Differential expression and regulation of integral membrane protein 2b in rat male reproductive tissues.
OBJECTIVE
To examine the expression and regulation of integral membrane protein 2b (Itm2b) in rat male reproductive tissues during sexual maturation and under different treatments by in situ hybridization.


METHODS
Testis, epididymis, and vas deferens were collected on days 1-70 to examine Itm2b expression during sexual maturation. To further examine the regulation of Itm2b, adult rats underwent surgical castration and cryptorchidism. Ethylene dimethane sulfonate and busulfan treatments were carried out to test the regulation of Itm2b after destruction of Leydig cells and germ cells.


RESULTS
In testis, Itm2b expression was moderately detected in the adluminal area of seminiferous cords on days 1-10, and detected at a low level in the spermatogonia on days 20 and 30. The Itm2b level was markedly increased in Leydig cells from day 20 to day 70. In epididymis and vas deferens, Itm2b was detected from neonate to adults, and the signal gradually increased in accordance with sexual maturation. Itm2b expression was significantly downregulated in epididymis and vas deferens of castrated rats, and strongly stimulated when castrated rats were treated with testosterone. Cryptorchidism led to a significant decline of Itm2b expression in testis and caput epididymis. Itm2b expression in epididymis and vas deferens was significantly decreased after the Leydig cells were destroyed by ethylene dimethane sulfonate. Busulfan treatment produced no obvious change in Itm2b expression in epididymis or vas deferens.


CONCLUSIONS
Our data suggested that Itm2b expression is upregulated by testosterone and might play a role in rat male reproduction.
Rengaraj
Deivendran
D
College of Life Science, Xiamen University, Xiamen 361005, China.
Liang
Xiao-Huan
XH
Gao
Fei
F
Deng
Wen-Bo
WB
Mills
Nathaniel
N
Yang
Zeng-Ming
ZM
D000818:Animals; D001483:Base Sequence; D002066:Busulfan / Q000494:pharmacology; D017931:DNA Primers; D004822:Epididymis / Q000187:drug effects / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D012741:Sexual Maturation; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D014649:Vas Deferens / Q000187:drug effects / Q000378:metabolism*
D017931:DNA Primers; D008565:Membrane Proteins; C530674:integral membrane protein 2b, rat; D002066:Busulfan