Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.15 (renin)
 35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies have shown that autoreactive B cells and autoantibodies are present in pathological as well as in normal situations. In the present study, we immortalized human B cell lines from normal individuals and from patients with malignant or benign dysglobulinemia with Epstein-Barr virus and examined, after cloning, the autoantibody reactivities of the immunoglobulins secreted by these cells. Forty-two supernatants were analyzed by enzyme-immunoassay on a panel of 13 self and non-self antigens: trinitrobenzenesulfonic acid (TNP), DNA, L-glutamine, L-alanine, L-tyrosine (GAT), actin, myosin, tubulin, albumin, renin, spectrin, transferrin, thyroglobulin, myoglobin, peroxidase, and by immunofluorescence in tissue sections. Fourteen (33%) of the immunoglobulin-secreting cell lines were found to have an autoantibody function; seven secreted IgM, six IgA, and one IgG. The light chains were of the kappa type in 11 cases. The vast majority of these clones reacted with more than five antigens of the panel and all of them reacted with TNP. No correlation was found between a given isotype and an antibody specificity. More than half of these antibodies also reacted with cellular antigens present in tissue sections. None of the four cell lines secreting monoclonal antiviral antibodies reacted with any of the antigens of the panel. The results indicate that immunoglobulins secreted by human monoclonal lymphoid cell lines can have polyspecific autoantibody functions, similar to those found in normal human polyclonal antibodies, in human monoclonal paraproteins and in natural monoclonal antibodies synthesized by murine or rat clones obtained from physiologically normal animals.
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PMID:Polyspecific natural antibodies and autoantibodies secreted by human lymphocytes immortalized with Epstein-Barr virus. 283 Sep 25

1. The renal responses to the dipeptides gamma-L-glutamyl-L-dopa (gludopa) and gamma-L-glutamyl-L-tyrosine (glutyrosine) were compared when given intravenously in six normal male volunteers. 2. Gludopa is natriuretic and diuretic at a dose of 25 micrograms min-1 kg-1. At the same dose, glutyrosine had no effect on the volume or sodium content of the urine. 3. There was a 400-600-fold increase in urine dopamine output after gludopa; there was no conversion of glutyrosine to dopamine. 4. Gludopa significantly inhibited plasma renin activity, whereas with glutyrosine there was a non-significant increase. 5. Gludopa is a potent pro-drug for renal dopamine production and exerts natriuretic and hormonal effects. Glutyrosine appears to be inactive. The results support the contention that circulating L-dopa is the important physiological precursor for renal dopamine.
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PMID:A comparison of the renal actions of gamma-L-glutamyl-L-dopa and gamma-L-glutamyl-L-tyrosine in normal man. 312 18

Sections of juxtaglomerular cells from sodium-deficient rats were subjected to radioautography after a single intravenous injection of L-tyrosine-3,5 3H or of L-fucose 3H to identify the sites of synthesis and to follow the migration of newly-formed proteins and glycoproteins. As early as 2 min after injection of L-tyrosine 3H, the label was highest in the rough endoplasmic reticulum (RER), suggesting that cisternal ribosomes are sites of protein synthesis. By 60 min, much of the label had migrated from the RER to the Golgi complex. Some radioactivity was already present over specific granules by 2 min but a peak was reached at 4 h. The label over myofilaments was evident at all time intervals, indicating a certain incorporation of tyrosine into their contractile and/or structural proteins. The label over the cell surface peaked at 4 h. After injection of L-fucose 3H, there was an early and important relative specific radioactivity in the Golgi complex at 5 min with a peak at 20 min and a decrease thereafter. The label increased slightly but steadily in secretory granules and cell surface to reach maxima at 4 h. A low level of radioactivity was recorded in mitochondria at all time intervals. After injection of both fucose 3H and tyrosine 3H, the label was detected at relatively low levels in the cytosol. These results suggest that renin, as the major secretory glycoprotein of juxtaglomerular cells, is synthetized in the RER, packaged in the Golgi complex and found relatively rapidly in newly-formed secretory granules. Part of the fucose and tyrosine labels is also associated with the thick cell coat of these cells.
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PMID:Synthesis and migration of proteins and glycoproteins in juxtaglomerular cells of sodium-deficient rats. An ultrastructural radioautographic study. 706 98

To clarify further the action of acute administration of L-tyrosine in lowering blood pressure, L-tyrosine ethylester was infused intravenously into awake [deoxycorticosterone acetate (DOCA)-salt] hypertensive rats, two-kidney Goldblatt hypertensive rats, and normotensive rats. The effects of tyrosine were measured on arterial pressure, heart rate, plasma catecholamine levels, and plasma renin activity. Blood pressure and heart rate were lowered in all groups despite significant elevation of plasma dopamine in all groups and epinephrine in the hypertensive groups, norepinephrine did not rise significantly, and plasma renin activity was always found to be within the ranges expected for each model. It was concluded that tyrosine produced the progressive decline in blood pressure and heart rate by bringing about a sustained state of parasympathetic dominance, as effective sympathetic compensation did not occcur. This could be attributed to increased alpha-adrenergic activity in certain sites in brain secondary to increased catecholaminergic activity in these areas.
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PMID:Effects of tyrosine infusion in normotensive and hypertensive rats. 740 57