Potassium homeostasis in chronic experimental diabetes mellitus in rats

1984 ◽  
Vol 105 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Matsuhiko Hayashi ◽  
Shigetoshi Senba ◽  
Ikuo Saito ◽  
Waichi Kitajima ◽  
Takao Saruta

Abstract. To examine potassium homeostasis in diabetes mellitus, we observed the effect of dietary potassium loading on the renin-angiotensin-aldosterone system and potassium balance in streptozotocin-induced diabetic rats. In diabetic rats with 26.51 ± 1.89 mmol/l of serum glucose, the plasma renin activity (PRA), plasma aldosterone (PA), immunoreactive insulin (IRI) and urinary excretion of prostaglandin E2 (PGE2) were all significantly lower than in control rats, but the plasma potassium and renal function were not significantly different. With potassium loading, both control and diabetic rats showed a similar increase in plasma potassium and urinary potassium excretion and a decrease in PRA, but the IRI, plasma corticosterone and urinary excretion of PGE2 exhibited no significant change. On the other hand, the PA was significantly increased only in the control rats, and not in the diabetic rats on potassium loading. Based up on these results, it is suggested that potassium homeostasis is well maintained in diabetic rats with normal renal function in spite of an attenuated response of aldosterone secretion to dietary potassium loading and insulin deficiency.

Author(s):  
Р.И. Айзман ◽  
А.П. Козлова ◽  
Е.И. Гордеева ◽  
М.С. Головин ◽  
Г.А. Корощенко ◽  
...  

Цель - исследование влияния куркумы длинной и галеги восточной на осмо- и ионорегулирующую функции почек крыс при аллоксан-индуцированном сахарном диабете и острой почечной недостаточности в эксперименте. Методика. Эксперименты выполнены на самцах крыс Wistar (n=70) с моделью сахарного диабета (1-я серия) и острой почечной недостаточности (2-я серия). В обеих сериях животные были поделены на 3 группы: крыс 1-й группы содержали на стандартном корме, крысам остальных групп в корм добавляли куркуму (2-я группа) или галегу (3-я группа) (2% от массы корма). На 7-е сут эксперимента проводили исследование диуретической и ионоуретической функций почек натощак и после 5% водной нагрузки. Концентрацию ионов в моче и плазме определяли методом пламенной фотометрии; осмотическую концентрацию биологических жидкостей - методом криоскопии; биохимические показатели крови - колориметрическим методом. Результаты. У животных с сахарным диабетом фоновый диурез, а также экскреция натрия и калия были статистически значимо выше, чем у контрольных животных. При острой почечной недостаточности наблюдался более низкий уровень диуреза и ионоуреза, особенно после водной нагрузки. Прием куркумы и галеги вызывал улучшение осмо- и ионорегулирующей функции почек у крыс с сахарным диабетом, и практически не влиял на эти функции почек при острой почечной недостаточности. Заключение. При сахарном диабете оба фитопрепарата вызывали понижение концентрации глюкозы, креатинина, мочевины и улучшение ионно-осмотических показателей плазмы крови, при этом эффект куркумы был выражен отчетливее. При острой почечной недостаточности эти фитопрепараты не давали описанного эффекта. Aim. To study effects of the phytomedicines, Curcuma longa and Galega orientalis, on osmosis- and ion-regulating renal functions in rats with experimental diabetes mellitus (DM) and acute renal failure (ARF). Methods. Experiments were performed in two series on Wistar male rats (n=70) with modeled diabetes mellitus (series 1) and acute renal failure (series 2). In each series, the animals were divided into 3 groups, 1) rats of group 1 receiving a standard diet; 2) rats of groups 2 and 3 receiving a standard diet supplemented with turmeric or galega (2% of food weight), respectively. On the 7th day of the experiment, the diuretic and ionuretic renal function was studied in fasting state and after 5% water loading. Concentrations of ions in urine and plasma were determined by flame photometry; osmotic concentrations of biological fluids were measured by cryoscopy; blood biochemical parameters were measured by colorimetry. Results. In diabetic rats, background diuresis and sodium and potassium excretion were significantly higher than in the control animals. In rats with acute renal failure, diuresis and ionuresis were significantly lower, particularly after the water loading. Turmeric and galega supplementation improved the osmotic and ion-regulating renal function in diabetic rats and left practically unchanged these functions in rats with acute renal failure. Conclusion. In rats with diabetes mellitus, both herbal remedies reduced concentrations of glucose, creatinine, and urea and improved ion-osmotic parameters of blood plasma with a more pronounced effect of turmeric. In acute renal failure, these phytomedicines did not produce the described effects.


