scholarly journals Tryptophan pyrrolase in haem regulation. Experiments with administered haematin and the relationship between the haem saturation of tryptophan pyrrolase and the activity of 5-aminolaevulinate synthase in rat liver

1980 ◽  
Vol 192 (2) ◽  
pp. 403-410 ◽  
Author(s):  
A N Welch ◽  
A A B Badawy

1. Administration of haematin to rats decreases 5-aminolaevulinate synthase activity in whole liver homogenates. 2. An inverse relationship between this decrease and the increase in saturation of apo-(tryptophan pyrrolase) with haem is observed during the initial phase of treatment with haematin. 3. Significant changes in both functions are caused by a 1 mg/kg dose of haematin, whereas the maximum effects are achieved by the 5 mg/kg dose. 4. Prevention by allopurinol of the conjugation of exogenously administered haematin with apo-(tryptophan pyrrolase) renders this haem available for further repression of 5 aminolaevulinate synthase. 5. The various aspects of the relationship between synthase activity and the haem saturation of tryptophan pyrrolase are discussed.

1980 ◽  
Vol 186 (3) ◽  
pp. 763-772 ◽  
Author(s):  
A A B Badawy ◽  
C J Morgan

Rat liver tryptophan pyrrolase haem is maximally depleted at 30 min after administration of a 400 mg/kg dose of 2-allyl-2-isopropylacetamide. This depletion lasts for 24 h, by which time 5-aminoleevulinate synthase activity becomes maximally enhanced. 2. though the above maximum depletion of pyrrolase haem (at 0.5h) is also produced by a 100 mg/kg dose of the porphyrogen, this does not enhance synthase activity at 24 h. It and smaller doses, however, cause a smaller but earlier enhancement of synthase activity (maximum at 2 h) and produce a similarly short-lived deplation of pyrrolase haem. 3. The depletion of pyrrolase haem and the enhancement of synthase activity by the porphyrogen are inhibited by compound SKF 525-A and phenazine methosulphate, and are potentiated by nicotinamide but not by phenobarbitone. Phenazine methosulphate and nicotinamide also exert opposite effects on hexobarbital sleeping-time. 4. 2-Allyl-2-isopropylacetamde also the depletes pyrrolase haem in vitro. It does so in liver homogenates of control rats in the presence, and in those of phenobarbitone-treated rats in the absence of added NADPH. 5. A discussion of the present results in relation to previous work with other haemoproteins suggests that, whereas cytochrome P-450 (haem) is primarily involved in the production of the active (porphyrogenic) metabolite(s) of 2-allyl-2-isopropylacetamide, the haem pool used by tryptophan pyrrolase may play an important role in the effects of this compound on haem biosynthesis.


1983 ◽  
Vol 215 (3) ◽  
pp. 709-710 ◽  
Author(s):  
A A B Badawy ◽  
C J Morgan ◽  
N R Davis

2020 ◽  
Author(s):  
Hee Yun Lee ◽  
Yan Luo ◽  
Cho Rong Won ◽  
Jiyoung Lee ◽  
Jeongwon Baik

BACKGROUND The use of social media or social networking sites (SNS) is increasing across all age groups, and one of the primary motives of using SNS is to seek health-related information. Although previous research examining the effect of SNS use on depression exist, studies regarding the effect of SNS use for health purpose on depression is limited. OBJECTIVE Our study aims to explore the relationship between SNS use for health purpose and depression across the four age groups (18-34 years old, 35-49 years old, 50-64 years old, and above 65 years old). METHODS A sample of 6,789 adults aged 18 and older was extracted from a 2017 and 2018 Health Information National Trends Survey (HINTS). Univariate and bivariate analyses to examine the association between each variable and four age groups were conducted. Multiple linear regression analyses to predict depression level among participants with use of SNS for health purpose were conducted. RESULTS SNS use for health purpose and depression were positively associated for three age groups but not for those 65 years or older (=0.13, P<0.05; =0.08, P<0.05; =0.09, P<0.05). Income and self-reported health status indicated an inverse relationship for all age groups. The relationship with marital status differed based on age group with 18 and 34 years old showing an inverse relationship (=-0.13, P<0.01) while 65 years or older showing a positive relationship (=0.06, P<0.05). Gender was positively associated among those in the 35-49 years old (=0.09, P<0.05) and 65 years or older (=0.07, P<0.05). Being Non-Hispanic White was positively associated with depression among 50-64 years old (=0.07, P<0.001) and 65 years or older (=0.08, P<0.05). CONCLUSIONS Age-tailored education on determining accurate and reliable information shared via SNS is needed to reduce depressive symptoms.


1954 ◽  
Vol 206 (1) ◽  
pp. 471-481 ◽  
Author(s):  
Ivan D. Frantz ◽  
Nancy L.R. Bucher ◽  
Henny S. Schneider ◽  
Naomi H. McGovern ◽  
Ruth Kingston

1966 ◽  
Vol 241 (2) ◽  
pp. 304-308
Author(s):  
Olga Greengard ◽  
N. Mendelsohn ◽  
G. Acs

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 972
Author(s):  
Susana Santiago ◽  
Itziar Zazpe ◽  
Cesar I. Fernandez-Lazaro ◽  
Víctor de la de la O ◽  
Maira Bes-Rastrollo ◽  
...  

No previous study has assessed the relationship between overall macronutrient quality and all-cause mortality. We aimed to prospectively examine the association between a multidimensional macronutrient quality index (MQI) and all-cause mortality in the SUN (Seguimiento Universidad de Navarra) (University of Navarra Follow-Up) study, a Mediterranean cohort of middle-aged adults. Dietary intake information was obtained from a validated 136-item semi-quantitative food-frequency questionnaire. We calculated the MQI (categorized in quartiles) based on three quality indexes: the carbohydrate quality index (CQI), the fat quality index (FQI), and the healthy plate protein source quality index (HPPQI). Among 19,083 participants (mean age 38.4, 59.9% female), 440 deaths from all causes were observed during a median follow-up of 12.2 years (IQR, 8.3–14.9). No significant association was found between the MQI and mortality risk with multivariable-adjusted hazard ratio (HR) for the highest vs. the lowest quartile of 0.79 (95% CI, 0.59–1.06; Ptrend = 0.199). The CQI was the only component of the MQI associated with mortality showing a significant inverse relationship, with HR between extreme quartiles of 0.64 (95% CI, 0.45–0.90; Ptrend = 0.021). In this Mediterranean cohort, a new and multidimensional MQI defined a priori was not associated with all-cause mortality. Among its three sub-indexes, only the CQI showed a significant inverse relationship with the risk of all-cause mortality.


1957 ◽  
Vol 225 (2) ◽  
pp. 735-744
Author(s):  
Henry Kamin ◽  
Mildred A. Koon ◽  
Philip Handler
Keyword(s):  

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