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Patients with chronic renal failure often have low plasma zinc (Zn) levels. Some factors that may account for abnormal Zn metabolism in these patients are low dietary Zn intake, a specific Zn transport defect, or absence of intestinal Zn ligand. In this study Zn supplementation and a Zn-chelating drug, diiodohydroxyquinolein (DQ), were used to assess the effects of Zn intake and Zn transporters on Zn plasma levels in patients with chronic renal failure. To meet this objective, 20 uremic patients were randomly assigned to one of the following groups of treatment: group 1 received placebo; group 2 Zn sulfate (100 mg/day p.o.), group 3 DQ (80 mg/day p.o.), and group 4 received Zn sulfate plus DQ at the same dosages as in groups 2 and 3. The Zn plasma levels were measured in venous samples, before and after 1 and 2 weeks of treatment, by atomic absorption spectrophotometry. The Zn plasma levels increased in group 2 patients from 8 +/- 0.2 to 10 +/- 0.4 and 11 +/- 0.9 mumol/l by the end of the 1st and 2nd weeks of treatment, respectively. In group 4 patients, the Zn plasma levels increased even more: from 9 +/- 0.1 to 14 +/- 1.6 and 13 +/- 2.1 mumol/l respectively. The plasma Zn concentration of group 1 and 3 patients remained at basal levels. These results show that DQ, when given along with Zn sulfate supplements, causes a greater increase in plasma Zn levels than that caused by either drug given alone.

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In order to evaluate the effect of zinc (Zn) deficiency on thyroid abnormalities in chronic renal failure, a Zn supplement (100 mg/day, p.o.) was given for four weeks to eight uremic patients under peritoneal dialysis. Zn supplementation increased plasma levels of TSH (5.8 +/- 0.7 to 7.4 +/- 0.7 mU/l, p < 0.02), T4 (61.6 +/- 3.9 to 93.9 +/- 6.2 nmol/l, p < 0.01), T3 (1.31 +/- 0.14 to 1.70 +/- 0.18 nmol/l, p < 0.01) and Zn (7.23 +/- 0.45 to 12.27 +/- 0.76 mumol/l, p < 0.01). A close correlation was found between changes in plasma levels of Zn and changes in TSH (r = 0.82), T4 (r = 0.55) and T3 (r = 0.64), suggesting that Zn deficiency may play a role in the biosynthesis or release of hormones of the hypothalamic-pituitary-thyroid axis in chronic renal failure.

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The plasma levels of androstenedione (A), testosterone (T), dihydrotestosterone (DHT), follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) were studied in 15 men (aged 24-50 years) with chronic renal failure under periodic peritoneal dialysis, before and after 50 mg of elemental zinc (Zn) orally, twice a day for three weeks. Before treatment, they were divided into three groups: group I, plasma A above normal and PRL less than 100 ng/ml; group II, low or normal A levels with PRL less than 100 ng/ml; and group III, normal or high A levels with PRL greater than 100 ng/ml. After oral Zn, plasma FSH, LH, and PRL were unchanged in all groups; however, in groups I and II plasma A was within normal T and DHT rose significantly, the A/(T+DHT) ratio decreased to normal, and the T/DHT ratio rose above normal. In group III plasma androgens remained low and androgen ratios were unchanged. Oral Zn seems to improve the conversion of A to T and also uncovered the possibility that plasma PRL levels greater than 100 ng/ml might cause a blockade in the 5 alfa-reductase.

