Biomedical subjects

K Wakai

Publications and source records attributed to K Wakai.

At least 73 records · Page 4Linked to original sources

PubMed1995

Evaluation of a low-dose intravesical bacillus Calmette-Guérin (Tokyo strain) therapy for superficial bladder cancer.

To examine whether intravesical instillation of low-dose bacillus Calmette-Guérin (BCG) therapy is effective with low toxicity, we reviewed data for 111 patients with superficial bladder cancer (stages Ta and T1). Among them, 74 received the BCG treatment for prophylaxis of intravesical recurrence after transurethral resection, and the remaining 37 therapeutically for Ta or T1 tumours. The patients were divided into two groups by instillation dose of BCG (Tokyo 172 strain): 40 mg (n = 55) and 80 mg (n = 56), and statistically compared for recurrence, antitumour effect and toxicity. The mean instillations were done 8.4 times in the 40 mg dose group and 8.6 times in the 80 mg dose group. Among the 74 patients with BCG therapy for prophylaxis those with a previous episode of bladder cancer treatment (n = 47) experienced a significantly (p = 0.006) shorter recurrence-free interval than those with no episode (n = 27). Among 47 patients with a previous treatment episode, those receiving the 80 mg dose demonstrated a significantly longer recurrence-free interval than those given the 40 mg dose (p = 0.03). Among the 27 patients without previous treatment no significant difference in recurrence-free intervals was found between the two dose groups. Univariate and multivariate analyses using Cox's proportional hazards model confirmed the above findings. The recurrence index was also significantly reduced after BCG therapy in the 80 mg and 40 mg groups and similar antitumour effects for Ta or T1 tumours were observed in the two dose groups. The degree of toxicity due to BCG therapy was significantly (p = 0.02) lower with the 40 mg dose. The present study suggests that (1) a 40 mg BCG low-dose (Tokyo 172 strain) regimen is useful for preventing recurrence, with sufficient therapeutic efficacy and low frequency of toxicity, among patients without a previous treatment, and (2) prophylactic effects with the 80 mg dose regimen are much superior for previous treatment cases.

Aged↗

PubMed1995

Epidemiology of breast cancer in Japan.

BACKGROUND: A recent increase in the numbers of deaths and incident cases of breast cancer among Japanese women stimulated the authors to summarize the trends in female breast cancer mortality and incidence rates in Japan. METHODS: The number of deaths from female breast cancer was obtained from the national vital statistics. Estimated incidence rates, based on several cancer registries, were also used for the analyses. The trends in the age-adjusted and age-specific rates were examined. Age and birth cohort effects on the incidence and mortality rates were examined, using multiplicative models. RESULTS: The age-adjusted mortality rate has been increasing since the 1960s (4.1 per 100,000 population in 1950 and 6.6 in 1991, adjusted by the World Population). The age-adjusted incidence rate has also been rising since 1975. Age-specific rates have been increasing particularly in the age range 40-79 years. The multiplicative models disclosed an increasing cohort effect for the mortality and incidence rates among women born after 1900. Decreasing mortality and incidence rates after menopause were ascribed by the models to strong cohort effects. CONCLUSIONS: The recently increasing trend was believed to be consistent with changed risk factors among Japanese women. The age effect on female breast cancer incidence rate in Japan was concluded to be similar to that in Western populations.

Adult↗

PubMed1995

Tea consumption and lung cancer risk: a case-control study in Okinawa, Japan.

To disclose the relationship between tea consumption and lung cancer risk, we analyzed the data from a case-control study conducted in Okinawa, Japan from 1988 to 1991. The analysis, based on 333 cases and 666 age-, sex- and residence-matched controls, provided the following major findings. (a) The greater the intake of Okinawa tea (a partially fermented tea), the smaller the risk, particularly in women. For females, the odds ratios (and 95% confidence intervals) for those who consumed 1-4, 5-9, and 10 cups or more of Okinawan tea every day, relative to non-daily tea drinkers, were 0.77 (0.28-2.13), 0.77 (0.26-2.25) and 0.38 (0.12-1.18), respectively (trend: P = 0.032). The corresponding odds ratios for males were 0.85 (0.45-1.55), 0.85 (0.45-1.56) and 0.57 (0.31-1.06) (trend: P = 0.053). (b) The risk reduction by Okinawan tea consumption was detected mainly in squamous cell carcinoma. Daily tea consumption significantly decreased the risk of squamous cell carcinoma in males and females, the odds ratios being 0.50 (95% confidence interval 0.27-0.93) and 0.08 (0.01-0.68), respectively. These findings suggest a protective effect of tea consumption against lung cancer in humans.

