Estrogenic alkylphenols induce cell death by inhibiting testis endoplasmic reticulum Ca(2+) pumps.
Industrial alkylphenols in the environment may act as "xenoestrogens" to disrupt testicular development and decrease male fertility. Amongst possible targets for these compounds are testicular Sertoli cells, which nurture the developing sperm cells. We demonstrate that SERCA 2 and 3 Ca(2+) pumps are relatively abundant in rat testis microsomal membranes, and also in Sertoli, myoid, and TM4 cells (a Sertoli cell line). A number of estrogenic alkylphenols such as nonylphenol, octylphenol, bisphenol A, and butylated hydroxytoluene all inhibit testicular Ca(2+) ATPase in the low micromolar concentration range. These agents also mobilize intracellular Ca(2+) in intact TM4 cells in a manner consistent with the inhibition of ER Ca(2+) pumps. Alkylphenols dramatically decrease the viability of TM4 cells, an effect that is reversed by either a caspase inhibitor or by BAPTA, and is therefore consistent with Ca(2+)-dependent cell death via apoptosis. We postulate that alkylphenols disrupt testicular development by inhibiting ER Ca(2+) pumps, thus disturbing testicular Ca(2+) homeostasis.
Hughes
P J
PJ
School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
McLellan
H
H
Lowes
D A
DA
Kahn
S Z
SZ
Bilmen
J G
JG
Tovey
S C
SC
Godfrey
R E
RE
Michell
R H
RH
Kirk
C J
CJ
Michelangeli
F
F
D000818:Animals; D017209:Apoptosis; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D045166:Estradiol Congeners / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010636:Phenols / Q000494:pharmacology*; D051381:Rats; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D012708:Sertoli Cells / Q000166:cytology / Q000187:drug effects; D013737:Testis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D045166:Estradiol Congeners; D010636:Phenols; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases