Effects of erythropoietin administration on prolactin secretion in normal subjects.

To evaluate the acute effect of human erythropoietin (r-HuEPO) on basal and stimulated prolactin (PRL) secretion, 18 normal subjects (12 females, 6 males) were studied. The PRL response to thyrotropin-releasing hormone (TRH; 200 micrograms intravenously, n = 7), metoclopramide (MCP, 20 mg intravenously, n = 5) and fenfluramine (FF, 60 mg os, n = 6) was tested in presence of saline or r-HuEPO (30 U/kg intravenously). The drug neither modified basal PRL levels nor affected the normal PRL release to TRH, MCP and FF. Our results indicate that, in normal subjects, the acute administration of therapeutic doses of r-HuEPO does not interfere with PRL secretion both after a direct pituitary stimulus and after stimuli involving dopaminergic and serotoninergic pathways.

Low protein supplemented diet corrects altered serum thyroid hormone and TSH concentrations in patients with chronic nephrotic syndrome.

Creatinine clearance, daily urinary protein excretion, serum concentrations of thyroid hormones (TT4, TT3, fT4, fT3), TSH and parathyroid hormone (PTH), have been measured before and after 2 or 6 months of a low protein diet supplemented with aminoacids and ketoanalogues in 18 patients affected by chronic nephrotic syndrome without significant impairment of renal function. Mean creatinine clearance and mean serum protein concentration (79.5 +/- 13.8 ml/min and 5.4 +/- 0.6 g/dl, mean +/- S.D., respectively) did not significantly change (79.1 +/- 17.3 ml/min and 5.5 +/- 0.6 g/dl) after the diet. Mean daily urinary protein excretion (7.1 +/- 2.2 g/day basally) significantly decreased (5.5 +/- 1.9 g/day) after the diet (p less than 0.05). Mean serum TT4 concentration (5.6 +/- 1.8 micrograms/dl basally) significantly increased (6.7 +/- 2 micrograms/dl, p less than 0.05) after the diet. Mean serum TT3 concentration (106.7 +/- 28.5 ng/dl, basally) significantly increased (126.7 +/- 22.6 ng/dl) after the diet (p less than 0.01). Mean serum fT4 and fT3 concentrations (8.0 +/- 2.9 pg/ml and 4.5 +/- 1.6 pg/ml, respectively) did not significantly change (9.4 +/- 2.7 pg/ml, and 4.9 +/- 1.9 pg/ml, respectively) after the diet. In some patients low basal serum concentration values of TT4, TT3, fT4, fT3 became normal after the diet. Mean serum TSH concentration (3.1 +/- 2.3 microU/ml basally), significantly decreased (1.5 +/- 1.3 microU/ml) after the diet (p less than 0.05). Mean serum PTH concentration (0.7 +/- 0.3 ng/ml basally) significantly decreased (0.4 +/- 0.2 ng/ml) after the diet (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Vegan supplemented diet in nephrotic syndrome.

Thirteen patients (7 males, 6 females, aged 17-68 years) affected by primary, steroid-resistant, nephrotic syndrome and normal renal function were treated with a vegan, low-protein (0.7 g/kg per day) diet supplemented with essential amino acids and Ketoanalogues (VSD) for 3.9 +/- 2.9 months. These patients were studied at the beginning (following an unrestricted protein diet (UPD) supplying about 1 g/kg per day of mixed proteins) and at the end of VSD period. Urinary protein excretion decreased from 8.7 +/- 2.6 to 5.6 +/- 2.4 g/day (P less than 0.01), serum total cholesterol from 334.6 +/- 97.1 to 275.6 +/- 49.4 mg/dl (P less than 0.05). Serum albumin, HDL-cholesterol, triglycerides, and anthropometric measurements (triceps skinfold thickness and middle arm muscle circumference) did not change. Urinary urea nitrogen decreased from 7.5 +/- 1.8 to 3.8 +/- 1.2 g/day (P less than 0.005), according to dietary prescriptions. Creatinine clearance changed from 104.4 +/- 28.7 to 89.3 +/- 16.7 ml/min (n.s.) and no correlation was found with the changes in urinary protein excretion. This data suggest that VSD reduces proteinuria and exerts favourable effects on hypercholesterolaemia. Protein malnutrition was absent in these patients, probably because of the essential amino acids and ketoanalogues supplementation.

Effects of a low-phosphorus, low-nitrogen diet supplemented with essential amino acids and ketoanalogues on serum beta-endorphin in chronic renal failure.

The effects of a vegetarian low-protein, low-phosphorus diet supplemented with essential amino acids and ketoanalogues, on the serum beta-endorphin, growth hormone, parathyroid hormone, thyroid hormones (T3 and T4), pituitary TSH and total cortisol were studied in 12 male chronic uremics. beta-Endorphin decreased, as well as growth hormone. Parathyroid hormone and T3 improved significantly, reaching almost normal values. It is hypothesized that the correction of the beta-endorphin excess may account in part for the improvement of some endocrinological and metabolic effects exerted by this dietary treatment. The possible pathophysiological mechanisms which could explain the antiendorphinic action of this treatment in uremic patients are discussed, as well as the possible beneficial endocrine and metabolic effects exerted by the fall in circulating beta-endorphin.

Nutritional treatment of renal failure in type 1 diabetic nephropathy.