PEDIATRICS ◽  
1984 ◽  
Vol 74 (2) ◽  
pp. 259-264
Author(s):  
William D. Engle ◽  
Billy S. Arant

The possibility that negative potassium balance may occur in critically ill preterm neonates is suggested by factors such as the usual provision of minimal potassium intake, increased plasma aldosterone concentrations, increased prostaglandin synthesis, and the frequent use of diuretic agents. In order to assess the relationship between potassium balance and renal prostaglandins, nine infants with respiratory distress syndrome (mean birth weight 1,264 g, mean gestational age 30.6 weeks) were studied sequentially with timed-urine collections during the first four postnatal days and values were compared with those of 18 preterm infants without respiratory distress syndrome. Mean plasma potassium concentrations decreased significantly from 4.87 ± 0.19 mEq/L (mean ± SEM) on day 1 to 3.83 ± 0.18 mEq/L on day 4, (P < 0.05), and cumulative potassium balance was -4.07 ± 0.95 mEq/kg or 10% of estimated total body potassium. Urinary excretion of prostaglandin E, on day 1 in infants with respiratory distress syndrome was significantly greater than in those without respiratory distress syndrome (22.0 ± 4.9 v 8.3 ± 1.6 ng/mg of creatinine) and varied directly with urinary potassium excretion (r = .66, P < .001). These studies suggest that consideration be given to the importance of providing sufficient potassium to prevent hypokalemia in the stressed preterm infant and that pharmacologic agents that alter prostaglandins or potassium excretion should be used with caution.


1983 ◽  
Vol 244 (1) ◽  
pp. F28-F34 ◽  
Author(s):  
D. B. Young ◽  
A. W. Paulsen

The interacting effects of aldosterone and plasma potassium concentration on steady-state renal potassium excretion were studied in two groups of chronically adrenalectomized dogs. In group I (six dogs, 22.9 kg) aldosterone was infused intravenously at 20 micrograms/day while potassium intake was changed in steps of 7-10 days duration from 10 to 30 to 100 meq/day. At the completion of each step, plasma potassium concentration, urinary potassium excretion, and other variables that potentially may affect renal function were measured. In group II (six dogs, 22.2 kg) a similar protocol was followed except that aldosterone was infused at 250 micrograms/day and the potassium intake levels were 30, 100, and 200 meq/day. Plasma potassium concentration and excretion data for the 20 micrograms/day group were: 3.22 +/- 0.26 meq/liter and 5 +/- 1 meq/day, 4.35 +/- 0.08 meq/liter and 21 +/- 2 meq/day, and 5.88 meq/liter and 82 +/- 3 meq/day at the 10, 30, and 100 meq/day intake levels, respectively. For the 250 micrograms/day group the values were: 2.72 +/- 0.18 meq/liter and 28 +/- 7 meq/day, 4.16 +/- 0.14 meq/liter and 71 +/- 8 meq/day, and 4.40 +/- 0.14 meq/liter and 172 +/- 26 meq/day at the 30, 100, and 200 meq/day intake levels. Therefore, the increase in aldosterone infusion rate shifted the relationship between plasma potassium concentration and potassium excretion to the left so that at a given level of plasma potassium a greater amount of potassium was excreted. In the normal range of plasma potassium concentration (4.00-4.40 meq/liter) the increase in aldosterone levels resulted in a four- to eightfold increase in daily potassium excretion.


1984 ◽  
Vol 66 (2) ◽  
pp. 129-140 ◽  
Author(s):  
K. E. Milmer ◽  
T. Bennett ◽  
S. M. Gardiner

1. Adrenal regeneration hypertension was induced in male Wistar rats by unilateral adrenal enucleation, contralateral adrenalectomy and the provision of a 1% (w/v) NaCl solution for drinking. 2. A fivefold increase in dietary KCl content caused a significant reduction in the systolic blood pressure of hypertensive rats but not of control rats. 3. During the increase in potassium intake there was a marked polydipsia. When 1% NaCl solution was the drinking fluid, the resultant increase in sodium intake was associated with an abolition of the antihypertensive effect of potassium loading, but when the sodium intake was held constant, the antihypertensive effect was maintained. 4. In rats with adrenal regeneration hypertension, plasma volume was significantly higher, and packed cell volume and plasma protein concentrations were significantly lower than in control rats. These differences were abolished after 4 days of dietary KCl supplementation. 5. Increased dietary potassium intake was associated with significantly lower serum aldosterone concentrations and significantly higher plasma potassium concentrations in adrenal enucleated rats compared with controls. 6. The possibility that a reduction in extracellular fluid volume (due to a natriuresis) and/or a peripheral vasodilatation contributed to the antihypertensive effect of KCl loading is discussed.


