PT  - JOURNAL ARTICLE
AU  - Merdink, J
AU  - Decosta, K
AU  - Mathews, J M
AU  - Jones, C B
AU  - Okita, J R
AU  - Okita, R T
TI  - Hydroxylation of lauramide diethanolamine by liver microsomes.
DP  - 1996 Feb 01
TA  - Drug Metabolism and Disposition
PG  - 180--186
VI  - 24
IP  - 2
4099  - http://dmd.aspetjournals.org/content/24/2/180.short
4100  - http://dmd.aspetjournals.org/content/24/2/180.full
SO  - Drug Metab Dispos1996 Feb 01; 24
AB  - Lauramide diethanolamine (LDEA)--a compound used in cosmetics and soap products as an emollient, thickener, and foam stabilizer--was observed to be metabolized by rat liver microsomes to two major products that were identified by GC/MS to be the 11-hydroxy and 12-hydroxy derivatives of LDEA. The specific activities for LDEA 11- and 12-hydroxylation in microsomes prepared from control rats were 2.23 +/- 0.40 and 0.71 +/- 0.17 nmol/min/mg protein, respectively. Treatment of rats with the cytochrome P4504A inducer and peroxisome proliferator, diethylhexyl phthalate, increased the LDEA 12-hydroxylation rate to 3.50 +/- 0.48 nmol/min/mg protein, a 5-fold increase in specific activity, whereas the LDEA 11-hydroxylase activity remained unchanged. Because LDEA contains a 12-carbon side chain, LDEA hydroxylation rates were compared with the hydroxylation rates for lauric acid. The specific activities of lauric acid 11- and 12-hydroxylation reactions in diethylhexyl phthalate-treated rats were 1.7-fold and 3.2-fold greater than the LDEA 11- and 12-hydroxylation rates, respectively. When LDEA hydroxylation reactions were performed in the presence of a polyclonal antibody to the rat P4504A forms, formation of 12-hydroxy-LDEA was inhibited by 80%. Rat kidney microsomes also supported the hydroxylation of LDEA at its 11- and 12-carbon atoms, with specific activities of 0.05 +/- 0.01 and 0.28 +/- 0.02 nmol/min/mg protein, respectively. LDEA was also metabolized to 11- and 12-hydroxy derivatives by human liver microsomes at specific activities of 0.22 +/- 0.06 and 0.84 +/- 0.26 nmol/min/mg protein, respectively.