Adenocarcinoma↗

PubMed1995

[Epidemiological study of tsutsugamushi disease in Gunma prefecture. A special field study and serotype].

An epidemiologically investigated of invasion of Rickettsia tsutsugamushi, inhabitant of mites and serum sample from patients with Tsutsugamushi disease in Gunma prefecture from 1984 to 1994 was made. Our data clearly indicated that Rickettsia tsutsugamushi was not located but widely spreaded throughout the Prefecture. Mites on rodents, were classified into 4 genus and 12 species and about 15% of them were Leptotrombidium pallidum and Leptotrombidium scuttellare, well known virulent vectors. The highest incidence rate of this disease was observed in the northwest area of the Prefecture from October to December, while a smaller number of patients occurred in other areas and in other months. About fifty percent of the serum samples from the patients were positive to the Karp strain. These results suggest that the major cause of this disease is the Karp strain and the disease could occur potentially in various areas of the Prefecture.

Animals↗

PubMed1995

Significance of urinalysis for subsequent kidney and urinary tract disorders in mass screening of adults.

To evaluate dipstick urinalysis as a predictor of subsequent kidney and urinary tract disorders in apparently healthy adults, we designed a cross-sectional, prospective, and retrospective study within a cohort. The severity of proteinuria was significantly (p < 0.01) associated with the amount of pathological casts, whereas hematuria without proteinuria was not. The frequency of subsequent serum creatinine increase (0.3 mg/dl/5 years or more) was significantly enhanced (from 0.4% to 7.3% along with the severity of proteinuria, whereas it was not related to the severity of hematuria. Patients who subsequently developed renal failure and glomerulonephritis exhibited hematuria (11.1-32.1%) less frequent than proteinuria (62.3-83.3%). Even those with renal tumors or stones showed infrequent (14.3-27.9%) hematuria. Thus, urine protein and occult blood have different implications in mass screening.

Adult↗

PubMed1995

[Lifestyles and renal damage--association of smoking, drinking and physical activity with subsequent proteinuria].

To examine the role of lifestyles in the subsequent development of renal damage, the association of smoking, drinking and physical activity with subsequent proteinuria was investigated utilizing a longitudinal study. The subjects were 7,701 males aged 20-84 years, who participated in health examinations at Aichi Prefectural Center of Health Care, Nagoya, Japan, both in 1989-1990 and 1992-1993, and who showed no proteinuria at the first examination. Lifestyles at the first examination were compared between 140 men with, and 7,561 men without, newly developed proteinuria at the second examination. Age-adjusted odds ratios (ORs) of lifestyle factors for proteinuria were computed, and further the ORs were adjusted for age, systolic blood pressure, fasting plasma glucose level and other covariates obtained using multiple logistic regression analysis. Major significant findings which emerged from the present study were as follows. (a) The greater the consumption of alcohol per day, the higher the risk of subsequent proteinuria (trend p = 0.003). Heavy drinkers who consumed more than 58 g of alcohol per day experienced an increased risk (OR relative to non-drinker: 2.52). (b) Those who exercised less than once a week, and those who avoided walking even a short distance were at an increased risk (OR: 1.46, 1.55, respectively). Heavy drinking and low physical activity were found to be significantly associated with an increased risk of subsequent proteinuria even after adjusting for the covariates. An increasing risk of subsequent proteinuria with number of cigarette smoked per day was observed by univariate and multivariate analysis but without statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

[Social activities in the elderly].

In order to clarify the status of social activities in the elderly, and to investigate an association between social activities and age, ADL, and geographical area, a self-administered questionnaire survey was conducted on the aged population in four areas in Japan. Social activities was defined as "activities which required contact with society" and was measured by 4 major facets of social activity, which were based on 21 questions on job activity, socially-related activities, learning activities, and personal activities. A total index was also developed by summarizing the 4 major facets as an indicator of whether the elderly is socially active or not as a whole. The following major findings emerged from this survey: (1) Rank correlation coefficients between each item which comprised 4 major activities were relatively high; (2) Excluding two activities, "shopping" and "attending senior school", aged men were more actively involved than women; (3) Trend in degrees of social activities differed by age among the 4 major facets, i.e., (a) job activity decreased with age, (b) socially-related activities and learning activities increased up to about 75 years old, and decreased thereafter, (c) personal activities were unaltered up to about 80 years old, and then decreased, and; (4) The elderly with low ADL had the lowest representation among the "highly active" in 4 major facets and total index as well.

