Search PubMed⌕ Search

Biomedical subjects

K Olgaard

Publications and source records attributed to K Olgaard.

At least 73 records · Page 4Linked to original sources
PubMed1981

Suppressive effect of 1,25-dihydroxyvitamin D3 on circulating parathyroid hormone in acute renal failure.

To elucidate whether the kidney hormone 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3) directly feedback regulates the secretion of parathyroid hormone (PTH), 10 patients with acute oliguric renal failure were studied. Serum ionized calcium (Ca++) was kept constant and subnormal by continuous peritoneal dialysis with low Ca++ dialysis fluid. In the control period (24 h), PTH was found to be constantly increased. In the treatment period (30 h), five patients received 250 ng 1,25-(OH)2D3 iv every 6 h, while five comparable patients served as controls. A significant suppression of PTH-levels was observed in the treatment group after a lag-period of 12-18 h during stable low Ca++. In the control group, PTH remained constantly increased throughout the trial. Since Ca++ was kept constant by the dialysis procedure, the observed reduction of PTH-levels cannot be explained by the calcemic effect of 1,25-(OH)2D3. The data suggest that 1,25-(OH)2D3 directly feedback regulates PTH secretion in humans with normal parathyroid glands.

Acute Kidney Injury↗
PubMed1981

Two cases of 17 alpha-hydroxylase deficiency--one combined with complete gonadal agenesis.

Two cases of 17 alpha-hydroxylase deficiency are described. Both patients had primary amenorrhoea, total lack of female secondary sexual characteristics, slight hypertension and hypokalaemia. One patient was of male genotype (male pseudohermaphrodite), and in addition this patient had complete gonadal agenesis. The other patient was of female genotype. In both patients the level of plasma corticosterone was markedly increased, whereas the concentration of plasma cortisol was very low and plasma aldosterone low within the normal range. Furthermore, the plasma ACTH level was significantly increased and the plasma renin activity around the lower normal limit. The urinary excretion of corticosterone metabolites was markedly increased, whereas the excretion of both cortisol metabolites and tetrahydroaldosterone was decreased. The patients had no symptoms of glucocorticoid deficiency. Treatment with dexamethasone 0.5 mg daily completely suppressed the abnormal corticosterone production and normalized both blood pressure and serum potassium. In addition, the patient of male genotype has received sequential therapy with oestrogen and gestagen for 3 years, but so far no development of the secondary sexual characteristics has occurred.

17-Ketosteroids↗
PubMed1980

Relationship between plasma osmolality and plasma vasopressin in human subjects.

The relationship between plasma osmolality (pOsm) and plasma vasopressin (pAVP) was studied in 13 human subjects during dehydration. The fit of linear, log-linear, parabolic, and exponential models was tested. For all of the data, the nonlinear models had the best fit. However, when individual differences in either gain or threshold were allowed for, the linear models were better than log-linear models. Finally, analyses were made with individual data points. Linear models had the best fit in half of the subjects, whereas for the others the parabolic model gave the best fit. For those subjects investigated in the low range of the osmoregulatory curve, a linear relationship was found, whereas, for those having the most pronounced increase in pOsm, the most significant improvement was found with the parabolic model. This finding indicates that the relationship is not stable during dehydration in the whole range and that hypovolemia probably can influence the secretion rate and/or metabolic clearance rate and thereby the relationship.

Adolescent↗
PubMed1980

Calcium-stimulated vasopressin secretion in uremic patients: an effect mediated via parathyroid hormone?

The effect of whole blood ionized calcium levels on vasopressin (AVP) secretion has been studied in 12 uremic hemodialysis patients (6 nephrectomized and 6 nonnephrectomized), 6 healthy subjects, and a sprue patient, first while she was hypocalcemic and again after her blood calcium had normalized. Changes in whole blood ionized calcium were induced by calcium infusion (3.15 mg Ca/kg BW h-1). In uremic patients, an increase in plasma AVP took place during infusion, and the changes in AVP were correlated to the changes in whole blood ionized calcium. In normals, no changes in AVP were found. In the sprue patient, an increase in plasma AVP correlated to whole blood ionized calcium was found in the hypocalcemic state, but this could not be demonstrated after treatment. Parathyroid hormone has been shown to facilitate calcium entry into cells, and it is proposed that the pathophysiological effect of calcium on AVP secretion in uremic patients is caused by the elevated parathyroid hormone level found in these patients.

