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Biomedical subjects

C E Cornelius

Publications and source records attributed to C E Cornelius.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effect of bilirubin infusion on excretion of bilirubin and biliverdin in rabbits.

Intravenous infusion of bilirubin (BR) at 171 micrograms/min/kg into rabbits resulted in biliary concentration of BR increasing from 3.8 (control) to 243 mg/dl and BR excretion increasing from 1.7 to 66 micrograms/min/kg. BR infusion resulted in biliary concentrations of biliverdin (BV) increasing from 9.1 to 30 g/dl and BV excretion increasing from 4.2 to 8.2 micrograms/min/kg. BR infusion produced a progressive decline in bile flow. BV was the predominant bile pigment in control rabbits fed either an alfalfa-based or chlorophyll-free diet. These results imply that rabbits can oxidize BR to BV.

Animals↗
PubMed1981

Hepatic Billrubin-IX-alpha-Glycosyltransferase Activities in Animals Excreting Primarily Biliverdin into Bile.

A wide variation was observed in hepatic bilirubin-IX-alpha uridine diphosphate (UDP) glucuronyl, glucosyl and xylosyl transferase activities among yellow rat snakes, pin fish, chickens, turkeys, sea turtles, alligators, nutria and rats. Lower hepatic enzyme activities were observed in fish, snakes, turtles, and avian species with intermediate enzyme activities present in the livers of nutria and alligators. Hepatic glycosyltransferase activities were greater in the biliverdin-excreting species which are known to excrete readily an exogenous bilirubin load. Hepatic enzyme activities and the biliary transport maxima of bilirubin-IX-alpha are closely correlated.

Journal Article↗
PubMed1981

Choleresis and bile pigment excretion in the nutria.

Mean excretory rates of endogenous biliverdin (BV) and bilirubin (BR) in nutria were determined to be 6.0 +/- 1.0 and 0.67 +/- 0.10 microgram/min/kg, respectively. Endogenous bile flow was 33 +/- 7.0 microliter/min/kg. Infusion of sodium taurocholate at rates above 0.1 mumol/min/kg resulted in cholestasis. Hepatic transport maxima for BR conjugates following the infusion of unconjugated BR were 120 and 130 micrograms/min/kg. Although nutria excrete predominantly BV like avian and reptilian species, they differ by readily excreting an exogenous load of unconjugated BR.

Animals↗
PubMed1980

Hepatic bile pigment excretion and erythrocyte turnover in various species.

Endogenous bile pigment excretory rates have now been recorded in fifteen species, and the following review briefly compares the excretion per unit of body weight in animals of varying sizes, attempts to determine if any correlation exists between bile flow and endogenous pigment excretion and discusses bile pigment excretion in relation to mean erythrocyte survival time and metabolic rate. Graphs and one table illustrating pigment metabolism and erythrocyte replacement are presented. Differences between animals excreting primarily biliverdin as opposed to bilirubin are discussed, with special attention being given throughout the article to mammals and their individual differences. Accepted theory concludes that the rate of endogenous bile pigment excretion is primarily dependent upon hemoglobin catabolism. However, further studies will be necessary to clarify basic physiological mechanisms in order to substantiate any theory concerning the correlation of erythrocyte turnover with metabolic rates.

Journal Article↗
PubMed1979

A new animal model with hyperbilirubinemia: the indigo snake.

An unconjugated hyperbilirubinemia has been observed in all species of normal indigo snakes. The plasma clearance of large organic anions such as sulfobromophthalein and unconjugated bilirubin was markedly delayed when compared to other snake species. Endogenous bile flow and biliverdin and bilirubin excretory rates and the excretion of bile pigments after a bilirubin load were measured in various snakes. The indigo snake represents a new animal model in which to study mechanisms important to hepatic anion uptake and biliary transport.

Animals↗
PubMed1976

Hypercholeresis in turkeys following the ingestion of Crotalaria spectabilis seeds.

Young female turkeys received diets containing Crotalaria spectabilis seeds for 18 weeks. Mean values for total bile flow, biliary bile acid excretion, bile acid-dependent flow and bile acid-independent flow were significantly higher in crotalaria-fed turkeys than in controls. The hypercholeresis observed in crotalaria-fed birds involved both bile acid-dependent and bile acid-independent components of bile. Crotalaria-fed turkeys developed biliary hyperplasia. Liver weights were similar in the two groups. Since increases in 14C-erythritol clearances paralleled increases in total bile flow in crotalaria-fed turkeys (14C-erythritol bile to plasma ratios were similar in both groups), it was evident that the hypercholeresis in crotalaria-fed turkeys did not involve the ductal/ductular component of bile. Little or no ductal/ductular bile flow occurred in either group since total bile flow was equal to erythritol clearance and extrapolation to zero erythritol clearance yielded zero bile flow rates in both groups. Crotalaria-fed turkeys exhibited significantly higher biliary concentrations of chlorides (associated with lower sodium , potassium and bicarbonate concentrations) than did control birds. Validation of the use of 14C-erythritol clearance for the estimation of canalicular bile flow in turkeys was provided both by substantial decreases in bile to plasma 14C-erythritol concentration ratios following the injection of avian vaso-active intestinal peptide and the failure to demonstrate chromatographically the presence of radioactive metabolites of 14C-erythritol in plasma.