This study reports the effects of a low-protein, low-phosphorus, supplemented diet in 8 type 1 diabetics with renal failure. The rate of decline of creatinine clearance, the changes of the urinary protein loss, of total serum protein, of the daily insulin requirement, of the nutritional status and of some hormonal derangements were examined. The rate of decline of creatinine clearance decreased from 1.38 +/- 0.27 ml/min/month during a previous 15.9-month period of unrestricted protein diet, to 0.03 +/- 0.37 ml/min/month during the 17.4 months on supplemented diet. Urinary protein loss significantly decreased, and total serum protein increased. The daily insulin requirement decreased and no deterioration of the nutritional status occurred. Secondary hyperparathyroidism was partially reversed and the mild hypothyroidism corrected. A restricted protein and phosphorus diet supplemented with essential amino acids and ketoanalogs seems to exert several beneficial and no unwanted side effects in type 1 diabetics with renal failure.

Protection of renal function and of nutritional status in uremic rats by means of a low-protein, low-phosphorus supplemented diet.

A low-protein, low-phosphorus diet supplemented with essential amino acids and keto analogues was given to 12 rats, starting from the 90th day after subtotal nephrectomy. The purpose was to assess its effect on the residual renal function and on the nutritional status in rats with already established severe renal failure. Ten control rats in the same conditions, following a standard diet supplying normal amounts of protein and phosphorus were also studied. The supplemented diet exerted a well-evident protection of residual renal function and structure: lower rate of decline of creatinine clearance, lower mortality, significant decrease of proteinuria and almost total absence of histological signs of activity. The nutritional status was also well protected by the dietary therapy: increase of body weight, normal values of total serum protein, and low-constant values of urea appearance. In the control rats body weight decreased, total serum protein was lower than normal and the values of urea appearance were increasing simultaneously with a decreasing food intake and body weight.

Effects of a low-phosphorus, low-protein diet supplemented with essential amino acids and keto analogues on 'overt' diabetic nephropathy.

In this paper we studied the effects of a low-protein, low-phosphorus supplemented diet in 8 type I diabetics with 'overt' diabetic nephropathy and mild or severe renal insufficiency. We examined the following parameters: the rate of decline of creatinine clearance, the urinary protein loss, the total serum protein, the daily insulin requirement, the serum fasting glucose, the pattern of serum lipids (serum total cholesterol, HDL cholesterol and serum triglycerides), the mean blood pressure and body weight. The rate of decline of creatinine clearance decreased monthly from 1.48 +/- 0.20 ml/min during a previous 15.6-month period of unrestricted protein diet (UPD), to 0.13 +/- 0.3 ml/min during the 11.4 months on the supplemented diet (SD). The mean blood pressure did not differ during UPD (130.9 +/- 7.0 mmHg) and during SD (128.1 +/- 1.6 mmHg). Urinary protein loss significantly decreased on SD, and total serum protein increased. The daily insulin requirement and the serum fasting glucose levels significantly decreased on SD. Serum cholesterol was lower during SD than during UPD, while serum HDL cholesterol and serum triglycerides were not significantly modified. In some patients the body weight decreased on SD as a consequence of the disappearance of edema. In conclusion, on the basis of these preliminary observations, the SD slows the progression of renal failure and seems to exert several beneficial and no unwanted side-effects in renal failure of type I diabetics.

Combined therapy for selected chronic uremic patients: infrequent hemodialysis and nutritional management.

The results are described of a combined nutritional (supplemented diet) and dialytic (once a week hemodialysis) therapy, employed in 17 selected chronic uremics for a mean period of 18.2 months/patient. The clinical findings, blood chemical abnormalities and changes of renal function were examined and compared with those of patients on the standard thrice-a-week dialysis schedule and free diet. The clinical findings were not significantly different in the two groups. The residual renal function of patients on combined therapy declined faster than in patients on conservative treatment, but at a slower rate than in those on thrice-a-week dialysis. The time averages of serum urea, methylguanidine and phosphate concentrations and their postdialytic rebounds were lower in the patients on combined therapy than in those on thrice-a-week dialysis, whereas the time averages of the serum creatinine concentration were higher, and those of serum bicarbonate and serum oxalate were not significantly different in the two groups. It is concluded that this combined therapy is a valid alternative to the conventional thrice-a-week hemodialysis and free diet for selected patients and for periods of time whose duration is conditioned by the rate of decline of the residual renal function.

Parathyroid function and pituitary-gonadal axis in male uremics; effects of dietary treatment and of maintenance hemodialysis.

Parathyroid and pituitary-gonadal secretions were studied in 18 male uremics following a low protein diet supplemented with essential amino acids and ketoanalogues (SD), and in 8 subjects on maintenance hemodialysis (MHD). SD corrected high serum PTH and low serum testosterone (sT) levels, while pituitary hormones (LH, FSH, PRL) were elevated and did not change. Patients on MHD had very high siPTH, PRL and LH levels, while sT was markedly low. These data suggest that PTH is a prominent cause of sexual dysfunction in male uremics, since SD can restore sT secretion by correcting PTH levels, without improving pituitary dysfunctions. In dialyzed patients secondary hyperparathyroidism worsens and is an important cause of low sT secretion, but also a severe hyperprolactinemia develops, which may further impair gonadal function.