Growth hormone and insulin binding to human liver.
Specific binding of 125I-hGH to human liver was found in autopsy specimens from 12 to 15 patients. Specific binding was studied using a new technique employing 20 mu thich "microslices" cut on a cryostat. About 0.5 to 1 mg of tissue per assay tube makes feasible the study of small samples. The range of specific binding was 1.4 to 11.7% of 80,000 cpm 125I-hGH added expressed per mg dry weight of tissue. Specific binding was also demonstratable in homogenates and crude membrane preparations from liver. No correlation was seen between 125I-hGH binding and age, sex, or pathology in the series of patients studied. No specific binding of 125I-hGH was observed in lung, adrenal, spleen, or kidney, although all the tissues bound 125I-insulin. Of several species of growth hormone tested, only primate GH displaced 125I-hGH from its binding sites in human liver. No displacement was seen with ovine or human prolactin or with insulin. Primate placental lactogens had only 0.5-1.0% potency of native hGH in displacing 125I-hGH from human liver. Ungulate placental extracts, however, were equipotent with hGH in this respect.
D000311:Adrenal Glands / Q000378:metabolism; D000328:Adult; D000368:Aged; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D007328:Insulin / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011485:Protein Binding; D011869:Radioligand Assay; D013154:Spleen / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
D007328:Insulin; D007457:Iodine Radioisotopes; D013006:Growth Hormone