Animals↗
PubMed1975

Experimental liver diseases.

The use of animal models in the experimental production of liver diseases similar to those of man is still in its infancy. There is a need to discover new models more closely related to counterpart syndromes in man in the fields of hepatorenal syndrome, neonatal jaundice, Wilson's disease, cholelithiasis, viral hepatitis, biliary atresia, and cirrhosis, to mention only a few. With the continued indiscriminate inbreeding of companion animals as well as the planned inbreeding of laboratory animals, there is little doubt that many more will soon be available. The current availability of mutant rats and sheep with bilirubin transport defects has allowed for a better understanding of how organic anions are transported by the liver. Many other currently available experimental animal models herein briefly reviewed have been only superficially studied. It is the intent of this chapter to provide for post-doctoral students an appreciation for the many animal model systems available for experimental hepatic research.

Alkaloids↗
PubMed1975

Biliverdin and bilirubin excretion in the turkey.

Mean endogenous bile flow in 11 turkeys was 0.81 plus or minus 0.52 mul/g of the liver per minute (10.4 plus or minus 5.3 mul/Kg of body weight per minute). Endogenous biliverdin and bilirubin excretory rates were 0.59 plus or minus 0.31 and 0.058 plus or minus 0.018 mug/g of liver per minute (7.6 plus or minus 3.6 and 0.76 plus or minus 0.23 mug/Kg of body weight per minute), respectively. Mean concentrations of biliverdin and bilirubin in endogenous bile were 92 plus or minus 55 and 8.9 plus or minus 5.2 mg/100 ml, respectively. Livers constituted 1.36 plus or minus 0.22 percent of the body weight. Thin layer chromatographic studies revealed a heterogeneity of bilirubin conjugates in bile.

Animals↗
PubMed1975

Heterogeneity of bilirubin conjugates in several animal species.

Bile was collected from various domestic and wild species (alligators, armadilirubin diazotized and subjected to thin-layer chromatography fro the separation of conjugates (as azo-dipyrroles). Diazotized canine conjugated bilirubin had Rf values in agreement with those previously reported by other; bilirubin conjugates were related to their known glycosidic composition. Variations were observed in the relative amounts of the various mono- and diconjugates among animals within species. However, it was apparent that characteristic patterns of bilirubin conjugation occur in certain animal species. Intravenous infusion of between 0.03 and 0.61 mg of bilirubin/Kg into cats resulted in little or no change in the relative percentages of the various conjugates of bilirubin to glucuronic acid in the cat continues to be the major excretory pathway under conditions of bilirubin load.

Animals↗
PubMed1972

Renal radial fibrosis in mutant Southdown sheep with congenital hyperbilirubinemia.

Kidneys from 7 mutant Southdown sheep with congenital hyperbilirubinemia, aged from 1 to 5 years were examined. Renal biopsies were taken from another mutant at 3 months and 12 months of age. At 3 months, lesions consisted of thin radial bands of myxomatous tissue in the medullary rays and atrophy of the adjacent collecting tubules. By 1 year collagen had replaced myxomatous tissue. Grossly, the kidneys were normal until 2 years when they became red and gray mottled and stained with bilirubin. The capsules stripped readily to reveal fine granular surfaces in sheep over 2 years of age. On the cut surface of the cortex were 0.5 mm wide radial gray streaks of fibrous tissue. Progressive fibrosis in sheep 2 to 5 years old resulted in a thinning of the cortex. With increasing fibrosis, the number of cystic tubules increased progressively. Protein casts and hyaline droplet degeneration were numerous in sheep over 2 years of age. Plasma cells and lymphocytes were frequently seen in the fibrous bands, and bile pigment was visible in the macrophages in the fibrous tissue and in the epithelium of the proximal tubule cells. Polyuria, low specific gravity urine and reduced effective renal plasma flow and glomerular filtration rates resulted from the replacement of specialized proximal tubule cells by low cuboidal cells, fibrous tissue separating the capillaries from the loops of Henle, destruction of glomeruli and segregation of glomeruli in fibrous bands. The kidney lesions may be determined by the same gene responsible for the hepatic excretion defect for bilirubin.

Age Factors↗