SANGUIFICATION IN THE LIVER.
Glycogenic function. Glycogen derived through glucose and laevulose from starch, glycerine, milk and cane sugars. Less from proteids. Peptones as a source. Its use in cell growth and heat production, in white blood cells, in contracting muscle, becoming lactic acid. Excess dissolves red globules, setting free hæmoglobin. Ammonia carbonate and asparagin increases it. Arsenic, phosphorus or antimony arrests glycogenesis. Liver increases leucocytes, and reduces size of red globules. Reduction of proteids. Fibrine formers reduced, urea formed; liver inactivity means less of soluble urea, and more of less soluble and more dangerous products. Urea increases with hepatic circulation. Hepatic disorder and suppression of urine dangerous. Red globules probably destroyed. Bile: Amount, uses, oil solvent, helps endosmosis, deodorant, stimulates glycogenesis, excretory. Source of bile pigments, tests. Bile acids, dissolve blood globules, antiseptic, tests. Bile increased by; bile absorbed from bowel, olive oil, salol, salicylates, benzoic acid and benzoates, turpentine, terpene, terpinol, euonymus, alkalies, arsenic, ether. Agents lessening biliary secretion, starvation, excess of fat, alkaline iodides, atropia, strychnia, hepatic diseases, septic duodenal fermentation. Arrest in liver of copper, iron, iodides, bromides, nicotine, quinine, morphia, curare, toxic bile products, ptomaines, toxins. Reduces toxicity of peptones, casein, ammonia salts, indol, phenol.
The liver is the goal to which most of the products of gastric and intestinal digestion are carried by the portal vein. In the hepatic cells large quantities of glycogen, 6 (C6H10O5) + H2O, are stored up after each meal. This is believed to be derived largely from the transformation of glucose, (C6H12O6) and laevulose (C6H12O6) which have been produced from starch in the alimentary canal and conveyed by the portal vein to the liver. By the liberal use of starch, glycerine, or the sugars of milk, fruit or cane, (but not mannite, or glycol, or inosite) the glycogen is very greatly increased (to 12 per cent. in the fowl), but it is diminished on a purely albuminous diet. Yet it can be produced from albuminous food, as it is always increased in the dog after a meal of flesh, and is largely present in the livers of carnivorous animals that have been fed for a month on flesh only (Landois). The peptones are therefore decomposed in the liver with the production of glycogen and such waste products as leucin and tyrosin, which are finally resolved into urea. A purely fatty diet diminishes it enormously and during prolonged abstinence it practically disappears. It passes, not into the bile, but into the hepatic veins, and the general circulation, where it serves in its decomposition to generate heat, and probably to hasten cell growth. In the vegetable and animal world, in the germinating seed, and in cartilage, muscle and epidermis of the fœtus and in the amnios, glycogen and glucose are found in abundance. The liver, too, the great center for the production of glycogen, is relatively much larger in the young and growing animal, and also in the adult animal which has great power of assimilation.
Glycogen is always present in the white blood globules so long as they maintain their vitality and amœboid movements, but when they die, it is replaced by sugar (Hoppe-Seyler). The red blood globules give up a ferment which rapidly transforms glycogen into sugar.
Glycogen and sugar are evidently of use in muscular contraction as they are always diminished in the vessels of contracting muscles (Sanderson), being converted into lactic acid (Bernard).
Forced muscular movements soon expel glycogen from the dog’s liver, passing it into the blood, and there the excess of glycogen dissolves the red blood globules. If glycogen is injected into the blood, achrodextrin and hæmaglobin appear in the urine (Landois).
Ammonia carbonate and asparagin, or glycin, with a carbhydrate diet produced in rabbits a considerable increase of glycogen (Rohmann).
Poisoning by arsenic, phosphorus or antimony destroys the glycogenic function of the liver, which then fails to respond even to diabetic puncture of the medulla.
There are important changes effected in the blood globules in passing through the liver. The leucocytes are increased, the hepatic veins containing 5 or even 10 times as many as the portal vein (Bernard, Lehmann, McDonald). Their ratio to the red globules is in the portal vein 1:524 and in the hepatic veins 1:136 (Hirt). The red globules undergo marked changes, having, in the hepatic veins, a smaller size, sharper outlines, less flattening in the disc, a habit of massing together irregularly in place of adhering in rouleaux, and they dissolve less readily in water.