Effect of Dialysate Calcium Concentration on Plasma Parathyroid Hormone during Hemodialysis

Ch, McIntosh; Fuchs, Christoph; Dorn, D.; Quellhorst, E; Hv, Henning; Rd, Hesch; Scheler, F.

doi:10.1159/000180870

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…This observation is in agreement with Tsulsumi et al [10], who also detected carboxy terminal fragments in plasma filtrate, and with Zanelli and Gaines-Das [9] who ob served that most of the immunoreactivity in plasma filtrate can only be detected by car boxyl region RIA. This might be the main reason for the immediate decrease in car boxyterminal iPTH in plasma during a he modialysis session [1,6,7], In addition, fragments of PTH with a very low molecular weight which were not de tected in plasma appear in the dialysate after in vivo ultrafiltration. It is possible that they have been generated during the passage through the membrane, either as a conse quence of the transmembrane pressure or fol lowing the action of proteases coming from hemolyzed blood cells.…”

Section: Discussionmentioning

confidence: 99%

“…In patients with end-stage renal failure, raising the calcium level of the dialysatc has repeatedly been shown to lead to decrement in basal plasma immunoreactive parathyroid hormone (iPTH) concentration [1,2]. The link between both facts has first been thought to be suppression of PTH secretion [3].…”

Section: Introductionmentioning

confidence: 99%

“…The link between both facts has first been thought to be suppression of PTH secretion [3]. But this phenomenon is not constant, several au thors having observed unchanged basal iPTH levels [4,5], Actually, the immediate changes in plasma iPTH during hemodialysis seem to be unpredictable: decrease [6] as well as in crease [1] in iPTH, measured in an aminoter minal assay, have both been reported, whereas in a carboxyterminal assay iPTH generally decreases [1,6,7], The surprising increase in aminoterminal iPTH parallels hemoconcentration [1] or could reflect inhib ited metabolism of N-tcrminal fragments; the paradoxical rise in basal iPTH might reflect PTH stimulation occurring between the dialysis sessions [2], However, mecha nisms additional to stimulation and inhibi tion of hormone secretion and metabolism must be invoked to explain the various, ap parently discrepant changes in iPTH during hemodialysis and hemofiltration. It has al ready been suggested that clearance of PTH or PTH fragments might be involved [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Fate of Parathyroid Hormone during Hemodialysis and Ultrafiltration

Burckhardt¹,

Jaeger²,

Jacquet³

et al. 1985

Horm Res

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In order to shed light on the discrepant changes in plasma immunoreactive parathyroid hormone (iPTH) during hemodialysis (HD) and ultrafiltration (UF) in end-stage renal failure, the influence of filtration of PTH fragments on the iPTH level in plasma was examined in 2 sets of experiments: in vitro dialysis of ¹²⁵I-bPTH 1-84, ¹²⁵I-hPTH 1–34 and ¹²⁵I-hPTH 53-84 added to plasma was successively performed through a cuprophane membrane. Gel filtration on a Biogel P-100 column and subsequent counting of the eluate were performed with the plasma before and after dialysis, and with the dialysate fluid after dialysis. An ultrafiltrate obtained from a patient with renal failure was also analyzed for iPTH with a ‘C-’ and with an ‘N-terminaΓ antiserum (GP 500 MA and AS 211/32), and so was his plasma before and after UF, and after a subsequent dialysis session. Fluid obtained by lavage of the filter with acetic acid after dialysis was also analyzed. Chromatography with measurements of iPTH in the eluate was performed in each case, and the procedure was repeated applying a different transmembrane pressure. Immunoreactive material found in the concentrated ultrafiltrate, but not in plasma, was characterized by means of dilution curves in different RIA performed with the C-terminal antiserum preincubated with various synthetic PTH fragments. Results showed that intact PTH does not cross the cuprophane membrane during both in vitro dialysis and in vivo UF. The 1-34 fragments are poorly dialyzed in vitro; either they stick to the membrane or they are disintegrated. 53-84 and other low molecular weight (MW) fragments cross the membrane during both in vitro dialysis and in vivo UF and they disappear from the plasma during HD. During UF low MW fragments which were not detected in plasma and which react with both antisera appear in the ultrafiltrate. Characterization of these fragments by RIA reveals that their antigenic site is located within the midregion of the PTH molecule. It is concluded that decline in iPTH levels during in vivo HD reflects not only inhibition of PTH secretion following the increase in plasma calcium, but also passage of carboxyterminal PTH fragments through the filter. In addition, midregion PTH fragments appear in the concentrated ultrafiltrate, which are not detected in the plasma and which also might have been filtered during UF.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fate of Parathyroid Hormone during Hemodialysis and Ultrafiltration

Burckhardt¹,

Jaeger²,

Jacquet³

et al. 1985

Horm Res

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show abstract

“…Derangements of calcium homeostasis in renal failure impose a special burden on nephrologists to take corrective measures during hemodialysis treatments. Whereas enhancing calcium uptake during treatment was thought to be mandatory until recently both to improve calcium balance (1) and to suppress secondary hyperparathyroidism (2,3), lower dialysate calcium is advocated currently when either calcium salts are prescribed for intestinal phosphate binding (4) or in cases of vitamin D treatment (5).…”

mentioning

confidence: 99%