1.Selective determination of C-terminal (70-84) hPTH: elevated concentrations in cholestatic liver disease.
Rittinghaus EF, Jüppner H, Burdelski M, Hesch RD. Acta Endocrinol (Copenh). 1986 Jan;111(1):62-8.
In order to obtain a better resolution of circulating PTH-fragments, we developed a radioimmunoassay with an antiserum raised against the synthetic 70-84 hPTH molecule in a sheep. [125I](69 Tyr) 70-84 hPTH was used as the radioactive tracer with the antiserum at a final dilution of 1:200 000. Displacement curves showed that only the 70-84 hPTH, (69 Tyr) 70-84 hPTH and 53-84 hPTH fragments were able to compete with the tracer. Synthetic 28-48 hPTH, 44-68 hPTH, (61 Tyr)62-68 hPTH, purified 1-84 hPTH and 53-84 bPTH showed no ability to displace the tracer indicating that the idiotype of the antibody is directed against the 70-84 portion that is usually hidden within the globular structure of the intact molecule. Healthy adults revealed PTH-peptide levels of 153 +/- 86 pg/ml (mean +/- 2 SD); 2 SD range: 67-239 pg/ml. C-terminal PTH-peptide (70-84 hPTH) concentration was normal in patients with primary hyperparathyroidism and chronic renal failure, thus excluding that neither the kidney nor the parathyroid gland is involved in the generation of this C-terminal PTH-peptide sequence.
2.Bone density and metabolism in patients with viral hepatitis and cholestatic liver diseases before and after liver transplantation.
Trautwein C1, Possienke M, Schlitt HJ, Böker KH, Horn R, Raab R, Manns MP, Brabant G. Am J Gastroenterol. 2000 Sep;95(9):2343-51.
OBJECTIVE: Osteoporosis is frequently found in patients with cholestatic liver disease (primary biliary cirrhosis/primary sclerosing cholangitis) and chronic viral hepatitis. There is limited information about the long-term effect of liver transplantation (OLT) on bone metabolism. The aim of this study was to investigate the effect of liver transplantation on bone metabolism in patients with cholestatic and viral liver diseases.
3.The 69-84 amino acid region of the parathyroid hormone molecule is essential for the interaction of the hormone with the binding sites with carboxyl-terminal specificity.
Takasu H1, Baba H, Inomata N, Uchiyama Y, Kubota N, Kumaki K, Matsumoto A, Nakajima K, Kimura T, Sakakibara S, Fujita T, Chihara K, Nagai I. Endocrinology. 1996 Dec;137(12):5537-43.
We evaluated the competitive inhibitory effect of intact PTH, the amino-terminal PTH(1-34) fragment, and a series of truncated carboxyl-terminal PTH fragments on the binding of internally 35S-labeled human PTH(1-84) ([35S]hPTH(1-84)) to osteoblastic cells (ROS 17/2.8), in order to identify the minimum and critical elements within the PTH molecule for the interaction with the binding sites specific for the carboxyl-terminal region of the hormone. When the amino-terminal region of the PTH molecule was truncated stepwise, hPTH(35-84), hPTH(53-84) and hPTH(69-84), but not hPTH(70-84), significantly inhibited the [35S]hPTH(1-84) binding. On the other hand, the simple deletion of the carboxyl-terminal glutamine at position 84 of hPTH(53-84) [hPTH(53-83)] resulted in blunting the inhibitory effect of the peptide on the [35S]hPTH(1-84) binding. Furthermore, hPTH(35-84), hPTH(53-84) and hPTH(69-84), but not hPTH(70-84) nor hPTH(53-83), augmented the inhibitory effect of the amino-terminal PTH fragment [hPTH(1-34)] on the [35S]hPTH(1-84) binding.