PheroQuirk
12-05-2005, 03:34 PM
http://
www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1688354&dopt=Citation (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1688354&dopt=Citation)
Differential
metabolism of pregnenolone by testicular homogenates of humans and two species of macaques. Lack of synthesis of the
human sex pheromone precursor 5,16-androstadien-3 beta-ol in nonhuman primates.
Weusten JJ, van der Wouw MP,
Smals AG, Hofman JA, Kloppenborg PW, Benraad TJ.
Department of Medicine, St. Radboud Hospital, University of
Nijmegen, The Netherlands.
In previous reports we described the early time sequence in in vitro [4-14C]
pregnenolone metabolism in human and rat testicular homogenates and, apart from a difference in the preferred route
of the conversion of pregnenolone to testosterone, we demonstrated the presence of delta 16-synthetase activity in
human but not in rat testes. In the study of testicular function higher monkeys are increasingly used as a model for
human reproduction. The availability of testes from 2 different species of macaques (rhesus and crab eating monkeys)
enabled us to compare the in vitro metabolism of pregnenolone in these testes with human testes. The pattern
obtained in both monkey species were very similar, but completely different from those found in man. The delta 4
pathway was the preferred route for the conversion of pregnenolone to testosterone in the monkeys tested, the delta
5 pathway in the humans. delta 16-Synthetase activity, a prerequisite for the synthesis of the sex pheromone
precursors 5,16-androstadien-3 beta-ol and 4,16-androstadien-3-one, was clearly measurable in the human but not in
the monkey testicular homogenates. So far, man and boar are the only species harbouring delta 16-synthetase activity
in their testes. These in vitro data indicate that the nonhuman primates studied are not suitable models for the
study of human testicular function.
www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1688354&dopt=Citation (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1688354&dopt=Citation)
Differential
metabolism of pregnenolone by testicular homogenates of humans and two species of macaques. Lack of synthesis of the
human sex pheromone precursor 5,16-androstadien-3 beta-ol in nonhuman primates.
Weusten JJ, van der Wouw MP,
Smals AG, Hofman JA, Kloppenborg PW, Benraad TJ.
Department of Medicine, St. Radboud Hospital, University of
Nijmegen, The Netherlands.
In previous reports we described the early time sequence in in vitro [4-14C]
pregnenolone metabolism in human and rat testicular homogenates and, apart from a difference in the preferred route
of the conversion of pregnenolone to testosterone, we demonstrated the presence of delta 16-synthetase activity in
human but not in rat testes. In the study of testicular function higher monkeys are increasingly used as a model for
human reproduction. The availability of testes from 2 different species of macaques (rhesus and crab eating monkeys)
enabled us to compare the in vitro metabolism of pregnenolone in these testes with human testes. The pattern
obtained in both monkey species were very similar, but completely different from those found in man. The delta 4
pathway was the preferred route for the conversion of pregnenolone to testosterone in the monkeys tested, the delta
5 pathway in the humans. delta 16-Synthetase activity, a prerequisite for the synthesis of the sex pheromone
precursors 5,16-androstadien-3 beta-ol and 4,16-androstadien-3-one, was clearly measurable in the human but not in
the monkey testicular homogenates. So far, man and boar are the only species harbouring delta 16-synthetase activity
in their testes. These in vitro data indicate that the nonhuman primates studied are not suitable models for the
study of human testicular function.