Acute effects of polychlorinated biphenyl-containing and -free transformer fluids on rat testicular steroidogenesis.
Polychlorinated biphenyl (PCB)-based transformer fluids belong to a class of environmentally persistent mixtures with known toxic effects. Here, we studied the acute effects of Askarel (which contains Aroclor 1260) and two substitute transformer fluids (the silicone oil-based DC561 and the mineral oil-based ENOL C) on rat testicular steroidogenesis. Single intraperitoneal (ip; 10 mg/kg body weight) or bilateral intratesticular (itt; 25 microg/testis) injections of Askarel markedly decreased serum androgen levels 24 hr after administration. In acute testicular cultures from these animals, chorionic gonadotropin-stimulated progesterone and androgen productions were severely attenuated. When itt was injected or added in vitro, Askarel inhibited 3ss-hydroxysteroid dehydrogenase (3ssHSD), stimulated 17[alpha]-hydroxylase/lyase (P450c17), and did not affect 17ss-hydroxysteroid dehydrogenase in testicular postmitochondrial fractions. The ip-injected Askarel did not affect 3ssHSD, but inhibited P450c17, suggesting that a more intensive metabolism of peripherally injected Askarel reduces the circulating levels of active ingredients below the threshold needed for inhibition of 3ssHSD and generates a derivative that inhibits P450c17. In contrast to Askarel, itt-injection (25 microg/testis) of DC561 and ENOL C did not affect in vivo and in vitro steroidogenesis. These findings show the acute effects of Askarel, but not silicone and mineral oils, on testicular steroidogenesis.
Andric
S A
SA
Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland, USA.
Kostic
T S
TS
Dragisic
S M
SM
Andric
N L
NL
Stojilkovic
S S
SS
Kovacevic
R Z
RZ
D000818:Animals; D001140:Aroclors / Q000009:adverse effects*; D046508:Culture Techniques; D007263:Infusions, Parenteral; D008297:Male; D011078:Polychlorinated Biphenyls / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D013735:Testicular Hormones / Q000096:biosynthesis*; D013737:Testis / Q000187:drug effects / Q000502:physiology*
D001140:Aroclors; D013735:Testicular Hormones; C026987:aroclor 1260; D011078:Polychlorinated Biphenyls