycorticosterone (DOC) among the adrenal mitochondria prepared from man, ox, pig, rabbit, guinea-pig and rat. The results indicate that these animals could be classified into three groups with respect of these hydroxylation activities. Mitochondria of the first group comprising ox and pig showed rather high 19- and 11β -hydroxylation activities on 18(OH)DOC compared to the hydroxylation activities on DOC. Mitochondria prepared from the second group which comprised rabbit, guinea-pig and man showed low 19-hydroxylation activity on 18(OH)DOC, whereas the 11β -hydroxylation of 18(OH)DOC well occurred in these species. The last group comprising rat had very low activity both of 11β- and 19-hydroxylations when 18(OH)DOC was used as the substrate, whereas both 11β- and 18-hydroxylations of DOC were high in rat adrenal mitochondria. No significant difference of these activities could be found between zona glomerulosa cells and zonae fasciculata-reticularis cells of bovine adrenal cortex, and between adrenal mitochondria from spontaneously hypertensive rat and those from WKY normotensive rat.