Prx (peroxiredoxin) is a multifunctional redox protein with thioredoxin-dependent peroxidase activity. Prx4 is present as a secretory protein in most tissues, whereas in sexually mature testes it is anchored in the ER (endoplasmic reticulum) membrane of spermatogenic cells via an uncleaved N-terminal hydrophobic peptide. We generated a Prx4 knockout mouse to investigate the function of Prx4 in vivo. Prx4(-/y) mice lacking Prx4 expression in all cells were obtained by mating Prx4(flox/+) female mice with Cre-transgenic male mice that ubiquitously expressed Cre recombinase. The resulting Prx4(-/y) male mice were fertile, and most organs were nearly normal in size, except for testicular atrophy. The number of deoxynucleotidyl transferase-mediated dUTP nick end labelling-positive spermatogenic cells was higher in Prx4(-/y) mice than in Prx4(+/y) mice and increased remarkably in response to warming the lower abdomen at 43 degrees C for 15 min. Cells reactive to antibodies against 4-hydroxynonenal and 8-hydroxyguanine were high in the Prx4(-/y) mice and concomitant with elevated oxidation of lipid and protein thiols. The cauda epididymis of Prx4(-/y) mice contained round spermatocytes, which were not found in Prx4(+/y) mice, and displayed oligozoospermia. However, mature spermatozoa from the epididymis of Prx4(-/y) mice exhibited normal fertilization In vitro. Taken together, these results indicate that spermatogenic cells lacking Prx4 are more susceptible to cell death via oxidative damage than their wild-type counterparts. Our results suggest that the presence of Prx4, most likely the membrane-bound form, is important for spermatogenesis, but not an absolute requisite.

Pituitary folliculo-stellate cells and associated cells were studied immunohistochemically throughout the life of male and female rats. The marginal layer cells of the pars distalis and intermedia as well as the folliculo-stellate cells were immunostained with anti-S 100 protein serum. The immunostained folliculo-stellate cells in one section were identified as themselves by their ultrastructural properties on the adjacent section. Corticotrophs, thyrotrophs and prolactin cells, characterized by the stellate shape, were not immunostained with anti-S 100 protein serum. Reactivity for S-100 protein appeared on postnatal Day 6 in the marginal layer cells of the pars intermedia, and appeared on Day 10 in those cells of the pars distalis. No immunostained folliculo-stellate cells appeared before Day 6, but a few of them appeared on Day 10. Thereafter they increased in number, having more intense immunostaining with advancing age. In castrated rats, the immunostained folliculo-stellate cells appeared quite numerously, with branched cytoplasmic processes surrounding the gonadotrophs. In the thyroidectomized rats, however, folliculo-stellate cells lacked ramified cytoplasmic processes, and their topographic affinity for thyrotrophs was negligible.

These results demonstrated the increased population of ICs in the BOO guinea-pig model for the first time, and suggest that the altered distribution of ICs may contribute to the pathophysiology of bladder overactivity.

Interaction between spontaneous and neurally mediated regulation of tone in the corpus cavernosum smooth muscle (CCSM) of the rabbit was investigated.

Estrogen, if it is produced in the gastrointestinal tract, may overflow into the systemic circulation in the case of increased portal-systemic shunting. This idea is in accord with a significant step-up in serum estradiol (E2) concentration in the portal vein of rats, compared with that in the artery. Gene expression of aromatase, estrogen synthetase, was demonstrated by RT-PCR in the gastric mucosa of male and female adult rats, equivalent to that in the ovary. Aromatase activity and production of E2 in the gastric mucosa were demonstrated by (3)H(2)O assay and gas chromatography-mass spectrometry, and they were inhibited by aromatase inhibitor, 4-hydroxyandrostenedione. Conversion of (14)C-androstenedione to (14)C-E2 through (14)C-testosterone in cultured gastric mucosa was also demonstrated. Parietal cells exhibited strong signals for aromatase mRNA and immunoreactive protein by in situ hybridization histochemistry and immunohistochemistry. Estrogen receptor alpha mRNA and immunoreactive protein were demonstrated in hepatocytes by RT-PCR, in situ hybridization histochemistry, and immunohistochemistry. Total gastrectomy reduced portal venous E2 concentration, without changing systemic E2 concentration, together with down-regulation of estrogen receptor alpha mRNA level in the liver. These findings indicate that gastric parietal cells play a potent endocrine role in secreting estrogen that may function as a regulator of the gastro-hepatic axis.