The disease definition according to a specific consensus conference or to The Diseases Database based on the Unified Medical Language System (NLM)
Also the link to the corresponding Mesh term has to be created
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age, sex, seasonality, etc
PATIENT RISK FACTORS
TISSUE SPECIFIC RISK FACTORS
anatomical (due its structure)
vascular (due to the local circulation)
physiopathological (due to tissue function and activity)
No correlation between Bilirubin and TSH or T4 level
The Relationship of the Anti-Oxidant Bilirubin with Free Thyroxine Is Modified by Insulin Resistance in Euthyroid Subjects, 2014
- The strong anti-oxidative properties of bilirubin largely explain its cardioprotective effects. Insulin resistance is featured by low circulating bilirubin. Thyroid hormone affects both bilirubin generation and its biliary transport, but it is unknown whether circulating bilirubin is associated with thyroid function in euthyroid subjects. Aim is to determine relationships of bilirubin with TSH, free T4 and free T3 in euthyroid subjects without type 2 diabetes mellitus (T2DM), and to assess whether such a relationship would be modified by the degree of insulin resistance.
- Low bilirubin relates to low free T4 in euthyroid non-diabetic subjects. Low normal free T4 may particularly confer low bilirubin in more insulin resistant individuals.
la bilirubina inibisce l'uptake del t4 negli astrociti
ecco l'effetto sull'ipotalamo
Cytotoxicity of bilirubin for human fibroblasts and rat astrocytes in culture. Effect of the ratio of bilirubin to serum albumin. 1996
Competitive inhibition of thyroid hormone uptake into cultured rat brain astrocytes by bilirubin and bilirubin conjugates. 1993
- Thyroid hormone (TH) metabolism is altered in cases of unconjugated hyperbilirubinemia. These effects might involve inhibition of TH uptake by their target cells. Astrocytes, which are in close contact with the membranes of brain capillaries, might be the first brain cells to come into contact with bilirubin. Cultured rat brain astrocytes were used as a model to study the effects of bilirubin and bilirubin analogues on TH uptake. The initial uptake of [125I]T3 and [125I]T4 was inhibited by unconjugated bilirubin, biliverdin, ditaurobilirubin and bilirubin glucuronides. The inhibition of T3 uptake by the bilirubin analogues was competitive. The Ki values were: unconjugated bilirubin (31 microM), biliverdin (48 microM), ditaurobilirubin (2.5 microM) and bilirubin glucuronides (1.2 microM). This last value is similar to the Km of T3 transport (0.4 microM), indicating that bilirubin glucuronides have a high affinity for the TH transport system. By contrast, the uptakes of [3H]tryptophan and ]3H]glutamine were not inhibited. These results suggest that the astrocyte plasma membrane bears specific bilirubin-interaction sites that are closely related to the TH transport system. However, uptake of [14C]bilirubin by cultured astrocytes was a non-saturable process. Binding of bilirubin to the astrocyte plasma membrane may inhibit the TH uptake and impair their metabolism and their action on the intracellular targets.
Int J Vitam Nutr Res. 1999 Jan;69(1):16-22.
Retinoic acid in association with tin-metalloporphyrins influences heme metabolism in vivo in rats.
Chandra R, Aneja R, Sharma A, Tiwari M.
Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, India.
In the current study we report the perturbation of key enzymes of the heme metabolic pathway, i.e. delta-amino levulinic acid synthase, heme oxygenase and biliverdin reductase, in vivo by administration of retinoic acid (RA) and retinoic acid in association with tin-metalloporphyrins, viz., tin-protoporphyrin (SnPP) and tin-mesoporphyrin (SnMP) in the liver, spleen, heart and lung of rats. RA at a dosing regimen of 50,000 I.U. stimulated splenic ALA-S activity, whereas co-administration of tin-metalloporphyrins with RA antagonised the RA mediated induction of ALA-S. In the other tissues viz., liver, heart and lung our results showed a diminution of ALA-S activity on RA administration, the level of repression was further attenuated when tin-metalloporphyrins were co-administered with RA. This marked suppression of ALA-S brought forth by concurrent administration of RA and tin-metalloporphyrins is suggestive of the beneficial effect of this formulation in acute attacks of porphyria, similar to heme. Furthermore, our results emphasize that the combined dosing of RA with tin-metalloporphyrins leads to a substantial decline in bilirubin levels due to a profound inhibition of HMOX in the probed tissues. The features of the combined action of RA and tin-metalloporphyrins in vivo lead to a substantial suppression of formation of the potentially toxic metabolite bilirubin, and the enhancement of disposal of the untransformed substrate (heme) of the enzyme that is inhibited. These results define some of the characteristics of a therapeutically useful formulation and represent a new therapeutic approach for the amelioration and management of hyperbilirubinemia.
bilirubin respiratory chain
Perturbation of membrane dynamics in nerve cells as an early event during bilirubin-induced apoptosis. 2002
Increased levels of unconjugated bilirubin, the end product of heme catabolism, impair crucial aspects of nerve cell function. In previous studies, we demonstrated that bilirubin toxicity may be due to cell death by apoptosis. To characterize the sequence of events leading to neurotoxicity, we exposed developing rat brain astrocytes and neurons to unconjugated bilirubin and investigated whether changes in membrane dynamic properties can mediate apoptosis. Bilirubin induced a rapid, dose-dependent increase in apoptosis, which was nevertheless preceded by impaired mitochondrial metabolism. Using spin labels and electron paramagnetic resonance spectroscopy analysis of whole cell and isolated mitochondrial membranes exposed to bilirubin, we detected major membrane perturbation. By physically interacting with cell membranes, bilirubin induced an almost immediate increase in lipid polarity sensed at a superficial level. The enhanced membrane permeability coincided with an increase in lipid fluidity and protein mobility and was associated with significant oxidative injury to membrane lipids. In conclusion, apoptosis of nerve cells induced by bilirubin is mediated by its primary effect at physically perturbing the cell membrane. Bilirubin directly interacts with membranes influencing lipid polarity and fluidity, protein order, and redox status. These data suggest that nerve cell membranes are primary targets of bilirubin toxicity.
Francon J and bilirubin
Competitive inhibition of thyroid hormone uptake into cultured rat brain astrocytes by bilirubin and bilirubin conjugates
The Relationship of the Anti-Oxidant Bilirubin with Free Thyroxine Is Modified by Insulin Resistance in Euthyroid Subjects