Splenomegaly and the Circulating Red Cell

Harris, Ila M.; McAlister, J.; Prankerd, T. A. J.

doi:10.1111/j.1365-2141.1958.tb03838.x

Cited by 51 publications

(24 citation statements)

References 1 publication

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“…Endogenous bilirubin formation normally takes place primarily from senescent erythrocytes taken up in the spleen, and in hepatocytes from the Downloaded by [RMIT University] at 22:30 14 August 2015 turnover of hepatic cytochromes, particularly cytochrome P-450 (Schmid et al, 1966). Heme is taken up primarily in hepatocytes (Bissell et al, 1972a(Bissell et al, , 1972bEberhard et al, 1970;Hershco et al, 1972), or damaged erythrocytes, which are taken up mostly in the spleen and other reticuloendothelial cell-containing tissues (Harris et al, 1957;Jandl et al, 1965).…”

Section: Suppression Of Hyperbilirubinemia By Metalloporphy Rinsmentioning

confidence: 95%

Chemistry and Biology of Heme Effect of Metal Salts, Organometals, and Metalloporphyrins on Heme Synthesis and Catabolism, with Special Reference to Clinical Implications and Interactions with Cytochrome P-450

Beri

Chandra

1993

Drug Metabolism Reviews

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Although free porphyrins occur in nature in small quantities, no known function has been assigned to them. In contrast, heme and cobalamin, which are Fe and Co chelates of porphyrins or porphyrin derivatives, respectively, carry out crucial biological functions. Heme is the prosthetic group for a number of hemoproteins. These include myoglobin and hemoglobin, which carry out oxygen binding or transport; mitochondrial cytochromes aa3, b, c, and c3, which are important in transferring electrons; microsomal cytochrome P-450, which catalyzes mixed-function oxidations; catalase, which decomposes H2O2; peroxidase, which activates H2O2; and tryptophan pyrrolase, which catalyzes the oxidation of tryptophan. Recently, heme has also been shown to be the prosthetic group of prostaglandin and peroxide synthetase and indoleamine dioxygenase. The elegant studies of the biochemical pathway for the formation of heme demonstrated the arrangement in the porphyrin macrocycle of the carbon and nitrogen atoms originating from the eight glycine and the succinic acid molecule that are the precursors of porphyrins. There are eight enzymes involved in the synthesis of heme. The first and last three of these enzymes are localized in mitochondria, while the intermediate enzymes are localized in cytosol. The catalytic site of HMOX recognizes metalloporphyrins with central metal atoms other than iron; it favors some of these metalloporphyrins over heme as a potential substrate, sometimes by a large factor, permitting the synthetic heme analogue to serve as a potent competitive inhibitor of HMOX reaction. Since these synthetic metalloporphyrins do not bind molecular oxygen, they are not metabolically degraded by ring rupture and do not add to the body pool of bile pigment. One possible consequence of this competitive inhibition of heme degradation is suppression of bile pigment formation to such a degree that excessive plasma levels of bilirubin may be diminished. The studies of Drummond and Kappas (1981) and later studies in rats, mice, monkeys, and man, and also our studies have proved the latter phenomenon. The compound does not appear to affect the metabolic disposition of preformed bilirubin but inhibits biliary bilirubin excretion derived from the metabolism of endogenous or exogenous heme. Whether some of the effect of Sn-PP on naturally occurring or experimentally induced jaundice in animals reflects diversion of heme to nonheme to oxygenase-dependent pathways of heme metabolism, or whether a pathway which is normally latent becomes activated concurrent with HMOX inhibition is not known.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Suppression Of Hyperbilirubinemia By Metalloporphy Rinsmentioning

confidence: 95%

Chemistry and Biology of Heme Effect of Metal Salts, Organometals, and Metalloporphyrins on Heme Synthesis and Catabolism, with Special Reference to Clinical Implications and Interactions with Cytochrome P-450

Beri

Chandra

1993

Drug Metabolism Reviews

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“…Determination of rate of disposal of material from blood by measurement of accumulation of tracer in a recipient reservoir was described by Keating, Power, Berkson, and Haines (12) for I131 taken up by the thyroid gland and for the (14) employed it in studies of the splenic uptake of autologous cells. The first two of these groups of investigators pointed out that the exponential rate constant of the accumulation curve of an irreversible receiving reservoir is identical to that of the exponential decay curve of blood.…”

Section: Discussionmentioning

confidence: 99%

Influence of Spleen Size and Portal Pressure on Erythrocyte Sequestration*

Holzbach¹,

Shipley²,

Clark³

et al. 1964

J. Clin. Invest.

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“…Platelet levels remained elevated as long as the infusion was continued and returned to base line or slightly below within 10 to 15 minutes after it was terminated. After infusion of 4.0 to 9.0 jug epinephrine per kg (average, 6.0 jug per kg), platelet increases in nine normal subjects (recorded in Figure 5) ranged from 25 to 709o', averaging 459o'. On four occasions, epinephrine was given to normal subjects 2 to 24 hours after transfusion of 51 Crlabeled autogenous platelets.…”

Section: Fig 5 Per Cent Change In Platelet Levels After Infusion Ofmentioning

confidence: 99%

Pooling of platelets in the spleen: role in the pathogenesis of "hypersplenic" thrombocytopenia.

Aster¹

1966

J. Clin. Invest.

799

435

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Splenomegaly and the Circulating Red Cell

Cited by 51 publications

References 1 publication

Chemistry and Biology of Heme Effect of Metal Salts, Organometals, and Metalloporphyrins on Heme Synthesis and Catabolism, with Special Reference to Clinical Implications and Interactions with Cytochrome P-450

Chemistry and Biology of Heme Effect of Metal Salts, Organometals, and Metalloporphyrins on Heme Synthesis and Catabolism, with Special Reference to Clinical Implications and Interactions with Cytochrome P-450

Influence of Spleen Size and Portal Pressure on Erythrocyte Sequestration*

Pooling of platelets in the spleen: role in the pathogenesis of "hypersplenic" thrombocytopenia.

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