Detection of XXXX growth hormone receptors on IM-9 cells and peripheral blood mononuclear cell subsets by flow cytometry: correlation with growth hormone-binding protein levels.

@entity1 @entity2338 @entity851 @entity18299 @entity30 @entity2012 @entity2689 @entity74 @entity941 @entity774 @entity35 @entity291 @entity9045
We have developed a method using flow cytometry to identify @entity941 -conjugated GH receptors ( @entity9045 ) on IM-9 lymphocytes and circulating peripheral blood mononuclear cell subsets. Binding to IM-9 cells and peripheral blood mononuclear cells was concentration dependent and could be competitively blocked by the addition of unlabeled @entity1 GH, but not by the addition of @entity35 or @entity291 GH or @entity1 insulin or PRL. Using two-color flow cytometric analysis, @entity941 -conjugated @entity1 @entity9045 were readily detected on more than 90% of B lymphocytes and monocytes, but only variably on T lymphocytes. B Lymphocytes and monocytes had approximately 6000 @entity9045 /cell. Using two-color flow cytometry, we identified @entity9045 on circulating B lymphocytes in subjects with @entity2338 (n = 9), precocious puberty (n = 6), and @entity2689 (n = 5) and in seven subjects with @entity74 , including @entity851 , @entity18299 , @entity30 , @entity774 , and @entity2012 . The percentage of B lymphocytes expressing @entity9045 in subjects with @entity2338 (mean +/- SD, 95 +/- 9%), precocious puberty (91 +/- 15%), and @entity2689 (84 +/- 15%) was not different from that in normal volunteers (90 +/- 12%; n = 14). In 10 subjects, serum GH-binding protein levels were assayed simultaneously with B lymphocyte @entity9045 . GH-binding protein was normal in all (mean, 1255 pmol/L; range, 773-1809). There was a good correlation between @entity9045 expression on B lymphocytes and GH-binding protein levels (r = 0.75; P = 0.01). We postulate that @entity9045 found on circulating B lymphocytes may contribute to the pool of receptors identified in serum as GH-binding proteins. Two-color flow cytometry appears to be an effective method for the detection of @entity9045 on circulating peripheral blood mononuclear cell subsets. The evaluation of @entity9045 on circulating B lymphocytes may prove to be a useful means of evaluating GH- @entity9045 interactions in subjects with @entity851 .
