[Plasma erythropoietin levels in kidney transplant patients with impaired function of the renal graft]

In 81 patients with failing kidney transplant, plasma levels of erythropoietin, iron, ferritin and TIBC were assessed. Progression of failure of the excretory function of the kidney transplant was accompanied by decreasing Hb and Ht values but increasing plasma levels of erythropoietin. In all examined patients presence of iron deficiency could be excluded. Results obtained in this study suggest that relative erythropoietin deficiency is the major cause of anaemia in patient with a failing kidney transplant.

[Plasma erythropoietin levels in patients with noninflammatory acute renal failure]

Plasma levels of erythropoietin (EPO) were estimated in 14 patients with noninflammatory acute renal failure during the oliguric anuric and polyuric phase respectively. During the anuric oliguric phase plasma EPO levels were 4 times higher than in healthy subjects, while during the polyuric phase normal plasma levels were found in spite of the presence of anaemia. Results presented in this paper suggest presence of an abnormal feedback between EPO secretion and degree of anaemia in patients with acute noninflammatory renal failure both during the anuric/oliguric and polyuric phase respectively. Abnormal EPO secretion does not seem to be the only or even dominant factor involved in the pathogenesis of anaemia in patients with noninflammatory acute renal failure.

[Secretion of atrial natriuretic peptide and insulin in patients with kidney transplantation]

Influence of water immersion [WI] on atrial natriuretic peptide [ANP], insulin and glucose levels in kidney transplant patients [KTP] and healthy subjects [C] was observed. All KTP were divided on two groups - 35 patients treated by cyclosporine A+prednisone [CyA group] and 29 patients treated by azathioprine+prednisone [Aza group]. In all subjects plasma ANP, insulin and glucose levels were measured before and after 60 and 120 minutes of WI. KTP characterized a higher ANP level and lower insulin level than normals. WI induced statistically significant increase ANP and insulin levels and decrease glucose level in all groups. The increase ANP and IRI and decrease glucose were higher in healthy subjects. Only in healthy subjects a significant positive correlation were present between mean increase ANP and mean increase insulin and between mean increase ANP and mean decrease glucose level. Our results suggest lack of physiological relation between ANP and insulin. Kind of immunosuppressive therapy has only a minor influence on ANP and insulin changes during WI in KTP.

[Renin-angiotensin-aldosterone system (RAA) and vasopressin secretion in patients with chronic renal failure]

Influence of blockade converting enzyme on plasma renin activity (PRA), aldosterone and vasopressin secretion in 12 hemodialyzed patients with chronic renal failure and in 21 healthy subjects was observed. Our observation were provided during bed rest and water immersion tests. We didn't observe statistically significant influence PRA (increase after converting enzyme blockade) on vasopressin secretion in patients with chronic renal failure and in healthy subjects. Correlation between PRA and vasopressin secretion was absent.

Activity of the renin-angiotensin-aldosterone (RAA) and secretion of the atrial natriuretic peptide (ANP) in patients with chronic renal failure

In 12 patients with chronic renal failure (CRF) treated with haemodialyses and in 21 healthy controls plasma renin activity (PRA) and the concentrations of aldosterone and atrial natriuretic peptide (ANP) were determined in serum before and after blockade of the angiotensin converting enzyme with captopril. The study was carried out under conditions of the so called bed rest test (BR) and water immersion test (WI). After captopril administration a significant rise of PRA was noted in both groups with a drop of aldosterone level which was significant only in the control group. Captopril administration had no effect on serum ANP level. The results of the study are not suggesting the presence of a close relationship between ANP secretion and the activity of the RAA system in healthy controls and in CRF patients.

[Levels of ACTH and cortisol in patients with kidney transplantation examined during water immersion]

Influence of water immersion (WI) on ACTH and cortisol levels in 64 kidney transplant patients (KTP) (35 treated by cyclosporine A and prednisone and 29 by azathioprine and prednisone) and 15 healthy subjects were measured. Plasma cortisol level was lower, but ACTH normal in KTP. WI in all groups induced significantly decrease plasma ACTH and cortisol levels. This decrease was higher in controls than in KTP only in healthy subjects a significant correlation between ACTH and cortisol was present. Our results suggest: 1. dissociation pituitary-suprarenal function in KTP; 2. influence of immunosuppressive therapy on ACTH and cortisol levels after WI.

