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Biomedical subjects

T Maruo

Publications and source records attributed to T Maruo.

At least 199 records · Page 11Linked to original sources
PubMed1976

Studies on in vitro synthesis and secretion of human chorionic gonadtropin and its subunits.

Human chorionic tissues were cultivated in vitro in they presence of 3H-proline in order to study the synthesis of the hCG and its subunits by the placenta. After terminating the culture, tissue extracts and media were individually gel-filtrated on Sephadex G-100. The eluted fractions were radioimmunoassayed for hCG, hCGalpha and hCGbeta and were measured for 3H-radioactivity. Label incorporation was determined by immunoprecipitation. Elution profiles of tissue extracts showed the existence of large immunologic forms of hHCG, hCGalpha and hCGbeta emerging near the void volume. The amounts of these large immunologic species in chorionic tissue gradually decreased during the course of cultivation. 3H-proline was almost exclusively incorporated into the large immunologic forms of hCG, hCGalpha and hCGbeta within the chrionic tissue during the 5-hour exposure. A great quantity of hCGalpha was found in the media after the 3-day culture, while the amount of hCGbeta found in the media was minute. After a 15-minute pulse, the 3H-radioactivity peak within the chorionic tissue appeared in the void volume, conicidental with hCG immunoreactivity. During the chase period, there was shift of the 3H-radioactivity peak associated with hCG immunoreactivity from the void volume to the more retarded area. In the media until after the 60-minute chase, no labeled hCG and its subunits appeared. Within the media after 3-hour chase, no labeled hCG peak associated with 3H-radioactivity was more retarded on Sephadex G-100 than that within the tissue extract after the 15-MINUTE pulse. These results suggest that the large immunologic forms of hCG, HCGalpha and hCGbeta are synthesized as the earliest detectable biosynthetic forms and that the may then be converted to small molecule species. In the culture of molar trophoblastic tissues after a 15-minute pulse, considerable amounts of hCG and its subunits accompanied by high 3H-radioactively had already been secreted into the media. These observations suggest that protein synthesis by molar trophoblastic tissue is markedly enhanced as compared with that by normal chorionic tissue and that immunoreactive materials synthesized in molar trophoblastic tissue may be secreted more radily than those synthesized a in normal chorionic tssue.

Chorionic Gonadotropin↗
PubMed1976

In vitro biosynthesis of human chorionic follicle stimulating hormone.

In order to explore the possibility that human chorionic FSH (hCFSH) may be synthesized in vitro by the placenta and secreted into the culture media, chorionic tissue of the first trimester was cultivated in the radioactive medium prepared byadding 3H-proline and/or 14C-glutamic acid. Purification of biosynthesized hCFSH from the media was carried out by a combination of Sephadex G-100 gel filtration, DEAE-cellulose chromatography and polyacrylamide disc-gel electrophoresis...

Animals↗
PubMed1975

Some biological properties of human chorionic follicle stimulating hormone.

The biological properties of human chorionic FSH (hCFSH) for rat ovaries were investigated. Highly purified hCFSH had similar response to the ovarian augmentation test as bovine FSH and significantly enhanced 3H-thymidine uptake by granulosa cells and theca cells in the ovary of hypophysectomized rat. In contrast, highly purified hCG little responded to the ovarian augmentation test and had no effect on 3H-thymidine uptake by the ovary. These results indicate that hCFSH may promote the follicular growth of ovary resulting from granulosa cell proliferation and its enlargement. In addition, freshly harvested porcine granulosa cells were employed in an in vitro system to investigate specific binding of hCFSH to ovarian receptor. Radioiodinated hCFSH (125I-hCFSH) and hCG (125I-hCG) were respectively incubated with cell suspensions. Binding of these hormone preparations was proportional to the cell number and increased with the time of incubation through 120 minutes. The binding ability of 125I-hCFSH to the cells was greater than that of 125I-hCG. Increasing concentrations of unlabeled hCFSH in the incubation mixture progressively inhibited the uptake of 125I-hCFSH by granulosa cells. Unlabeled hCG was not able to compete with 125I-HCFSH binding. The similar phenomenon to inhibit the binding of 125I-hCG to the cells was also recognized in the presence of unlabeled hCG. These findings suggest that granulosa cell has at least two different types of receptor sites: one for hCFSH and the other for hCG.

Animals↗