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Plasma zinc (Zn), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and androgens concentrations were determined in 15 male patients with chronic renal failure who were successful recipients of kidney transplant. After 25 +/- 8.5 months of the renal transplant, Zn levels were (88 +/- 4 g/dl) lower than in the control group (116 +/- 5 micrograms/dl). Normal concentrations for androstenedione (A) (0.63 +/- 0.05 ng/ml) and testosterone (T) (3.31 +/- 0.15 ng/ml) were found. Dihydrotestosterone (DHT) levels (0.38 +/- 0.01 ng/ml) were lower than normal (1.11 +/- 0.09 ng/ml), suggesting a blockade in the conversion of T to DHT. Eleven of the 15 patients showed higher PRL levels (9.5 +/- 0.8 ng/ml) in contrast with the normal group (3.6 +/- 0.3 ng/ml). Ten patients received orally 2-alpha-bromoergocriptine (BEC) 2.5 mg/day for ten days. Plasma PRL decreased to 2.6 +/- 1.0 ng/ml (p less than 0.001), but A and T levels did not significantly change; however, DHT increased from 0.38 +/- 0.02 ng/ml to 0.72 +/- 0.04 ng/ml (p less than 0.01). All patients showed an increase in both gonadotropins before BEC without significant changes after treatment. The high PRL levels may be responsible for the impaired conversion of T to DHT, possibly by interference with the enzyme 5 alpha-reductase.

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This study correlates plasma levels of Zinc (Zn) and some pituitary and testicular hormones in 20 uremic men (aged 17-58 years) on a weekly peritoneal dialysis program. Patients were compared to 12 healthy male volunteers (aged 28-40 years). In uremic men, plasma androstenedione (A) was elevated, while testosterone (T), dihydrotestosterone (DHT), and Zn were low. On a group basis, plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) were normal while prolactin was increased. A negative correlation was observed between plasma A and LH levels, as well as between the A/T+DHT ratio and plasma Zn concentrations. Our results suggest a diminished A-to-T conversion and point to the possible role of Zn in the enzyme activity of the 17 beta-hydroxysteroid dehydrogenase.

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Several techniques are used to detect rejection episodes in renal transplants; complexity renders these tests impractical for clinical use in most cases. This paper reports the results obtained in the study of urinary FDP, by counterimmunoelectrophoresis, in 50 healthy subjects and in 360 consecutive samples from 18 renal transplant recipients; urine specimens were examined daily for periods of time of up to 60 days post transplant. Endogenous creatinine clearance levels were also quantified. Our findings show that while in normal subjects negative tests were always obtained in kidney transplant patients, increased FDP excretion was found, with peak levels observed at least 24 hours before the decrease of glomerular filtration rates and clinical manifestations of acute rejection which subside with immunosuppression. Finally, urinary FDP excretion in the oliguric phase of post transplant acute renal failure was similar to that of patients where kidney transplants functioned without any evidence of rejection.

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To study some of the aspects of albumin homeostasis and proteinuria in PNS, the hepatic production of albumin is analyzed using semiquantitative immunofluorescent techniques, in biopsy specimens from nine subjects, free of hepatic or renal disease and nine patients with PNS, where renal biopsies were also made. Tissue sections 0.5 millimicron thick were cut. The hepatic synthesis of albumin, interpreted by the number of cells with specific fluorescence, was much higher in patients with PNS (p less than 0.001), and kept inverse relationship with serum albumin concentrations. Numberless droplets containing albumin were observed in the renal tissue indicating intense resorption and catabolism in the luminal and basal portions of the proximal convoluted tubules. Our findings indicate that, in PNS, albumin synthesis is substantially increased and hypoalbuminemia is caused by exaggerated renal excretion and catabolism.

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Six cases of membranoproliferative glomerulonephritis with dense deposits are reported. This entity has clinical, immunological and morphological characteristics which make it a variant of the membranoproliferative glomerulonephritis: a very frequent disease among our population.

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Phagocytosis was evaluated in nine patients with splenctomy undergoing renal transplant, eight renal transplanted patients without splenectomy, three immunodepressed patients with terminal renal failure, four patients with splenectomy and six healthy volunteers. For phagocytosis evaluation, neutrophils adhered to glass were used. They were cover with 4% latex and albumin containing culture medium with or without phagocytosis stimulating tetrapeptide extracted from IgG in each case. Phagocytosis was decreased in all groups studied. Immunodepressed patients showed the highest diminishment of phagocytosis and patients with splenectomy and immunodepression the lesser. It was speculated that such a finding is due to a decrease of tetrapeptide in serum.

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