The activity of the renin-angiotensin-aldosterone (RAA) system and vasopressin secretion in patients with acute non-inflammatory renal failure

In 12 patients with acute non-inflammatory renal failure (ANRF) and in 21 healthy persons the relationship was studied between the activity of the renin-angiotensin-aldosterone (RAA) system and vasopressin secretion. The study was carried out during the so called bed rest test and during water immersion (WI) after captopril-induced blockade of the angiotensin-converting enzyme. The results of these experiments suggest the absence of a close functional relationship between the activity of the RAA system and vasopressin secretion in patients with ANRF and in healthy controls.

[Activity of plasma atrial natriuretic peptide level during acute rejection of kidney transplantation]

Plasma atrial natriuretic peptide (ANP) in 51 kidney transplant patients (KTP) during acute rejection (AR) was measured. All 51 KTP were divided in 3 groups. In the first group (16 subjects) patients were treated by azathioprine, predinisone and promethazine, in the second group (16 subjects) patients were treated by cyclosporine A and prednisone however in the third group (19 subjects) patients were treated by cyclosporine A, azathioprine and prednisone. Control group contained 15 subjects. ANP levels in KTP were measured four times: First time nearly 3 days before AR, second time immediately after recognition AR, third time after 3 days methylprednisone therapy and 4th time 3 days after stopping methylprednisone therapy. In all KTP before rejection ANP levels were slightly enhanced. During AR was observed statistically significant increase ANP levels in all KTP. After methylprednisone therapy plasma ANP level returned to basal (before rejection) level. Only before rejection a significant positive correlation was found between ANP and kidney function. All our result suggests participation of factors other than wicked kidney function in the pathogenesis enhanced ANP levels during AR. Kind of immunosuppressive therapy seems only a slightly influence on ANP levels in KTP before and after AR.

[Level of erythropoietin and parathormone in blood plasma during acute rejection of kidney transplant]

The acute rejection of kidney transplant is accompanied by kidney ischaemia which in turn is a triggering factor for erythropoietin (EPO) synthesis. It was shown, on the other hand, that during the rejection an increase in blood serum parathormone (PTH) concentration takes place. The present study was aimed at answering the question what is the effect of acute rejection of kidney transplant on blood serum concentrations of EPO i PTH. Seventeen patients with kidney transplant participated in the study. In all the patients the investigations were carried out four times: 1--few days before rejection, 2--after ascertaining that kidney transplant is being rejected, 3--immediately after rejection, and 4--few days after completing the anti-rejection therapy. High doses of methylprednisolone were used as anti-rejection therapy. Control group consisted of 16 healthy persons. Acute rejection of kidney transplant was accompanied by a significant increase in blood serum concentrations of EPO and PTH. After methylprednisolone therapy, normalization of EPO and decrease in PTH concentration were observed in kidney transplant patients. Significant positive correlations were found between EPO and PTH concentrations in blood serum. It was concluded that acute rejection of kidney transplant is characterized by a significant increase in blood serum concentrations of EPO and PTH. Despite the existence of a significant positive correlation between blood serum concentrations of EPO and PTH in patients with kidney transplant, any pathogenic relation between the observed disturbances of secretion of the two hormones seems to be of little probability.

Prolactin secretion in kidney transplant patients

In 27 male patients with a functioning kidney transplant and in 12 healthy male subjects plasma prolactin levels were estimated under baseline, inhibitory and stimulatory conditions, respectively. Kidney transplant patients (KTP) showed normal baseline plasma levels of prolactin, and a normal response of prolactinaemia to alpha-bromocriptine. In contrast, administration of chlorpromazine was followed by an exaggerated response of prolactin secretion in KTP as compared with normals. Type of immunosuppressive therapy (cyclosporine A or azathioprine) did not influence significantly the plasma prolactin profile in KTP under either inhibitory or stimulatory conditions.

