Topic:Hepatic Function
Hepatic function in horses involves the liver's role in various physiological processes, including metabolism, detoxification, and the synthesis of essential proteins and bile. The liver is responsible for processing nutrients absorbed from the digestive tract, converting them into energy, and storing them for future use. It also plays a vital role in detoxifying the blood by metabolizing drugs and toxins. Additionally, the liver synthesizes proteins necessary for blood clotting and immune function, as well as producing bile to aid in the digestion and absorption of fats. This page aggregates peer-reviewed research studies and scholarly articles that explore the liver's functions, its regulation, and its impact on equine health.
Variations of plasma enzymes in the pony and the dog after carbon tetrachloride administration. Adult female dogs or pony mares were subjected to a nonlethal dose of CCl4 (0.5 ml/kg of body weight). Amounts of several plasma enzymes thought to be indicative of hepatic disease were monitored. Plasma enzymes alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase (ALP), arginase, gamma-glutamyltransferase (GGT), and iditol dehydrogenase (ID), as well as total plasma bilirubin, were determined in these animals before and after the administration of the CCl4. In the dog, GGT was not significantly increased, whereas ALP values were increased during days 1 to 6. In the...
Effect of pyrrolizidine alkaloid-induced hepatic disease on plasma amino acid patterns in the horse. Plasma amino acid patterns were studied in 6 clinically normal adult horses during the course of hepatic disease induced by feeding them plants containing pyrrolizidine alkaloids. At death, there were significant (P less than 0.01) increases in glutamine, proline, tyrosine, asparagine, lysine, histidine, alanine, phenylalanine, methionine, aspartic acid, and ornithine values. There were no significant changes in glycine, valine, isoleucine tryptophan, and arginine values. There were significant (P less than 0.01) decreases in citrulline. Ammonia increased 4-fold. Alpha-Aminoadipic acid and alp...
Correlation of dermal-epidermal laminar lesions of equine hoof with various disease conditions. Dermal and epidermal laminar lesions were correlated with acute intestinal, primary hepatic, septicemic, chronic laminar, and acute laminar diseases. Horses with acute intestinal disease had edema in the secondary dermal laminae. Those with hepatic disease had increased keratinization of the secondary epidermal laminae. Septicemia caused increased keratin formation in the primary and secondary epidermal laminae. Chronic laminitis caused architectural changes of the epidermal laminae characterized by hyperplasia and keratin formation of the basal epidermal layer. Horses with acute laminitis had...
Alterations in horse blood cell count and biochemical values after halothane anesthesia. Quantitative changes in hematologic and serum biochemical values associated with prolonged general anesthesia produced by known alveolar doses of halothane in oxygen were determined in six young, healthy horses under laboratory conditions. In addition, 25 young equine patients anesthetized for shorter periods under clinical conditions were similarly (except hematologic values) prospectively evaluated. In normal horses, muscle- and hepatic-derived serum biochemical values were mildly increased immediately after anesthesia. Values after anesthesia remained at greater than base-line values for up...
Plasma concentration of iditol dehydrogenase (sorbitol dehydrogenase) in ponies treated with aflatoxin B1. Twelve clinically normal Shetland ponies were allocated to one of four treatment groups. Aflatoxin B1 was administered at the dosage level of 2 mg/kg of body weight to group A, 1 mg/kg to group B, and 0.5 mg/kg to group C; a placebo was given to group D (controls). Plasma samples were assayed at 4-hour intervals for iditol dehydrogenase (ID) (sorbitol dehydrogenase) concentrations as an indicator of hepatic damage. One of the ponies in group A died 68 hours after dosing; another pony in group A died 76 hours after dosing. All other animals survived the experiment. The means of peak ID values w...
Graft versus host reactions in foals with combined immunodeficiency. Nine foals with combined immunodeficiency were given hepatic and thymus cells from 68- to 110-day-old (gestational age) fetuses or peripheral blood lymphocytes from nonrelated horses. Clinical signs and lesions consistent with graft vs host reaction were observed in eight of the foals. Diarrhea was observed in these 8 foals, and ulcerative dermatitis, stomatitis, or glossitis was detected in 6 of the 8 foals. Histopathologic changes consisting of necrosis and lymphocyte infiltration were observed in liver, skin, alimentary tract, and less frequently in lymphoid tissues. Changes in complete blo...
Hepatic pathology of experimental Parascaris equorum infection in worm-free foals. The pathological changes associated with the migration through the liver of P. equorum larvae were investigated. Twenty pony foals were killed at intervals of 2 to 185 days after a single infection with 160 or 8000 P. equorum eggs and 4 pony foals were killed at intervals of 94 to 144 days after twice weekly infections of 50 eggs from birth. At post-mortem examination the macroscopic changes included the development of focal haemorrhages and small, white diffuse or nodular lesions.