1987 ◽  
Vol 252 (1) ◽  
pp. E68-E76 ◽  
Author(s):  
P. Castellino ◽  
D. C. Simonson ◽  
R. A. DeFronzo

The effect of acute and chronic beta- and alpha-adrenergic blockade on potassium homeostasis during moderate intensity exercise (40% VO2max) was investigated in control and insulin-dependent diabetic subjects. In protocol I, subjects were studied during exercise alone, exercise plus intravenous propranolol, and exercise plus intravenous phentolamine. In both the control and diabetic groups, exercise alone produced a modest increase in the plasma potassium concentration (0.31 +/- 0.06 meq/l), while propranolol exacerbated this hyperkalemic response. In contrast, the increment in plasma potassium during phentolamine was similar to exercise alone in normals but was 26% (P less than 0.05) lower in the diabetic group. In protocol II, the effect of chronic (5 days) beta-adrenergic blockade on potassium homeostasis was examined. Subjects participated in three studies: exercise alone, exercise plus propranolol (beta 1/beta 2-antagonist), and exercise plus metoprolol (beta 1 antagonist). In the nondiabetic group, both propranolol and metoprolol were associated with a 40% greater increase in potassium compared with exercise alone. In the diabetic group, propranolol, but not metoprolol, was associated with a deterioration in potassium tolerance. In no study could the alterations in potassium homeostasis be explained by a change in urinary potassium excretion. In summary, alpha-adrenergic blockade ameliorates exercise-induced hyperkalemia in diabetic but not in control subjects, nonspecific beta-adrenergic blockade causes a greater increment in potassium when compared with exercise alone, and specific beta 1-adrenergic blockade exacerbates exercise-induced hyperkalemia in control, but not in diabetic subjects. These results indicate that both alpha- and beta-adrenergic regulation of extrarenal potassium metabolism is altered in insulin-dependent diabetes mellitus.


2019 ◽  
Vol 6 (13) ◽  
pp. 331-345 ◽  
Author(s):  
Mayane Oliveira Rebouças da Silveira ◽  
Liliany Souza de Brito Amaral ◽  
Samira Itana de Souza ◽  
Halanna Rocha Ferraz ◽  
Jéssica Alves Dias ◽  
...  

This study evaluated the aerobic exercise effects of moderate and progressive intensity on renal function and structure, and oxidative stress in ovariectomized rats with type 1 diabetes mellitus induced by streptozotocin (STZ). Eighteen Wistar rats were divided into 3 groups: OSC - ovariectomized and sedentary control rats; OSD - ovariectomized and sedentary diabetic rats; and OTD - ovariectomized and trained diabetic rats. After induction of diabetes, the OTD group was submitted to eight weeks of exercise. Twenty-four hours after the last training session urine samples were collected. Blood samples and kidneys were collected after euthanasia for renal function analysis, histology, morphometry and oxidative stress. Our results have shown a reduction of the weight gain, increase of kidney weight and postprandial glycemia in diabetic rats. However, exercise decreased glycosuria and prevented the proteinuria in OTD group rats. Focal segmental glomerulosclerosis (FSGS), juxtamedullary glomerular tuft area, tubulointerstitial lesions (TIL), brush border loss and tubular cell debridement were reduced in OTD rats. In addition, exercise training decreased urinary and plasma concentrations of thiobarbituric acid reactive substance (TBARS). Our results demonstrate the beneficial effect of progressive aerobic exercise on proteinuria, glycosuria, and renal structure in ovariectomized diabetic rats, which may be mediated in part by reduction of oxidative stress.


1995 ◽  
Vol 88 (4) ◽  
pp. 413-419 ◽  
Author(s):  
Yasunobu Hirata ◽  
Yasuko Suzuki ◽  
Hiroshi Hayakawa ◽  
Etsu Suzuki ◽  
Kenjiro Kimura ◽  
...  

