Immunolocalization of gastrin-releasing peptide (GRP) in the uteroplacenta of the mouse deer.

The considerable phylogenetical differences between mouse deer and other ruminants have been established by means of DNA sequence analysis and anatomical observations. To clarify the physiological role of the uteroplacenta of the mouse deer, immunohistochemical observation was attempted by using GRP, which has been suggested as a novel regulatory peptide in the female reproductive tract, as an indicator to compare with other ruminants. Strong positive reactions for the GRP were detected in the uterine glands of the pregnant animals, but not in the non-pregnant ones. Although the placenta of the mouse deer is categorized as a diffuse placenta that is different from other ruminants' polycotyledonary placenta, in terms of GRP immunoreactivity, the mouse deer placenta can be classified as a synepithecholial placenta like the other ruminants'. The secretion of GRP from the uterine glands is of some importance to the fetus in the mouse deer.

Immunohistochemical study on the distribution and relative frequency of endocrine cells in the stomach of the Malayan Pangolin, Manis javanica.

The distribution and relative frequency of six kinds of endocrine cells in the stomach of the Malayan pangolin, Manis javanica were studied immunohistochemically using the avidin-biotin-peroxidase complex method. The stomach of the pangolin has three regions of mucous gland, one oxyntic gland and one pyloric gland. Cells immunoreactive for chromogranin, serotonin, somatostatin, BPP and glucagon were detected in all of the gastric glands, while gastrin-immunoreactive cells were found in the entire gastric gland except for the oxyntic gland. The distribution pattern of endocrine cells in the mucous gland and pyloric gland was mainly from the middle to apical portions of the glands. The endocrine cells were rare or not detected in the basal portion of all of the mucous glands and pyloric gland, but they were also found in the basal portion of the oxyntic gland. The distribution pattern of the endocrine cells in the mucous and pyloric glands suggested that this position facilitates a quick response to the luminal ingesta. The wide distribution of gastrin-immunoreactive cells in all of the mucous glands and pyloric gland was the most remarkable finding. This distribution suggests a major function of gastrin-immunoreactive cells for the digestive process in the Malayan pangolin stomach.

Immunohistochemical localization of gastrin-releasing peptide, neuronal nitric oxide synthase and neurone-specific enolase in the uterus of the North American opossum, Didelphis virginiana.

The present study has demonstrated the immunohistochemical localization of gastrin-releasing peptide (GRP), neuronal nitric oxide synthase (nNOS) and neurone-specific enolase (NSE) in the uterus of the North American opossum. Although the presence of GRP, nNOS and NSE has been reported recently in the uterus of eutherian species this is the first description of these peptides in a metatherian species. Metatherian mammals are of interest because in these species it is the prolonged lactation phase of development that is the period of primary reproductive investment rather than intrauterine development as is true of eutherian mammals. The opossum, like other marsupial species, has a very abbreviated gestation period which in Didelphis lasts only 12.5 days. GRP was localized in the cytoplasm of cells forming the surface lining epithelium and the glandular epithelium of the opossum endometrium late in pregnancy, at 11.5 days of gestation. Likewise, immunoreactivities of nNOS and NSE were found primarily within the epithelial cells of the endometrium at 11.5 days of gestation. As these peptides and enzymes appear primarily at the time of establishment of the yolk sac placenta (between day 10 and day 12.5 gestation), the present results strongly suggest that these factors may play a fundamental role in the placentation of the opossum.

Ultrastructural localization of gastrin-releasing peptide (GRP) in the uterine gland of cow.

Gastrin-releasing peptide (GRP) is thought to act mainly as a neurotransmitter and localized almost exclusively to neurons and neuroendocrine cells. Recently, the localization of GRP in mammalian uterus and placenta has been demonstrated. Moreover, the exocrine manner of GRP release was deduced in ewes from the distribution of GRP on the uterine gland cells and its secretion as well as in the circulation. However, these reports have been examined at light-microscopic level. The present study was designed to make clear the localization of GRP in the uterine gland cells of nonpregnant and pregnant cows using an avidin-biotin-peroxidase complex (ABC) method at light-microscopic level and a pre-embedding immunogold with silver enhancement method at electron-microscopic level. The light-microscopic observation showed positive staining for GRP immunoreactivity in the supranuclear region and in the secreted materials of the uterine gland cells. At the electron-microscopic level, the supranuclear secretory granules and the secreted materials on the surface of the cell were labeled with immunogold particles representing GRP immunoreactivity in the uterine gland cells of nonpregnant and pregnant cows. Western blotting analysis showed a larger molecular form of GRP in the endometrial tissues taken from nonpregnant and pregnant cows. The present results revealed the localization of GRP in the uterine gland cells at light- and electron-microscopic levels and suggested the release of GRP from the cell into the lumen of the gland by exocrine manner.

Immunohistochemical distribution of S-100 protein and subunits (S100-alpha and S100-beta) in the swamp-type water buffalo (Bubalus bubalis) testis.

The distribution and localization of S-100 protein (S-100) and its subunits (S100-alpha and S100-beta) in the testis of swamp-type water buffalo were investigated using immunohistochemistry. S-100 was detected in the Sertoli cells in the convoluted seminiferous tubules, modified Sertoli cells lining the terminal segment of the seminiferous tubules and in the intratesticular excurrent ducts (straight tubules and rete testis). S100-beta showed the same distribution and localization with that of S-100. However, the cytoplasmic extension of the Sertoli cells in S100-beta staining showed less staining intensity compared with that of S-100. S100-alpha showed a positive staining only in the modified Sertoli cells of the terminal segment of the seminiferous tubule. Endothelial cells of blood vessels were also positive with the proteins while the Leydig and spermatogenic cells showed a negative reaction. The localization of S-100 in the testis of the water buffalo was in parallel with that of other artiodactyls which supports the hypothesis that this protein is a multifunctional protein. S100-beta in the Sertoli cells suggests that this protein is involved in establishing blood-testis barrier. Its presence in the modified Sertoli cells and in the epithelium of the excurrent ducts suggest secretory and absorptive function, respectively. Meanwhile, S100-alpha, which was detected only in the modified Sertoli cells, is involved in the secretory activity of these cells that are related to exocrine function.

Immunohistochemical localization of inhibin subunits in the testis of the bull.

The differential localization of the inhibin beta subunits betaA and betaB in the testis of adult bull was studied using specific monoclonal and polyclonal primary antibodies. Inhibin betaA- and betaB-subunits were localized only in the Sertoli cells. The inhibin betaA-subunit was observed in the cytoplasm while the betaB-subunit was localized in the nucleus. No specific findings depending on spermatogenic stages were observed among the seminiferous tubules. Moreover, the inhibin alpha-subunit was not detected in the testis of the bulls. In addition, no inhibin subunits were detected in the Leydig cells and spermatogenic cells. These findings indicate the presence of betaA- and betaB-subunits in the bull, which may suggest a possibility that activin is produced and/or stored in the Sertoli cells and regulates spermatogenesis in an autocrine/paracrine manner. Moreover, the inhibin betaB-subunit may be produced in the nucleus but the functional meaning of this is not yet clear.