Activities of Daily Living↗

PubMed1995

[Validity of photographical dietary assessment; a preliminary analysis].

We estimated nutritional intake from color photographs taken of meals with a 35-mm camera, and compared them with the values calculated from the menu. Among 21 meals examined, the coefficient of correlation between the values by the photo method and those from examining the menu was appreciably high; 0.842 in energy, 0.828-0.931 in three major nutrients, and 0.745-0.940 in vitamins and minerals. The differences between the photo method and menu observation were 0-14.8% on average, and the coefficient of variation of the differences was 9.1-32.3%. Estimation of salt was, however, very poor, and the agreement was lower due to the cooking method used. Some differences were found among the dietitians in estimated values of several nutrients. The running cost was approximately 87-yen per meal, which may pose a problem for large-scale dietary surveys. Compared with the use of record, recall, and frequency questionnaire methods, the photo method was easily used by participants, especially those not used to cooking, and could be applied to eating out or for take-out food. Moreover, this method may provide not only quantitative data but also qualitative including eating atmosphere. When estimation is difficult due to the ingredients or recipe, combined use with record or recall methods can facilitate estimation. This photo method is thus considered to be a valid and feasible means of dietary assessment.

Food Analysis↗

PubMed1994

Mechanism of inhibitory actions of minocycline and doxycycline on ascitic fluid production induced by mouse fibrosarcoma cells.

Semisynthetic tetracyclines (TCNs) are used for the management of malignant pleural effusions as sclerosing agents. However, their precise mechanism of actions are uncertain. In the present study, the mechanism of inhibitory effects of minocycline (MINO) and doxycycline (DOXY), on the accumulation of ascitic fluid induced by mouse fibrosarcoma (Meth-A) cells were investigated using male mice. Meth-A cells inoculated intraperitoneally elicited 2.5-4 ml of bloody ascites 10 days after implantation. The production of ascitic fluid was suppressed in a dose-related manner by daily intraperitoneal injections of MINO or DOXY, whereas vehicle (normal saline with 0.01N HCl) did not exert a significant effect. The inhibitory activity of these two substances was quite similar; one mg/mouse of MINO or DOXY inhibited the accumulation of fluid by 87% and 84%, respectively. The survival rate of Meth-A-bearing mice treated with MINO or DOXY was higher than that of the controls. Macroscopic examination of the peritoneal cavity did not reveal any obvious effects, such as adhesions, in mice treated with either MINO or DOXY. In vitro studies showed that MINO and DOXY suppressed Meth-A cell growth with IC50s of 5 microM and 8 microM, respectively. Maximal suppression (95%) was achieved at MINO and DOXY concentrations of 25 microM. The above observations suggest that MINO and DOXY inhibit the accumulation of ascites by a direct effect on Meth-A cell growth. Therefore, it appears that TCNs injected into the pleural cavity to manage malignant effusions in man exert their activity, at least in part, by suppressing malignant cell growth.

Animals↗

PubMed1994

[Epidemiological remarks on low serum cholesterol level and cancer risk of all sites].

Epidemiological studies which examine an association between low serum cholesterol level and cancer risk of all sites were reviewed and a summary of major findings are as follows: (1) In most reports, low serum cholesterol level, which associated with cancer of all sites, cancer deaths/incidence occurred within a few years after cholesterol measurement were performed. This short-term association is believed to be a preclinical cancer effect, i.e., preclinical cancer itself reduces serum cholesterol level. (2) A long-term inverse association between serum cholesterol and cancer risk of all sites was observed in some studies. This association cannot be explained by either a preclinical cancer effect or by chance. The epidemiological implications of this association was discussed in depth. (3) A long-term inverse association between serum cholesterol level and cancer mortality/incidence was observed mainly in men, but not in women. In a few studies which reported an inverse association in women, follow-up periods were rather short. (4) A few epidemiological studies conducted in Japan also detected a long-term inverse relationship between serum cholesterol level and cancer risk of all sites in men, but not in women. Since low serum cholesterol level may possibly be a risk factor for cancer of all sites, further investigation involving experimental studies on animals and longitudinal population-based study appear to be necessary for confirmation of this factor.