1. In order to determine whether atrial natriuretic peptide might play a role in the development of glomerular hyperfiltration in diabetes mellitus, we examined the effects of administration of glucose, albumin, atrial natriuretic peptide and an atrial natriuretic peptide receptor antagonist on renal function in rats with streptozotocin-induced diabetes mellitus and vehicle-treated control rats. 2. Four weeks after treatment, rats with diabetes mellitus had a higher mean plasma atrial natriuretic peptide concentration than controls [152 ± 5 (SE) versus 115 ± 6 pg/ml, P < 0.01] and a higher glomerular filtration rate (3.3 ± 0.1 versus 2.7 ± 0.2 ml min−1 kg−1, P < 0.05). 3. Infusion of albumin or glucose caused significant increases in atrial pressure, plasma atrial natriuretic peptide concentration and urinary excretion of sodium and protein in both groups of rats. 4. Increasing plasma atrial natriuretic peptide concentration by 60% via atrial natriuretic peptide infusion increased urinary excretion of sodium and protein in both control rats and rats with diabetic mellitus. 5. Administration of the atrial natriuretic peptide receptor antagonist HS-142-1 to diabetic rats resulted in diminished urinary excretion of both sodium (−61 ± 14%, P < 0.02) and protein (−51 ± 17%, P < 0.05). These changes were associated with a significant reduction in glomerular filtration rate (−32 ± 11%, P < 0.05) and urinary cGMP excretion (−40 ± 14%, P < 0.05). No significant effects of HS-42-1 on renal function were observed in control rats. 6. These results suggest that elevated plasma glucose may lead to an increase in atrial natriuretic peptide secretion via a rise in atrial pressure, which in turn results in increased urinary sodium and protein excretion. Elevated plasma atrial natriuretic peptide appears to contribute to the proteinuria in diabetic rats.


1985 ◽  
Vol 68 (5) ◽  
pp. 601-604 ◽  
Author(s):  
A. Barden ◽  
L. J. Beilin ◽  
R. Vandongen ◽  
I. Rouse

1. Measurement of urinary 6-ketoprostaglandin (PG) F1α and PGE2 excretion in 83 healthy children, aged 5-15 years, revealed that supervised 4 h urine collections under mild water diuresis provided more consistent results than overnight 12 h urine collections. 2. Males had higher urinary excretion of 6-keto-PGF1α but not of PGE2 compared with females. 3. Urinary potassium was related to 6-keto-PGF1α in both 4 and 12 h urine collections and urinary sodium to 6-keto-PGFα in 4 h collections only. 4. In the sexes combined multiple regression analyses revealed age as the only significant influence on prostanoid excretion (P = 0.001). 5. Thus age and sex and dietary potassium intake need to be considered in studies of urinary prostanoids in children.


1985 ◽  
Vol 248 (3) ◽  
pp. F382-F388 ◽  
Author(s):  
A. Nasjletti ◽  
A. Erman ◽  
L. M. Cagen ◽  
D. P. Brooks ◽  
J. T. Crofton ◽  
...  

This study was designed to investigate relationships between dietary potassium and the renal prostaglandin system in rats. The potassium content of the diet was 0.162 mmol/g during the control period and 0.004, 0.162, 1.351, or 2.702 mmol/g during the experimental period. Relative to control data in rats fed a 0.162 mmol/g potassium diet, the urinary excretion of 6-keto-PGF1 alpha was not affected by high potassium intake but increased (P less than 0.05) by 25% in rats fed a low potassium diet for 13 days and was associated with reduction of plasma potassium and with elevation of both plasma renin and net release of 6-keto-PGF1 alpha from renal inner medulla slices incubated in Krebs solution. The excretion of PGF2 alpha was not affected by low potassium intake but increased (P less than 0.05) by about twofold in rats fed a potassium-rich diet (1.351 and 2.702 mmol/g) for 13 days and was associated with elevation of plasma potassium concentration, renal prostaglandin 9-keto-reductase activity, and urinary excretion of kallikrein and vasopressin. The urinary excretion of PGE2 was not altered in rats fed either low or high potassium diets. Altogether, these results indicate selective influence of dietary potassium on the urinary excretion of prostaglandins in the rat.


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