Characterization of putative growth hormone receptors in human choroid plexus.
The ability to bind iodine-labelled human growth hormone ([125I]hGH) was measured in different parts of the human brain. The choroid plexus contained the highest amount of binding sites (receptors) and was therefore selected for further studies. The binding between [125I]hGH and the receptor was saturable, of high affinity (Ka = 0.63 nM-1) and pH- as well as time-dependent. After solubilization with Triton X-100 the receptors retained their hormone-binding properties and eluted in the high molecular weight range (greater than 500,000) upon molecular sieve chromatography. Analysis by an affinity cross-linking technique indicated a hormone-binding unit of molecular weight 51,000. The molecular characteristics of the identified binding sites are discussed in comparison to those of growth hormone receptors of human and animal origin.
Lai
Z N
ZN
Department of Pharmaceutical Pharmacology, University of Uppsala, Sweden.
Emtner
M
M
Roos
P
P
Nyberg
F
F
D000328:Adult; D001921:Brain / Q000378:metabolism; D002831:Choroid Plexus / Q000378:metabolism*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D011869:Radioligand Assay; D011986:Receptors, Somatotropin / Q000187:drug effects*; D012737:Sex Factors
D007457:Iodine Radioisotopes; D011986:Receptors, Somatotropin