S. Kondo et al., ACCUMULATION OF VARIOUS N-ACYLETHANOLAMINES INCLUDING N-ARACHIDONOYLETHANOLAMINE (ANANDAMIDE) IN CADMIUM CHLORIDE-ADMINISTERED RAT TESTIS, Archives of biochemistry and biophysics (Print), 354(2), 1998, pp. 303-310
Changes in the levels of various molecular species of N-acylethanolami
ne in CdCl2-administered rat testis were examined. We found that the l
evels of various N-acylethanolamines including anandamide (N-arachido-
noylethanolamine), an endogenous cannabinoid receptor ligand, were dra
matically increased in CdCl2-administered rat testis. Such changes wer
e particularly prominent for saturated and monoenoic species such as N
-palmitoyl species (39-fold at 9 h) and N-stearoyl species (al-fold at
9 h), compared with unsaturated fatty acid-containing species such as
anandamide (5-fold at 9 h). Noticeably, increased levels were observe
d of not only N-acylethanolamines but also several species of N-acylph
osphatidylethanolamine, potential precursors for N-acylethanolamines.
We confirmed that the rat testis microsomal fraction contains phosphod
iesterase activity catalyzing the release of N-acylethanolamine from N
-acylphosphatidylethanolamine and transacylase activity catalyzing the
formation of N-acylphosphatidylethanolamine from phosphatidylethanola
mine and phosphatidylcholine. These enzyme activities were not dramati
cally different in the microsomal fraction obtained from CdCl2-adminis
tered rat testis compared with that in the case of control rat testis,
at least when estimated in cell-free assay systems, suggesting that t
he accessibility of the substrates to the enzymes may be increased in
CdCl2-administered rat testis to generate a large amount of N-acyletha
nolamine. Possible pathophysiological implications of the augmented ge
neration of N-acylethanolamine including anandamide in CdCl2-administe
red rat testis were discussed. (C) 1998 Academic Press.