In the rat, catecholamine conjugates, particularly dopamine conjugates, are widely distributed in cerebrospinal fluid, sympathetically innervated tissues, plasma, erythrocytes and urine. Sulfoconjugated dopamine, norepinephrine and epinephrine are detected in small quantities, whereas glucuronoconjugation seems to occur only in dopamine, and is by far the predominant form of dopamine conjugation. On the other hand, in man, sulfoconjugation is normally the sole form of catecholamine conjugation. Glucuronoconjugated dopamine constitutes the bulk not only of dopamine, but also of total catecholamines in rat cerebrospinal fluid, plasma and urine, which sharply contrasts with the composition of catecholamines in peripheral tissues where the bulk of total catecholamines is free norepinephrine (in sympathetically innervated tissues) or epinephrine (in adrenals). Sulfo- and glucuronoconjugated catecholamines in rat cerebrospinal fluid are central in origin, whereas the adrenal medulla and peripheral postganglionic sympathetic neurons are important sources of peripheral conjugated catecholamines. In response to stress, rat plasma free catecholamine surges occur with concomitant substantial falls in sulfoconjugated dopamine, norepinephrine and epinephrine as well as glucuronoconjugated dopamine. Under stress, a large portion of rat plasma conjugated dopamine, mainly glucuronoconjugated dopamine is not only deconjugated to free dopamine, but probably also converted to free norepinephrine and epinephrine. Adrenalectomy abolishes these normal stress-induced responses to plasma conjugated catecholamines in the rat. These findings led to the following conclusions. (1) Glucuronoconjugation is an important pathway in the metabolism of central and peripheral dopamine in the rat. (2) In the metabolism of catecholamines, conjugation is qualitatively distinct from O-methylation and deamination in that conjugation represents an intermediate and reversible process, whereas O-methylatio
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68655 |
| Date | January 1982 |
| Creators | Wang, Pin-Chang. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Medicine) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000155770, proquestno: AAINK60953, Theses scanned by UMI/ProQuest. |
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