Water immersion (WI) induced alterations of plasma vasopressin (AVP) levels in patients with noninflammatory acute renal failure (NARF) and in patients with chronic renal failure (CRF)

Water immersion (WI) induced alterations of plasma vasopressin (AVP), plasma osmolality, plasma volume (PV) and plasma sodium and potassium concentration were examined in 12 patients with noninflammatory acute renal failure (NARF) at the anuric/oliguric phase, 20 patients with chronic renal failure (CRF) and 15 healthy persons. In all examined groups a significant increase of PV and decrease of plasma osmolality and AVP after WI was observed. In patients with NARF the increase of PV was significantly greater than in CRF and in healthy persons. In patients with NARF a significantly greater decrease of plasma sodium concentration after WI was also noted than in patients with CRF and in healthy persons. Only in healthy persons, but not in patients with acute or chronic renal failure a significant correlation between PV or decrease of plasma osmolality and WI induced decrease of plasma AVP level was stated. We conclude that patients with NARF and CRF are characterized by an inappropriate volumetric and osmotic regulation of AVP secretion.

Water immersion induced alterations of plasma atrial natriuretic peptide (ANP), diuresis and natriuresis in kidney transplant patients

The present article aimed to study the intactness of the physiological mechanism of ANP secretion in 64 kidney transplant patients treated with cyclosporine A + prednisone (CyA group--35 patients) or azathioprine + prednisone + promethasine respectively (Aza group or--29 patients). The control group comprised 15 healthy persons. ANP plasma levels were assessed before and 1 h and 2 h after neck out water immersion (WI). Higher basal ANP levels were found in patients of the CyA and Aza group than in normals (significantly higher in patients of the CyA group). WI induced an increase of plasma volume (PV) which was of comparable magnitude in all examined groups. It was accompanied by a significant increase of plasma ANP, diuresis and of natriuresis, which was significantly lower in transplanted patients than in normals. Only in healthy persons a significant positive correlation was found between the WI induced increase of plasma ANP and diuresis and natriuresis respectively.

CONCLUSIONS

1) kidney transplant patients are characterized by an intact, although reduced response of ANP secretion, diuresis and natriuresis to central hypervolaemia; 2) WI induced increase of diuresis and natriuresis does not seem to be only dependent upon ANP secretion in kidney transplant patients; 3) kind of immunosuppressive therapy seems to be of importance in the pathogenesis of altered ANP secretion in kidney transplant patients.

[Treatment of anemia in patients with renal failure using erythropoietin obtained by genetic recombination]

In 5 haemodialyzed patients with end-stage renal failure an effect of human recombinant erythropoietin (r-huEpo) on haemoglobin, haematocrit and iron metabolism was studied. After 12 weeks of the treatment, a significant increase in haemoglobin and haematocrit but significant decrease in plasma ferritin were noted. During r-huEpo treatment, one patients presented clinical symptoms of increased blood coagulation whereas another patients an increase in blood pressure. r-huEpo did not influence leukocytes and platelets count as well as liver function tests. Our results suggest, that r-huEpo is highly effective and safe in the treatment of anaemia in patients with chronic uraemia. Iron metabolism, blood pressure and blood coagulation must be monitored during therapy with r-huEpo.

Influence of erythropoietin treatment on function of the pituitary-adrenal axis and somatotropin secretion in hemodialyzed patients

In five hemodialyzed patients the influence of erythropoietin (EPO) treatment for 3 months on function of the pituitary-adrenal feedback and STH secretion was studied. Results were compared with those obtained in 6 hemodialyzed patients (No-EPO group) showing a comparable Hb concentration and Hct value as patients in the EPO group post-treatment and in 15 healthy subjects. EPO treatment was followed by a significant (ACTH and STH) or moderate (cortisol) suppression of basal plasma levels of ACTH, STH and cortisol respectively, and by a significant reduction of the response of plasma concentrations of these hormones to insulin-induced hypoglycemia. As the response of plasma levels of ACTH, STH and cortisol respectively in patients of the EPO group post-treatment differed markedly from that of the No-EPO group with similar Hb and Hct values, it seems that the EPO-induced endocrine alterations are not, at least not exclusively, a consequence of the improvement of anemia. Results presented in this study suggest that EPO treatment influences directly or indirectly the function of endocrine organs.