Adolescent↗

PubMed1993

Inhibition of human pancreatic cancer cell (MIA PaCa-2) growth by cholera toxin and 8-chloro-cAMP in vitro.

The effects of cholera toxin (CT) and 8-chloro-cAMP (8-Cl-cAMP) on cell growth were investigated using two human pancreatic carcinoma cell lines (MIA PaCa-2, Panc-1). CT, which catalyses the ADP ribosylation of Gs, suppresses the proliferation of MIA PaCa-2(PC) cells. CT at the low dose of 0.1 pg ml-1 was inhibitory of PC cell growth, and the maximum suppression (70%) was achieved at a CT concentration of 100 pg ml-1. This phenomenon was reversible. The production of cAMP by CT (100 pg ml-1) in PC cells was enhanced 320-fold compared with the control. In addition, cAMP analogues (8-Cl-cAMP, 8-Br-cAMP) and forskolin decreased the growth rate of PC cells in a dose-dependent manner. These results support the view that CT suppresses PC cell growth by stimulating cAMP production. Conversely, Panc-1 cells were far less sensitive to CT in cell growth and cAMP production. 8-Cl-cAMP was also less effective on Panc-1 cell growth. The binding of an insulin-like growth factor (IGF)-I and transforming growth factor (TGF)-alpha, which has been shown to stimulate PC cell growth in an autocrine manner, to PC cells was not modified in cells treated with CT or 8-Cl-cAMP. The results suggest that the inhibitory actions of these substances do not occur at the level of the receptor for IGF-I or EGF/TGF-alpha. We have previously shown that phorbol esters, which decrease the binding of TGF-alpha to PC cells, has an anti-proliferative activity on these tumour cells. Inhibited cell growth by maximum suppressive dose of CT or 8-Cl-cAMP was further inhibited by TPA. In addition, an oncogene product of K-ras which is commonly activated in pancreatic cancer, was increased by CT and 8-Cl-cAMP. It is concluded that CT and 8-Cl-cAMP inhibit PC cell growth, presumably in a similar manner, and their mechanism(s) of action may be different from that of TPA. The anti-proliferative effect of CT or 8-Cl-cAMP was enhanced by TPA, implying that the combination of these substances results in increased inhibition of the PC cell growth.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1993

Prognostic significance of selected lifestyle factors in urinary bladder cancer.

To examine the prognostic significance of lifestyle factors in urinary bladder cancer, we conducted a follow-up study of 258 incident bladder cancer patients, who were originally recruited in a case-control study in metropolitan Nagoya. Information on individual survivals was obtained from the computer data-file of the tumor registry of the Nagoya Bladder Cancer Research Group. Univariate analyses revealed significant associations of 5-year survivorship with educational attainment, marital status, drinking habits and consumption of green tea in males, and age at first consultation, histological type and grade of tumor, stage and distant metastasis in both sexes. After adjustment for age, stage, histology (histological type and grade) and distant metastasis by means of a proportional hazards model, drinking of alcoholic beverages was significantly associated with the prognosis of bladder cancer in males. Its adjusted hazard ratio was 0.46 (95% confidence interval: 0.26-0.79), favoring patients who had taken alcoholic beverages. In detailed analysis, ex-drinkers and all levels of current drinkers demonstrated hazard ratios smaller than unity, although no clear dose-response relationship was detected. No prognostic significance was found for such lifestyle factors as smoking habit, uses of artificial sweeteners and hairdye, and consumption of coffee, black tea, matcha (powdered green tea) and cola.

Adult↗

PubMed1991

Transforming growth factor (TGF)-alpha in human milk.

Transforming growth factor (TGF)-alpha and epidermal growth factor (EGF) were measured in human milk by means of homologous radioimmunoassay. As previously reported, EGF concentration in the colostrum was approximately 200 ng/ml and decreased to 50 ng/ml by day 7 postpartum. The value of immunoreactive (IR)-TGF-alpha was 2.2-7.2 ng/ml, much lower than that of EGF. In contrast to EGF, the concentration of IR-TGF-alpha was fairly stable during the 7 postpartum days. There was no relationship between the concentrations of IR-TGF-alpha and IR-EGF, suggesting that the regulatory mechanism in the release of the two growth factors is different. On gel-chromatography using a Sephadex G-50 column, IR-EGF appeared in the fraction corresponding to that of authentic human EGF, while 70%-80% of the IR-TGF-alpha was eluted as a species with a molecular weight greater than that of authentic human TGF-alpha. Although the physiological role of TGF-alpha in milk is not known, it is possible that it is involved in the development of the mammary gland and/or the growth of newborn infants.