Adult↗
PubMed1980

The inability of angiotensin II infusions to raise plasma vasopressin levels in haemodialysis patients.

Since it has previously been claimed that angiotensin II (AII) stimulates vasopressin (AVP) secretion, the effect of AII-infusions was studied in 1) 6 normals, 2) 5 non-nephrectomized haemodialysis (HD) patients, and 3) 6 nephrectomized HD patients. In dialysis patients the infusion rate was increased step-wise from 2-12 ng AII/kg bw x min-1 and was terminated if diastolic blood pressure (BP) increased more than 20 mmHg. Normals were infused at a constant rate of 4 ng AII/kg bw x min-1. In all the groups significant increments in BP and plasma aldosterone occurred while plasma renin activity decreased. The plasma vasopressin level was unchanged in normals, while in the two groups of dialysis patients a minor decrease was found. The present study has therefore not been able to confirm a stimulating effect of a physiological dose of AII on AVP secretion, and the results in anephric patients indicate that a normal plasma AII concentration is of no importance for the plasma AVP level.

Adult↗
PubMed1980

Direct feed-back regulation of PTH-secretion by 1,25-dihydroxyvitamin D3 in renal failure: a controlled trial.

To elucidate whether the kidney hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) regulates the secretion of parathyroid hormone (PTH) by direct feed-back, 10 patients with acute oliguric tubulo-interstitial nephropathy were investigated. Serum ionised calcium (Ca++) was kept constant and subnormal by continuous peritoneal dialysis with low Ca++ dialysis fluid. In the control period (24h) PTH was found to be constantly increased. In the treatment period (30h) 1,25(OH)2D3 was injected i.v. every 6 hours. A significant suppression of PTH-levels was observed after a lag-period of 12-18h during stable low Ca++. In the control group PTH remained constantly increased throughout the trial. The data suggest that 1,25(OH)2D3 regulates PTH-secretion in humans with normal parathyroid glands by direct feed-back.

Adult↗
PubMed1979

Influence of age on the endocrine-metabolic response to surgery.

The pathogenesis of the increased operative risk in elderly patients is unknown. From a theoretical point of view, a change in endocrine-metabolic response might be involved. In the present study, a battery of hormonal and metabolic variables were measured in eight young and eight elderly healthy males undergoing elective inguinal hernial repair under general anesthesia. Blood was drawn before induction of anesthesia, at skin incision, and one, two, and six hours after skin incision. The findings were: 1) Plasma cortisol increase was significantly higher in elderly than in young controls. 2) Plasma renin level was lower in old age, but renin-aldosterone and electrolyte response patterns were alike in the two groups. 3) Thyroid parameters, in terms of serum T4, serum T3, serum rT3, and T3-resin uptake, responded normally to surgery and showed no age-related differences. 4) The hyperglycemic response was not significantly influenced by age indicating unchanged glycoregulatory mechanisms also verified by determinations of plasma catecholamines, cAMP, and insulin. 5) Blood lymphocyte count was constantly lower in elderly than in young and decreased with time, but the age-related difference was not significant. 6) Blood polymorphonuclear leukocytes showed an increase of the same magnitude in both age groups, although at a significantly slower rate in the elderly. It is concluded that age affects some aspects of the initial endocrine-metabolic response to surgery.

Adult↗
PubMed1979

Epidural analgesia inhibits the renin and aldosterone response to surgery.

