Liver organization

Zhang, L., et al. Cloning and functional expression of a human liver organic cation transporter. Mol. Pharmacol. 1997, 51, 913-921. 

After the determination of organ weights and macroscopic examinations the tissues are processed for histo-pathological evaluations. For this they are fixed in formalin or equivalent solutions, or they are frozen (important for the diagnosis of increased fat content in a tissue, e.g. in the liver, organic solvents would dissolved the fat) trimmed to small parts, put into paraffin blocks, cut with a microtome, and stained (hematoxylin-eosin, or special staining for fat and/or collagen etc.). 

In situ liver perfusion is the most reliable method to determine the relative rate of metabolism and the expected metabolic products for the species being tested because it exposes the drug to the entire liver organ in a fashion that most closely resembles the in vivo condition. " However, the cost and time-consuming nature of the in situ experiment precludes rapid testing for metabolism during the discovery phase. Also, this method is not applicable to human experimentation for obvious reasons. 

BCRP, MXR, ABC-P ABCG2 Placenta, intestine, breast, liver Organic compounds including many common drugs Apical 142... 

Pang, K.S., Wang, P.J., Chung, A., and Wolkoff, A.W. (1998) The modified dipeptide, enalapril, an angiotensinconverting enzyme inhibitor, is transported by the rat liver organic anion transport protein. Hepatology, 28, 1341-1346. 

An important question remains why do cardiac glycosides selectively affect the heart although they are distributed from the bloodstream to the kidneys and liver, organs rich in ATPase ... 

Vitamin B,2 is produced by the growth of certain micro-organisms, and occurs also in liver, being the extrinsic anti-pernicious anaemia factor the isolation of which was sought for many years. 

Iodine occurs to a minute extent (less than 0.001 %) in sea water, but is found in greater concentration, combined in organic form, in certain seaweeds, in oysters and in cod livers. Crude Chile saltpetre, or caliche contains small amounts of sodium iodate, NalOj. from which iodine can be obtained (see below). Some insoluble iodides, for example liiose of silver and mercury(II), occur in Mexico. Iodine is found in the human body in the compound thyroxin in the thyroid gland deficiency of iodine in diet causes enlargement of this gland (goitre). 

Adrenocortical insufficiency Organ transplants Liver disease Adrenogenital syndrome Nephrotic syndrome Acute spinal cord injury Hyp ere alemia Hematologic disorders Myasthenia gravis Neoplastic disease... 

The elemental homeostasis is the particularity of total homeostasis of organism, the alteration of the parameters of this system may result in pathological changes. The liver is the organ where the detoxication processes take place. The elemental content of the liver may reflect the pathological processes which occur not only in the liver but also in the whole organism. 

The ability to identify and quantify cyanobacterial toxins in animal and human clinical material following (suspected) intoxications or illnesses associated with contact with toxic cyanobacteria is an increasing requirement. The recoveries of anatoxin-a from animal stomach material and of microcystins from sheep rumen contents are relatively straightforward. However, the recovery of microcystin from liver and tissue samples cannot be expected to be complete without the application of proteolytic digestion and extraction procedures. This is likely because microcystins bind covalently to a cysteine residue in protein phosphatase. Unless an effective procedure is applied for the extraction of covalently bound microcystins (and nodiilarins), then a negative result in analysis cannot be taken to indicate the absence of toxins in clinical specimens. Furthermore, any positive result may be an underestimate of the true amount of microcystin in the material and would only represent free toxin, not bound to the protein phosphatases. Optimized procedures for the extraction of bound microcystins and nodiilarins from organ and tissue samples are needed. 

Chirazymes. These are commercially available enzymes e.g. lipases, esterases, that can be used for the preparation of a variety of optically active carboxylic acids, alcohols and amines. They can cause regio and stereospecific hydrolysis and do not require cofactors. Some can be used also for esterification or transesterification in neat organic solvents. The proteases, amidases and oxidases are obtained from bacteria or fungi, whereas esterases are from pig liver and thermophilic bacteria. For preparative work the enzymes are covalently bound to a carrier and do not therefore contaminate the reaction products. Chirazymes are available form Roche Molecular Biochemicals and are used without further purification. 

Systemie poisons attaek organs other than the initial site of eontaet. The eritieal organs are the kidneys, liver, blood and bone maiTow. 

---