Back to Search
Start Over
A protein from polymorphonuclear leukocytes (LEM) which affects the rate of hepatic amino acid transport and synthesis of acute-phase globulins.
- Source :
-
Endocrinology [Endocrinology] 1975 Mar; Vol. 96 (3), pp. 651-61. - Publication Year :
- 1975
-
Abstract
- A proteinaceous secretion from phagocytizing polymorphonuclear leukocytes, termed "leukocytic endogenous mediator" (LEM), has been shown to have marked effects on hepatic amino acid transport and RNA and protein synthesis. A single injection of LEM results in a marked accumulation of labeled nonmetabolizable model amino acids in the liver of normal rats. The LEM-stimulated uptake of amino acids by liver was observed in adrenalectomized, hypophysectomized, thyroidectomized, or diabetic rats and could not be duplicated by pharmacological doses of a large variety of hormones. In addition, LEM stimulated an increased uptake of alpha-aminoisobutyric acid by isolated livers during their perfusion in vitro. LEM also stimulated an increased incorporation of orotic acid into hepatic RNA of intact rats, especially into the bound ribosomal fraction. This increased synthesis of RNA preceded an enhanced hepatic production of a number of the acute-phase plasma globulins. LEM did not stimulate the adenylate cyclase-cAMP system in liver and was not found to utilize this system as a second messenger. Thus, the effects of LEM in stimulating hepatic amino acid transport appear to be direct, without mediation by other hormones, and to be independent of cAMP. On the other hand, the ability of LEM to stimulate RNA and acute phase globulin synthesis in liver may require the presence of physiological quantities of hormones such as adrenal corticoids.
- Subjects :
- Adenylyl Cyclases metabolism
Adrenal Glands physiology
Adrenalectomy
Aminoisobutyric Acids metabolism
Animals
Cyclic AMP metabolism
Diabetes Mellitus metabolism
Hypophysectomy
Liver enzymology
Orotic Acid metabolism
Perfusion
Pituitary Gland physiology
RNA biosynthesis
RNA, Ribosomal biosynthesis
Rats
Stimulation, Chemical
Thyroid Gland physiology
Thyroidectomy
Amino Acids metabolism
Leukocytes
Liver metabolism
Neutrophils
Proteins metabolism
Serum Globulins biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 0013-7227
- Volume :
- 96
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 163730
- Full Text :
- https://doi.org/10.1210/endo-96-3-651