No abstract

Neuronal aromatase, the enzyme that catalyzes the conversion of androgens to estrogens, is involved in brain sexual differentiation, the regulation of reproductive behavior, and gonadotropin secretion. We have previously reported that aromatase P450 (AromP450) protein expression is enhanced by both androgens and estrogens in the principal nucleus of the bed nucleus of the stria terminalis (prBST) and posterodorsal part of the medial amygdaloid nucleus (pdMAm) of the adult rat but is not altered in the central amygdaloid nucleus (CeAm) even after sex-steroid withdrawal or supplementation. Here, we have evaluated, via in situ hybridization with digoxigenin-labeled cRNA probes, the sex-steroidal regulation of brain AromP450 mRNA in the prBST, pdMAm, and CeAm of orchidectomized and adrenalectomized adult male rats treated with sesame oil, testosterone (1 mg/rat/day), dihydrotestosterone (1 mg/rat/day), or 17beta-estradiol (2 microg/rat/day) for 6 days. AromP450-mRNA expression in the prBST and pdMAm was markedly reduced in orchidectomized/adrenalectomized rats treated with sesame oil but strongly enhanced by testosterone or dihydrotestosterone and significantly reinstated by 17beta-estradiol. These results are essentially consistent with those of AromP450 protein expression and thus indicate that enhanced AromP450-protein expression in the prBST and pdMAm reflects transcriptional upregulation and/or post-transcriptional stabilization of its mRNA by sex steroids. In the CeAm, despite moderate AromP450-protein expression, the mRNA has never been detected with or without sex-steroidal manipulations, indicating that the putative sex-steroid-insensitive AromP450 mRNA in the CeAm may be distinct from that in the prBST and pdMAm or, if it occurs at all, expressed at much lower levels.

The anti-serum against an unknown human placental antigen complex X-P2 (hPAX-P2) immunohistochemically recognizes three putative molecules (hPAX-P2S, hPAX-P2N, and hPAX-P2R), each of which is associated with the stigmoid bodies (STBs), necklace olfactory glomeruli (NOGs), or reticulo-filamentous structures (RFs) in the rat brain. The STBs also contain huntingtin-associated protein 1 (HAP1), and the HAP1-cDNA transfection induces STB-like inclusions in cultured cells. In order to clarify the relationship between hPAX-P2S and HAP1 isoforms (A/B), we performed Western blotting, immuno-histo/cytochemistry for light- and electron-microscopy and pre-adsorption tests with HAP1 deletion fragments. The results showed that the anti-hPAX-P2 anti-serum recognizes HAP1(474-577) of HAP1A/B in Western blotting and strongly immunostains HAP1A-induced STB-like inclusions but far weakly detects HAP1B-induced diffuse structures in HAP1-transfected HEK 293 cells. In the rat brain, immunoreactivity of the anti-hPAX-P2 anti-serum for the STBs was eliminated by pre-adsorption with HAP1(474-577), whereas no pre-adsorption with any different HAP1 fragments can suppress immunoreactivity for the NOGs and RFs, which were not immunoreactive to anti-HAP1 anti-serum. These findings indicate that hPAX-P2S, which is distinct from hPAX-P2N and hPAX-P2R, is identical with STB-constituted HAP1 and that the HAP1-induced/immunoreactive inclusions correspond to the hPAX-P2-immunoreactive STBs previously identified in the brain.

No abstract

To clarify the mechanism of implantation, relationship between positioning of the mouse embryo in the uterus and distribution of uterine glands along the long axis of the uterine horn was examined by three-dimensional remodelling of the uterine endometrium. There were two unique regions in the endometrium. Uterine glands were distributed widely from mesometrial to anti-mesometrial side in one region. It was localized from lateral to anti-mesometrial side in another. These different regions were alternately aligned throughout the uterine horn. The number and position of embryos was consistent with that of the latter region. This study suggests that the type of distribution of uterine glands is closely related to the positioning of the embryo in mice.