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L Barrios

Publications and source records attributed to L Barrios.

65 records · Page 4Linked to original sources
PubMed1986

Erythropoietic effects of triiodothyronine on the anemia of renal failure in rats: comparative studies with testosterone and erythropoietin.

A pronounced and significant stimulatory effect on erythropoiesis was observed in anemic uremic rats receiving either T3 (50 micrograms/kg/day) or Ep (7.5 and 15 U[units]/day) for ten days. A lack of erythropoietic response was seen after the administration of testosterone (5 mg/kg/day) for the same period of time. Renal failure and anemia were studied in partially nephrectomized rats that had received nephrotoxic doses of kanamycin (500 mg/kg/day). The marked increase in red blood cell production produced by T3 and Ep in anemic uremic rats was evident, not only from increased hemoglobin and hematocrit values in peripheral blood, but also from an elevated number of circulating reticulocytes and generally increased absolute counts of nucleated erythroid cells per milligram of bone marrow. The effects of T3 on erythropoiesis in anemic rats with renal insufficiency are in accordance with our previous report demonstrating the direct effect of thyroid hormones on marrow erythroid precursors. This effect can occur only when high levels of the free active forms of T3 are present in plasma, as can happen in the uremic rats receiving daily doses of T3. Since the possibility of producing large amounts of Ep for the treatment of the anemia associated with chronic renal failure is unlikely in the near future, utilization of T3, mainly compounds without calorigenic effects, may be a potential therapeutic alternative.

Anemia↗
PubMed1984

Salivary gamma-glutamyl transferase activity in internal diseases.

Salivary gamma-glutamyl transferase (GGT) activity was measured in 116 patients with several diseases that involved the hepatobiliary tract, pancreas, and miscellaneous disorders and in 20 normal subjects. We have found significantly elevated values of salivary GGT in cirrhosis of the liver (8.3 +/- 0.9 [mean +/- SEM] units/L), hepatic tumors (10.4 +/- 1.3 units/L), acute cholecystitis (18.3 +/- 2 units/L), acute pancreatitis (15.1 +/- 2.4 units/L), diabetic ketoacidosis (11.6 +/- 1 units/L), and Sjögren's syndrome (19.6 +/- 4.8 units/L). Salivary GGT activities were unmodified in fatty liver, infectious hepatitis, silent cholelithiasis, and mumps. Several mechanisms explain high salivary GGT activity. Measurement of salivary GGT activity in internal medicine merits further investigations to determine its potential diagnostic value.

Adult↗
PubMed1984

[Gamma-glutamyltransferase and alkaline phosphatase in the serum and saliva of patients with hepatic tumors and hepatic cirrhosis].

The authors have previously described the presence of gammaglutamyl transferase and alkaline phosphatase in the saliva of healthy individuals and of patients with hepatobiliary and pancreatic diseases. The authors show in this work the values of said enzymes in the blood serum and saliva of 23 cases of liver cirrhosis and 17 patients with liver tumors. Both enzymes increase significantly in the serum of liver tumor patients with respect to the amounts found in liver cirrhosis patients (p less than 0.005). Alkaline phosphatase increased significantly in the saliva of patients with liver cirrhosis (p less than 0.005), where as no differences were found between the two groups of patients with liver cirrhosis (p less than 0.005), where as no differences were found between the two groups of patients for the salivary gamma-glutamyl transferase. The determination of seric alkaline phosphatase and gamma-glutamyl transferase, and of salivary alkaline phosphatase may be useful for the differential diagnosis between liver cirrhosis and liver tumor.

Adult↗
PubMed1983

Lack of induction of serum gamma-glutamyltransferase in diabetes mellitus.

Some authors have suggested that carbohydrates can induce hepatic microsomal enzymes, resulting in increased serum gamma-glutamyltransferase (GGT) in diabetes mellitus. Previously we demonstrated the lack of serum GGT increases in patients with acute diabetic crises. In this work we studied serum GGT activity, blood glucose levels and glycosylated hemoglobin levels (HB A1) in 35 patients with diabetes mellitus and 27 healthy volunteers. We did not see differences in the serum GGT activity among controlled (25.05 +/- 2.72 U/l) and uncontrolled (26.44 +/- 4.05 U/l) diabetics and the control group (22.51 +/- 2.95 U/l). Also, there was no significant correlation between serum GGT and HB A1 levels in diabetic patients (r = 0.279). We think that our observations may be relevant because they support the hypothesis that hyperglycemia does not act as an enzyme-inducing agent in chronically uncontrolled diabetics and, furthermore, they indicate that in the presence of abnormal serum GGT levels in diabetics it is necessary to investigate other associated diseases.

Acyltransferases↗
PubMed1975

Direct effects of thyroid hormones on bone marrow erythroid cells of rats.

A stimulatory effect on bone marrow cellularity was observed in normal and nephrectomized rats continuously infused with T3 and T4. Results of bone marrow studies are expressed in absolute numbers of total nucleated erythroid cells per milligram of femoral marrow at the beginning and after 8 hr of continuous intravenous infusions. Administration of T3 and T4 to nephrectomized rats produced a marked and significant increase in total erythroid cells counted. After differential analyses of the nucleated erythroid elements, a significant increase in all erythroid cell types was also observed. Similar results were seen in a control group of rats in which both ureters have been previously ligated and in groups of nephrectomized rats receiving rabbit antiserum against erythropoietin before starting the intravenous infusions of T3 and T4. These results indicate that stimulation of marrow erythropoiesis produced by thyroid hormones in our system is not dependent on renal or extra-renal production of erythropoietin. The progressive introduction of T3 and T4 into the circulation of rats with bilateral nephrectomy or ureter-ligated normal rats, may overload the mechanism of transport of these hormones in plasma. As a consequence, a progressive increase in free active forms of T3 and T4 in plasma may occur. Our interpretation of the present findings is that thyroid hormones stimulate directly bone marrow erythropoiesis. This stimulation is clearly evident when high levels of free active forms of thyroid hormones are present in plasma.

Animals↗
PubMed1975

Effects of testosterone on bone marrow erythroid cells of normal and nephrectomized rats.

Continuous infusions of testosterone for 8 hr exerted a stimulatory effect on the bone marrow erythroid compartment of normal rats. However, simultaneous administration of testosterone with antiserum against erythropoietin resulted in a complete inhibition of the erythropoietic effects of testosterone. In addition, the stimulatory action of testosterone on bone marrow erythroid cells was completely abolished in rats with bilateral nephrectomy. These results suggest that testosterone stimulates erythropoiesis indirectly, through a previous stimulation of kidney erythropoietin production.

Animals↗