Water immersion induced alterations of plasma vasopressin levels and activity of the renin-angiotensin-aldosterone system in noninflammatory acute renal failure and end-stage renal failure

Water immersion (WI) induced alterations of plasma renin activity (PRA), plasma aldosterone (Aldo), vasopressin (AVP), sodium and potassium concentrations and plasma volume (PV) were examined in 12 patients with noninflammatory acute renal failure (NARF) in the anuric/oliguric phase, in 20 patients with chronic renal failure (CRF) and in 15 healthy subjects. In all examined groups a significant increase of PV and decrease of PRA, plasma Aldo, AVP after WI were observed. Significantly more marked decreases of PRA were observed in patients with NARF than in those with CRF and in healthy subjects. In patients with NARF the increase of PV was significantly greater than in CRF and in healthy subjects. In patients with NARF a significantly more marked decrease of plasma sodium concentration was also noted after WI than in subjects with CRF and in normals. Only in healthy subjects was a significant negative correlation noted between the WI increase of PV and decrease of plasma AVP level. In healthy subjects, significantly positive correlations were noted between WI induced decrease of PRA and Aldo and between PRA and plasma AVP, respectively. Such correlations were absent in uraemic patients.

IN CONCLUSION

(1) patients with CRF and NARF show similar, but quantitatively different responses of PRA, Aldo and AVP secretion to WI as compared with normals; (2) patients with NARF and CRF are characterized by an inappropriate volumetric and osmotic regulation of AVP secretion; (3) in uraemic patients the physiological relationship between the renin-angiotensin system and AVP secretion seems to be dissociated.

[Studies of atrial natriuretic peptide, diuresis and natriuresis in patients with diabetes mellitus types 1 and 2 after water immersion]

In 30 diabetics (15 with type I and 15 with type II) and in 15 healthy controls the effect was studied of two-hour immersion in water on the concentration of atrial natriuretic peptide, sodium and potassium in serum, diuresis and natriuresis, mean arterial pressure and percent change of circulating plasma volume. Diabetics with either type of diabetes differed from the controls by a significantly lower concentration of the atrial natriuretic peptide under basal conditions, and lower rise of the peptide during immersion in water. Type I diabetics differed from type II diabetics and controls in that their natriuresis was lower under basal conditions and during immersion. On the basis of these results the authors conclude that in diabetics the reaction of atrial natriuretic peptide secretion to central hypervolaemia is preserved but weaker, and the role of this hormone in the pathogenesis of increased diuresis and natriuresis induced by water immersion is smaller in these patients than in controls.

[Effect of adrenergic beta receptor blockaders and thiazide diuretics on gastric acid and gastrin secretion in patients with essential hypertension]

The purpose of the study was to evaluate the effect of 6 weeks treatment with hydrochlorothiazide or propranolol on gastric acid and gastrin secretion in essential hypertension. The study was carried out in 10 patients receiving propranolol and 10 treated with hydrochlorothiazide. Acid and gastrin secretion were determined during histamine stimulation tests (Kay's test). Before the treatment the patients with essential hypertension were not significantly different from healthy controls with respect to acid secretion and gastrinemia profile after histamine stimulus. In both groups of patients no significant effect was observed of hypotensive treatment on basal acid output, but a significant inhibitory effect on gastrin secretion was noted. This effect was significantly greater in patients treated with propranolol than in the hydrochlorothiazide group. Moreover, in propranolol-treated patients a significant fall of histamine-induced acid secretion was found.

[Selected parameters of calcium and phosphate metabolism in patients after kidney transplantation and administration of azathioprine or cyclosporin A]

The influence was studied of the type of immunosuppression on calciuria, phosphaturia, and on the levels of parathyroid hormone (PTH), calcitonin (CT), 25-hydroxycholecalciferol (25/OH/D), total calcium, magnesium, and alkaline phosphatase activity in 24 patients after renal transplantation. Twelve of these patients received cyclosporin with prednisone (group CyA) and other 12 were treated with azathioprine and prednisone (group Aza). Independently of the type of immunosuppression used, in both groups a significantly higher concentration of PTH, CT, 25/OH/D and greater activity of alkaline phosphatase were demonstrated in relation to healthy controls. In both studied groups the patients had also a significantly reduced calciuria and phosphatemia than controls. In group Aza the patients had a significantly lower phosphaturia and significantly higher magnesemia than in group CyA. The results of these investigations suggest a certain influence of the type of immunosuppression on the intensity of calcium-phosphate metabolism in renal graft recipients.