Microscopic lesions were found mainly around the portal triads and consisted of infiltration by cells, including...
Comparative studies on serum arginase and transaminases in hepatic necrosis in various species of domestic animals. Serum concentrations of arginase, glutamic pyruvic transaminase (SGPT) and glutamic oxaloacetic transaminase (SGOT) in dogs, cats, horses, cattle, sheep and pigs were determined before and after oral administration of CCl(4) at doses known to cause hepatic necrosis. Following CCl(4) administration, serum concentration of arginase and SGOT increased to a level of diagnostic significance in all animals. SGPT increased markedly in dogs and cats and marginally in 1 of 3 cattle and 2 of 3 pigs. In the surviving animals, the serum concentration of arginase returned to normal range much earlier than ...
Direct colorimetric determination of serum arginase in various domestic animals. A direct colorimetric method for the determination of serum arginase activity in various domestic animals is described. Serum arginase activity in healthy mature dogs, cats, horses, cattle, sheep, and pigs ranged from 0 to 14 IU/L. Serum arginase activity increased considerably in these animals during experimental hepatic damage induced by oral administration of carbon tetrachloride.
The effects of exercise and adrenaline infusion upon the blood levels of propranolol and antipyrine in the horse. There are now several examples showing that experimentally induced changes in hepatic blood flow can have a marked effect upon the elimination of certain high clearance drugs. Changes in hepatic blood flow produced by exercise might therefore be expected to influence the clearance of these drugs. There was an increase of up to 100%, compound to control values, in the plasma levels of propranolol in horses given either d- or dl-propranolol, 0.2 mg/kg b.wt., and then subjected to sustained exercise for 30 minutes. There was, however, no similar increase with exercise in the plasma levels of anti...
[Experimental infection of horses with Fasciola hepatica]. Ten pony foals were infected with Fasciola hepatica; five animals received up to 1000 metacercariae orally, the remaining animals received up to 80 specimens of 24 hours old adulescariae intraperitoneally. The rate of development of the parasites varied in a wide range between 0,2 and 41%. Most of the liverflukes were found in animals severely infected with strongyles in the same time. Only 22 weeks after oral infection, the flukes had reached a length of 20 mm and sexual maturity. Fasciola-eggs could not be detected in the feces.
The influence of hepatic microsomal amidopyrine demethylase activity on halothane hepatotoxicity in the horse. The hepatotoxic effect of oral halothane in the horse is increased by pretreatment with phenobarbitone or DDT but not by chlorpromazine. Phenobarbitone and DDT increase the activity of hepatic amidopyrine N-demethylase but chlorpromazine does not. Carbon disulphide protects the liver of the horse against halothane.
Effect of bile acid on hepatic excretion and storage of bilirubin in ponies. Endogenous bilirubin uptake from plasma and biliary bilirubin excretion were determined in ponies with chronic biliary T-tube fistulas. Excreted bile was quantitatively recovered. Uptake was calculated from the plasma disappearance of 14C-labeled bilirubin. Biliary bilirubin excretion was determined directly in excreted bile. When bile acid excretion was low (during continuous drainage without bile acid replacment), bilirubin excretion was 37% less than uptake. Uptake and excretion were essentially identical when taurocholic acid was infused to replace bile acids. After depletion of the bile a...
Evaluation of xylazine as a sedative and preanesthetic agent in horses. Xylazine administered intramuscularly (IM) to horses at the dose level of 2 mg/kg was an effective sedative and preanesthetic for thiamylal sodium narcosis or thiamylal sodium and halothane anesthesia. Evaluation of response of cardiovascular, respiratory, and hepatic function did not indicate serious untoward effects, although cardiac and respiratory rate decreased, calculated vigor of left ventricular contraction decreased, calculated peripheral vascular resistance increased, and transient innocuous cardiac arrhythmias occurred. Effects of the anesthetics used on respiratory function (blood ...
Effects of fasting on hepatic function in ponies. Hepatic function was measured, using sulfobromophthalein sodium (BSP) in fed and fasted ponies. In the 1st experiment, single injections of BSP were administered, and the rate of removal of BSP from plasma was determined. Fasting decreased the rate of BSP removal from plasma, as indicated by increased half-time (t 1/2). In the 2nd experiment, BSP was infused for 5 hours, and its clearance from plasma was determined. Fasting decreased BSP clearance. In the 3rd experiment, BSP was infused consecutively at 2 dose rates, and maximal excretion and hepatic storage were determined. Although fasting d...