Epidermal Growth Factor↗

PubMed1988

Thyroid volume and serum thyroglobulin levels in patients with acromegaly: correlation with plasma insulin-like growth factor I levels.

The pathogenesis of the goiter that is frequently found in patients with acromegaly is not known. Using ultrasonic scanning, we measured thyroid volume in 17 euthyroid patients with acromegaly and examined the relationships among thyroid size, plasma GH and insulin-like growth factor (IGF-I) levels, and serum thyroglobulin (TG) levels. The mean estimated thyroid volume in these 17 patients was 32.8 +/- 15.5 (+/- SD) mL, significantly larger than that in normal subjects (15.4 +/- 3.1 mL), and 64.7% of the patients had multinodular goiter, as identified by ultrasonography. Thyroid volume was positively correlated with plasma GH and IGF-I levels and heel-pad thickness, but not with the serum TSH level. In 7 patients, thyroid volume decreased in association with a decline in plasma GH and IGF-I levels after surgical treatment. The serum TG level was elevated in 7 of the 15 patients in whom it was measured, and the mean value was 51.7 +/- 62.7 (+/- SD) micrograms/L (normal, 12.6 +/- 6.4 micrograms/L). We found no correlations among the serum TG and TSH levels, plasma GH and IGF-I concentrations, and/or thyroid volume. However, serum TG decreased after surgical treatment, just as did plasma IGF-I. These observations together with the results of recent in vitro studies by others suggest that IGF-I is one of the factors involved in goiter formation, but the elevated serum TG levels in acromegaly are controlled not only by IGF-I but also by other factors.

Acromegaly↗

PubMed1987

Biological activities of human growth hormone and its derivatives estimated by measuring DNA synthesis in Nb2 node rat lymphoma cells.

Nb2 cell is a rat lymphoma cell line that responds to lactogens such as prolactin and human growth hormone (hGH) with an increased rate of proliferation. We explored the relationship between the biochemical events induced by hGH and its derivatives and their receptor binding activities. hGH stimulated RNA, DNA and protein synthesis of Nb2 cells as a function of time. Stimulation of RNA and protein was maximal at 2-3 h and 12 h, respectively, after the addition of hGH. DNA synthesis, measured by the rate of [3H]thymidine incorporation, reached a maximum after 18-h incubation with hGH. Stimulation of DNA synthesis was elicited by hGH in a dose-dependent manner between 0.45 and 45 pmol/l. The activity of the 20 K hGH variant in stimulating DNA synthesis was approx 30% of that of hGH. In contrast, S1-hGH, which lacks a sequence of ten amino acids (140-149) of hGH, showed a 3.2-fold greater activity than hGH. F1 (amino-terminal sequence 1-134 of hGH) was only 0.06% as active as hGH, and the activity of F2 (C-terminal 42 amino acid residue of hGH) was less than 0.01%. Both fragment 1-15 and 32-46 were without effect. The relative potencies of these hGH derivatives in stimulating DNA synthesis were similar to their relative abilities to inhibit [125I]hGH binding to lactogenic receptors on Nb2 cell. Nb2 cells provide a suitable model to study the relationship between receptor binding and the biochemical events induced by lactogens.

Animals↗

PubMed1984

Processing of human growth hormone by rat hepatocytes in monolayer culture.

