Increased urinary C-peptide and albumin excretion in juvenile borderline hypertensives.

The study was designed to evaluate the urinary excretion of C-peptide and albumin, and urinary N-acetyl-beta-D-glucosaminidase (NAG) activity in juvenile borderline hypertensives. The second aim was to examine the relationship between these variables and ambulatory blood pressure level and variability. The study group consisted of 21 non-obese males consecutively chosen from patients with borderline hypertension, defined by sphygmanometer readings, examined in our outpatient clinic. All subjects collected separately their day-time and night-time urines during the period of ambulatory blood pressure monitoring. In 16 patients, who were considered to have "sustained" borderline hypertension, both 24-h urinary C-peptide excretion and 24-h UAE were significantly increased in comparison to those of the controls, while NAG activity did not differ significantly between the two groups. UAE was significantly lower at night than during the day in both borderline hypertensives and controls. Twenty-four-hour UAE in borderline hypertensives correlated significantly with the ambulatory blood pressure variability, but not with the average blood pressure level. These results suggest that the 24-h insulin secretion rate estimated by means of urinary C-peptide excretion is significantly increased in "sustained" borderline hypertensives. Elevated UAE in juvenile borderline hypertensives can be explained by a possible direct effect of systemic blood pressure variability on albuminuria.

[Transplantation of free beta islet cells as a method leading to normalization of glucose tolerance in rats with experimental diabetes]. / Transplantacja wolnych komórek beta wysp trzustki jako metoda wyrównania zaburzen tolerancji glukozy u szczurów z cukrzyca doswiadczalna.

The aim of present study was to investigate the effect of free beta cells transplantation on carbohydrate tolerance in rats with streptozotocin-induced diabetes. Free beta cells were isolated by mechanical disruption of isolated pancreatic islets in Ca and Mg free medium. 1500 and 3000 isolated islets were used for the isolation of 500 x 10(3)-1.099 x 10(3) and 1.398 x 10(3)-2.098 x 10(3) free cells, respectively. Between 78% and 98% of all isolated cells were the variable cells. After isogenic transplantation of free beta cells, blood glucose concentration in all animals was normalized within 14 days. The rate of glycemia normalization was related to the amount of viable free cells. The glucose assimilation coefficient after intravenous glucose administration in normal rats, diabetic rats and diabetic rats after transplantation of free cells was: 2.98 x 10(-2); 0.68 x 10(-2) and 2.04 x 10(-2) mg/dl/min, respectively. Allogenic transplantation of free beta cells caused only a transient decrease in blood glucose level.

Protective effect of allopurinol, alpha-tocopherol and chlorpromazine on rat pancreatic islets stored prior to transplantation.

Iso-transplantation of 800 isolated rat pancreatic islets into the portal vein of diabetic rats was performed. Isolated islets were kept in Hanks buffer for 12 hours prior to transplantation. Part of donors was pretreated with allopurinol, alpha-tocopherol and chlorpromazine. Transplantation of islets isolated from nonpretreated rats did not cause any significant changes in plasma glucose concentration of recipients, while transplantation of islets isolated from donors after pretreatment with the tested substances brought glucose level back to normal 3 days after transplantation. Our results indicate that the combination of free radical scavengers, antioxidants and membrane stabilizing drugs may be used to increase the effectiveness of islet transplantation in humans.