Influence of erythropoietin treatment on follitropin and lutropin response to luliberin and plasma testosterone levels in haemodialyzed patients

Plasma levels of follitropin (FSH), lutropin (LH) and testosterone (TE) were estimated in 5 anaemic haemodialyzed patients before and after 3 months of erythropoietin treatment (EPO group), in 5 male haemodialyzed patients with a haematocrit value of 33% (which was of the same magnitude as the post-treatment haematocrit value in the EPO group) and in 15 male healthy subjects. After EPO treatment, haematocrit values rose from 23.0 +/- 0.9 to 34.6 +/- 0.75%. EPO treatment induced a significant suppression of basal plasma FSH and LH levels, while plasma TE levels slightly increased. After EPO treatment, the response of plasma FSH and LH to luliberin administration was significantly reduced. As the endocrine profile of EPO-treated patients differed from that of haemodialyzed patients showing a similar haematocrit value, it seems that EPO-induced hormonal changes are not or not only related to improvement of anaemia. Normalization of the pituitary-gonadal feedback in EPO treatment seems to participate in the pathogenesis of improved sexual activity in these patients.

Endocrine function of the pancreas and gastrin secretion in patients with a kidney transplant

In 24 patients with a kidney transplant and in 10 healthy subjects the test meal response of immunoreactive insulin (IRI), glucagon (IR-G), pancreatic polypeptide (IR-PP) and gastrin (IR-Ga) was studied. Patients with a kidney transplant showed significantly elevated basal plasma glucagon levels but normal levels of plasma IRI, IR-PP and IR-Ga. After administration of a test meal a significantly suppressed response of IRI, IR-PP and IR-Ga secretion was observed both in the patients treated with azathioprine as well as those treated with ciclosporin. In patients of the ciclosporin group the compromised response of IR-Ga and IRI secretion was significantly more marked than in subjects in the azathioprine group. From the results obtained in this paper it follows that the type of immunosuppressive drugs (azathioprine or ciclosporin) seems to be of minor importance in the pathogenesis of the described endocrine abnormalities.

Endocrine alterations in kidney transplant patients

Several factors are involved in the persistence of endocrine alterations after renal transplantation, among which the following are to be mentioned: (1) duration of chronic uraemia before renal transplantation; (2) residual function of the patients' native kidneys; (3) quality of function of the renal graft; (4) modulation of secretion, transport, and degradation of hormones, and/or (5) altered target organ responsiveness to hormones induced by immunosuppressive drugs (glucocorticoids, azathioprine, cyclosporin A) or altered internal environment. In kidney transplant patients the following endocrine abnormalities are to be mentioned: dissociation of the physiological relationship between aldosterone synthesis and function of the renin-angiotensin system, abnormal volumetric regulation of arginine vasopressin secretion, suppressed responsiveness of cortisol secretion to stimulatory manoeuvres, persistent secondary hyperparathyroidism, relative deficiency of insulin (induced by glucocorticoid therapy), with consequent carbohydrate intolerance or even diabetes mellitus, suppressed response of gastrin and pancreatic hormone secretion to a test meal, and reduced responsiveness of atrial natriuretic peptide secretion to central hypervolaemia. Episodes of acute graft rejection are characterized by endocrine alterations similar to those seen in patients with acute or chronic renal failure.

[Effect of water immersion on levels of atrial natriuretic peptide in patients with chronic renal failure]

An effect of a 2-hour water immersion on the blood serum ANP was investigated in 20 haemodialysed patients with chronic renal failure and in 15 healthy individuals. Water immersion produced an increase in volume in both healthy individuals and the patients of similar degree. Baseline ANP concentration (290.0 +/- 21.9 pg/mL) was significantly higher in the dialysed patients than that in healthy individuals (66.0 +/- 5.5 pg/mL). Water immersion decreased mean arterial pressure (previously significantly higher in the patients) in both healthy individuals and examined patients, significantly increased secretory renal function (significantly higher in healthy individuals than in the examined patients), and increased ANP (previously significantly higher in healthy subjects). A significant correlation between ANP level in blood serum and changes in volume was seen only in healthy individuals. The obtained results suggest a contribution of other than changed volume factors of ANP release regulation and other than ANP factors to pathomechanism of post-immersion drop of the arteria blood pressure and increased secretory renal function in both healthy individuals and patients with renal failure.