The fate of cell-bound [125I]iodo-human GH ([125I]iodo-hGH) was studied in monolayer cultures of hepatocytes from pregnant and nonpregnant rats. Both the binding of [125I]iodo-hGH and its degradation were significantly higher in cells from pregnant than from nonpregnant rats. The positive correlation between the number of binding sites for hGH and the amount of degradation of [125I]iodo-hGH suggests that degradation, at least in part, is a receptor-mediated process. Degradation as a time- and temperature-dependent process was impaired by lysosomotropic compounds such as chloroquine and NH4Cl in a dose-dependent manner. Dinitrophenol, N-ethyl-maleimide, and NaN3 were also effective in preventing degradation, suggesting that an energy-requiring process is involved in degradation of [125I]iodo-hGH. Cell-bound [125I]iodo-hGH became less dissociable as a function of time of association. Degradation of [125I]iodo-hGH accelerated the dissociation of cell-bound radioactivity. Gel-filtration experiments revealed that [125I]iodo-hGH is degraded to smaller molecular species, but only a small portion of the degradation products exists within the cells. These observations suggest that receptor-bound [125I]iodo-hGH is degraded by an internalization process; lysosomal enzymes are probably responsible for the degradation of [125I]iodo-hGH, and the degraded products are rapidly released into the extracellular space.

2,4-Dinitrophenol↗

PubMed1984

Effect of phorbol esters on the release of growth hormone and prolactin from rat pituitary cells cultured in monolayer.

The effect of phorbol diester tumour promoters on the release of growth hormone (GH) and prolactin (Prl) was studied in rat pituitary cells cultured in monolayer. 12-O-tetradecanoyl phorbol-13-acetate (TPA), the most potent phorbol ester, stimulated GH accumulation in the cultured medium in a dose-dependent manner. TPA also stimulated Prl accumulation. A time course study indicated that TPA mainly stimulates release of GH. The maximal stimulation of GH release by TPA (100 ng/ml) was 3-4-fold over control. Phorbol-12,13-dibutyrate (PDB), another tumour-promoting phorbol ester, stimulated GH release to an extent similar to that of TPA, while a biologically inactive compound, phorbol-12,13-diacetate (PDA), had no effect. TPA-stimulated GH release was not affected by the presence of indomethacin, an inhibitor of prostaglandin (PG) synthesis, indicating that PG is not involved in the process of TPA-stimulated GH release. Co++, a competitive antagonist of Ca++, at 2.0 mM completely suppressed the GH release induced by TPA, and this inhibition was partially reversed by the addition of 2.0 mM Ca++. Verapamil, a Ca++ channel blocker, reduced TPA-stimulated GH release, and trifluoperazine, an inhibitor of Ca-calmodulin formation, had a similar effect. Somatostatin (SRIF) also inhibited the GH release by TPA. These observations are compatible with the idea that Ca++ may be involved in the process of TPA-stimulated GH release. Since TPA has been reported to activate a Ca++- and phospholipid-dependent protein kinase (protein kinase C), it is possible that TPA stimulate GH release by activating the enzyme. Further studies are required to clarify this point.

Animals↗

PubMed1983

Modulating effect of glutathione disulfide on thyroxine-5'-deiodination by rat hepatocytes in primary culture: effect of glucose.

To investigate whether an increase in the intracellular glutathione disulfide (GSSG) concentration actually regulates T4-5'-deiodination in intact cells, rat hepatocytes in primary culture were exposed to glutathione-oxidizing agents (diamide and tertiary butylhydroperoxide) or vinblastine, and their effects on 5'-deiodination of T4 were studied. Deiodinating activity was determined from the 125I- fraction released from [3',5'-125I]T4 added to the serum-free culture medium. Total glutathione (T-GSH) and GSSG levels were determined enzymatically. Diamide (1 mM) and tertiary butylhydroperoxide (0.5 mM) increased the GSSG fraction to approximately 40% of the T-GSH at 5 min, followed by a rapid decrease in GSSG. Glucose deprivation of the medium caused a greater GSSG level at 5 min, followed by a delayed normalization of the increased GSSG level. T4-5'-deiodinating activity was minimally decreased in hepatocytes exposed to 1 mM diamide in the presence of glucose in the medium, but was significantly inhibited in the absence of glucose. Vinblastine, in contrast, gradually and steadily increased the GSSG fraction, and by 3 h, GSSG exceeded 20% of T-GSH (at 10(-4) M vinblastine). This was accompanied by a significant inhibition of 5'-deiodinating activity. When the enzyme activity was inhibited, the T-GSH level was decreased to 40-80% of the control level, which per se cannot account for the decreased T4-5'-deiodinating activity, as reported previously. These data suggest that the increased GSSG level, but not the T-GSH concentration, modulates T4-5'-deiodination in intact cells, and that glucose stimulates the enzyme activity by maintaining glutathione in the reduced form, probably through supplying NADPH, a cofactor for GSSG reductase.

Animals↗