scholarly journals Parathyroid hormone-related protein detection and interaction with NO and cyclic AMP in the renovascular system

1996 ◽  
Vol 50 (5) ◽  
pp. 1591-1603 ◽  
Author(s):  
Thierry Massfelder ◽  
Andrew F. Stewart ◽  
Karlhans Endlich ◽  
Neil Soifer ◽  
Clément Judes ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Protein Detection ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein

Effects of two synthetic parathyroid hormone-related protein fragments on maternofetal transfer of calcium and magnesium and release of cyclic AMP by the in-situ perfused rat placenta

1991 ◽  
Vol 129 (3) ◽  
pp. 399-404 ◽  
Author(s):  
A. J. Shaw ◽  
M. Z. Mughal ◽  
M. J. A. Maresh ◽  
C. P. Sibley
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Ringer Solution ◽  
Related Protein ◽  
Placental Perfusion ◽  
Protein Fragments ◽  
Parathyroid Hormone Related Protein ◽  
Peak Release ◽  
Similar Peak

ABSTRACT Two human parathyroid hormone-related protein (hPTHrP) fragments were tested for effects on maternofetal transfer of 45Ca and Mg across the in-situ perfused rat placenta at 21 days of gestation (term = 23 days). The fetal placental circulation was perfused with a Mg-free Krebs–Ringer solution and the unidirectional maternofetal clearance (Kmf) of 45Ca and Mg compared with that of 51Cr-EDTA, the latter being employed as a paracellular diffusional marker. Placental perfusion with hPTHrP(1–34) (100 ng/ml) or hPTHrP(75–86)amide (50 ng/ml) did not significantly alter the Kmf of 45Ca or that of Mg. In separate rats, however, hPTHrP(1–34) but not hPTHrP(75–86)amide stimulated marked placental cyclic AMP (cAMP) release, the peak response of 63±7 pmol/min occurring 10 min after the beginning of the peptide perfusion. A lower dose of hPTHrP(1–34) (4 ng/ml) produced a similar peak release of cAMP, as did [Nle8,21,Tyr34]-rPTH(1–34)amide (4 ng/ml) and the adenylate cyclase agonist forskolin (17 μmol/l). Forskolin also rapidly increased the Kmf of 45Ca but not that of Mg or 51Cr-EDTA. The present study indicates that hPTHrP does not acutely affect maternofetal transfer of Ca or Mg across the perfused rat placenta. The data also question the role played by cAMP in the stimulatory actions of forskolin on placental Ca transport. Journal of Endocrinology (1991) 129, 399–404

Identification and partial characterization of parathyroid hormone-related protein in human and bovine milk

1990 ◽  
Vol 127 (1) ◽  
pp. 167-176 ◽  
Author(s):  
W. A. Ratcliffe ◽  
E. Green ◽  
J. Emly ◽  
S. Norbury ◽  
M. Lindsay ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Molecular Species ◽  
Bovine Milk ◽  
Gel Filtration ◽  
Molecular Forms ◽  
Gel Chromatography ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein

ABSTRACT Parathyroid hormone-related protein (PTHrP) was measured in human and bovine milk by radioimmunoassay (RIA) and bioassay, and the molecular forms characterized by gel chromatography and immunoblotting of affinity-purified PTHrP. Mean immunoreactive PTHrP(1–34) concentrations were 23 and 87 μg/l in human and bovine milk respectively. Bioactive (BIO) PTHrP concentrations determined by cyclic AMP production by ROS 17/2·8 cells correlated significantly (P< 0·001) with those obtained by RIA (BIO = 1·04RIA−3·4, r = 0·939). Gel filtration of human and bovine milk identified several peaks with immunoactivity and bioactivity. Immunoblotting of affinity-purified PTHrP revealed multiple molecular species including components with mobilities similar to those of PTHrP and its subfragments. These studies confirm the presence of immuno- and bioactive PTHrP in milk and suggest that post-translational processing is complex and variable. Journal of Endocrinology (1990) 127, 167–176

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