Renin activity and aldosterone concentration in plasma and excretion of sodium and potassium in urine were measured during a period of 24 hours in 12 patients undergoing hysterectomy under general anaesthesia or epidural analgesia. Analgesia extended from T4 to S5 and was effective throughout the study. The normal stress-induced increase in plasma renin activity and aldosterone was inhibited by epidural analgesia. Urinary excretion of potassium was significantly lower in the epidural group, but sodium and water retention showed no difference between groups. It is concluded that neurogenic stimuli from the surgical area are important release mechanisms of the renin-aldosterone response to surgery. The results suggest that post-operative sodium retention is caused by factors other than the mineralocorticoid system.

Adult↗
PubMed1979

Fluid and electrolyte absorption and renin-angiotensin-aldosterone axis in patients with severe short-bowel syndrome.

In eight patients who had received long-term parenteral nutrition because of short-bowel syndrome the need for parenteral supply of fluid, sodium, and potassium was estimated by balance studies. Six patients had jejunostomies. In two, most of the colon was preserved. Jejunostomy patients had a huge stool mass (1710--5270 g, median 2530 g/day) with fixed concentrations of sodium (92 +/- 10 mmol/l) and potassium (15 +/- 4 mmol/l). In contrast, two patients with massive small-bowel resection but with more than half of the colon intact showed almost normal sodium absorption and considerably smaller stool mass (170--510 g/day). Despite apparently good health and normal plasma electrolytes, urea, and haematocrit, four of six jejunostomy patients were sodium-depleted with low plasma volume, low sodium excretion in the urine, and increased plasma renin activity and, in the three most severe cases, increased aldosterone. Even in case of sodium depletion the sodium loss from jejunostomy effluents remained high and presumably unaffected by salt-retaining hormones. The study confirms the importance of preservation of part of the colon for maintenance of fluid and electrolyte balance in patients with extensive bowel resection. Jejunostomy patients who are eating normally may need large parenteral saline supply. Assessment of water and electrolyte homeostasis in these patients requires determination of the urinary sodium excretion and is supported by measurements of plasma renin activity and plasma aldosterone concentration.

Adult↗
PubMed1979

Hormonal response to volume depletion in non-nephrectomised patients on regular haemodialysis.

The hormonal response to volume depletion by isolated ultrafiltration has been studied in seven non-nephrectomised haemodialysis patients. The mean reduction in blood volume was 14%, and pulmonary artery wedge pressure reduction averaged 77%. No increments in heart rate were observed in any of the patients. Cardiac output decreased while systemic vascular resistance increased. Mean arterial blood pressure remained stable in all but two patients. Significant increments in plasma vasopressin concentration were only found during hypotensive episodes, while in the whole group no significant increase was found. Both plasma renin activity, plasma aldosterone and plasma cortisol increased significantly during isolated ultrafiltration. The moderate increase in systemic vascular resistance indicates that the peripheral sympathetic nervous system - at least partly - was functioning. It was, however, not correlated with changes in any of the measured hormones. Furthermore the adrenal and cardiac response appeared to be absent.

Aldosterone↗
PubMed1979

Scintigraphic skeletal changes in non-dialyzed patients with advanced renal failure.

Technetium-99m-polyphosphate (Tc-PP) bone scintigraphy was performed in 51 patients with advanced renal failure in order to evaluate the applicability of this method in detection of metabolic bone changes in these patients. The creatinine clearance varied from 2 to 40 ml/min and none of the patients had previously been on dialysis treatment. The scintigrams were graded according to the focal and the generalized abnormal uptake of the tracer in the skeleton. 34 patients showed generalized scintigraphic changes and among these the changes in 18 patients were classified as severe. An inverse correlation was found between the kidney function and the generalized scintigraphic classification. Focal bone changes were found in 11 patients. In order to evaluate the influence of the lack of kidney function on the scintigraphic results, 3 patients with acute oliguric renal failure were examined. All had normal scintigrams. It is concluded that Tc-PP bone scintigraphy is a sensitive method in revealing renal osteodystrophy in non-dialyzed patients with advanced renal failure in agreement with previous reports on patients on chronic hemodialysis and after kidney transplantation.

Adolescent↗