Biomedical subjects

F Inoue

Publications and source records attributed to F Inoue.

167 records · Page 10Linked to original sources

PubMedDate not supplied

Formation of free radicals and active oxygen species from diethylstilbestrol and its derivatives.

Diethylstilbestrol (DES), an estrogen analogue, was converted into a free radical in alkaline dimethyl sulfoxide as well as in an H2O2/peroxidase system. The presence of the hydroxyl group of the DES molecule was essential to free radical formation. Indenestrol A (IA), a microsomal metabolite of DES, showed a paramagnetic property without enzymatic activation. The electron spin resonance spectrum of IA seemingly corresponded to that of the enzymatically formed DES radical. In an NADH/peroxidase system, DES induced concomitant production of active oxygen species, which were also produced by IA. Related compounds of IA were also examined to compare with DES and IA. The significance of the free radical is discussed in relation to the process of carcinogenesis by DES.

Dienestrol↗

PubMedDate not supplied

Intraperitoneal administration of ascorbic acid delays the turnover of 3H-labelled cortisol in the plasma of an ODS rat, but not in the Wistar rat. Evidence in support of the cardinal role of vitamin C in the progression of glucocorticoid synthesis.

The purpose of this investigation was to reproduce in rats the enhancing effect of vitamin C on adrenal glucocorticoid production, a phenomenon that has been repeatedly observed in our human experiments. Here, we tried to assess the impact of vitamin C pretreatment on the turnover of exogenous 3H-labelled cortisol tracer in rats. 500 mg ascobic acid in 15 ml isotonic liquid per rat was administered intraperitoneally into rats of the experimental group, and 15 ml physiological saline per rat was similarly introduced into rats of the control group. At various times after the loading of either vitamin C or saline, 3H-labelled cortisol, 20 muc/0.5 ml saline/rat, was injected subcutaneously into rats of both the experimental and control groups. Thirty minutes later, all rats were sacrificed by exsanguination, and the radioactivity content was measured in the lipophilic fractions as well as in the purified corticosteroid compounds of blood, adrenal, testis and liver samples. To test the specificity of vitamin C action, experimental results from scurvy-prone ODS rats were compared with those of scurvy-resistant Wistar rats. Results obtained are as follows: a) the practice of vitamin C loading markedly delayed the turnover of 3H-cortisol in both the plasma lipophilic fraction and the plasma cortisol fraction, a finding which indicates that the above vitamin C pretreatment enhanced the release of endogenous glucocorticoid in such as to delay the turnover of the tracer cortisol in plasma. b) The above "dilution" effect of endogenous glucocorticoid surge was very distinct in both the lipophilic fraction and the cortisol fraction of ODS rats, and was less distinct (lipophilic fraction) or insignificant (cortisol fraction) in Wistar rats, a finding to indicate that the observed effect of vitamin C was of physiological significance. c) The responses of the adrenal glands, testes and liver to vitamin C pretreatment were generally more distinct in ODS rats than in Wistar rats, but varied from one organ to another. The significance of the functional linkage between vitamin C and adrenal glucocorticoid, which has been confirmed both in both the humans and rats in our laboratory, was discussed in the light of the historical development of vitamino-endocrinology.

Adrenal Glands↗

PubMedDate not supplied

Free radical chemistry of cigarette smoke and its implication in human cancer.

Multiple components in cigarette smoke were analyzed for their ability to form active oxygen species using a spin trapping agent, 5, 5-dimethyl-1-pyrroline-N-oxide. The main source of O2 and H2O2 was ascribed to polyphenols in a particulate phase, whereas a synergistic effect was also observed between these polyphenols and nicotine. The vapor phase contained a factor which produced OH from H2O2 which was identified as carbonyl sulfide. Nitric oxide in the vapor phase did not show such reactivity. The formation of an active oxygen species in cigarette smoke could provide an important clue to elucidate the mechanism of tobacco carcinogenesis, since they show genotoxic effects to induce DNA strand breaks as well as epigenetic effects to act as cell proliferation signals.

Humans↗

PubMedDate not supplied

Formation of free radicals from steroid hormones: possible significance in environmental carcinogenesis.

In order to clarify the mechanism of environmental carcinogenesis, steroid hormones were checked for formation of free radicals and active oxygen species. In alkaline DMSO in vitro, glucocorticoids, progestines, androgens and estrogens exhibited distinct ESR signals with characteristic hyperfine structures. Accumulated data on a great number of steroid derivatives suggest that an unpaired electron is localized at position 20 in the case of glucocorticoids, whereas it is at position 3 in other steroid hormones. Since experimental conditions include oxygenation reactions and more or less reflect enzymatic reactivity, the results obtained suggest further study on the physiological formation of free radicals from steroid hormone is warranted. Although detection of the free radicals of steroid hormones in several enzyme systems was limited to estrogens, evidence suggests that glucocorticoids as well as androgens may also share the physiological formation of free radicals. The production of active oxygen species was confirmed in certain cases.

Animals↗

PubMedDate not supplied

Ectopic breast cancer: a case report and review of the Japanese literature.

We report a rare case of ectopic breast cancer in a 68-year-old woman, successfully treated by surgery and chemotherapy. We found 37 cases including our case in the Japanese literature between 1933 to 1997. Our review demonstrated that the clinical features of Japanese patients who developed ectopic breast cancer was similar to previous foreign reports.

Aged↗