title: Hormonal regulation of peripheral blood mononuclear cells in sheep.
abstract: The presence of growth hormone receptors (GHR) on sheep peripheral blood mononuclear (PBMN) cells was studied in two ways. The first was to directly measure specific GH-binding sites on PBMN cells drawn from lambs from birth to 5 months of age. The second was to measure the effect of GH on resting and interleukin-2 (IL-2)-activated PBMN cells in vitro and also the effect of other hormones such as prolactin (PRL), insulin-like growth factor-1 (IGF-1), and glucocorticoid. The specific binding of [125I]human GH (hGH) was low on PBMN cells but increased (P < 0.05) with age up to 5 months. Interestingly, serum concentrations of GH-binding protein also increased (P < 0.01) with age and were highly correlated (r = 0.89; P < 0.05) with the specific binding of GH to PBMN cells. The addition of ovine GH (oGH) to PBMN cells in vitro resulted in increased (P < 0.01) proliferation (at a dose of 100 ng/ml). Higher doses of oGH (2 micrograms/ml) also increased PBMN cell proliferation. When PBMN cells were previously stimulated with IL-2, the dose of 100 ng/ml) oGH was no longer able to stimulate proliferation. IGF-1 inhibited (P < 0.04) resting PBMN cell proliferation at 100 ng/ml but had no effect on IL-2-activated PBMN cells. Other hormones such as PRL caused a stimulation of PBMN cell proliferation (P < 0.01) at 100 ng/ml, whereas dexamethasone (dex) inhibited PBMN cell proliferation at doses as low as 63 ng/ml. These studies show that GH, PRL, IGF-1, and glucocorticoids are effective in modulating the proliferation of PBMN cells from sheep and therefore suggest that a modulation of immune system function in vitro by these hormones is consistent with a purpose in vivo.
authors.affiliation: Department of Animal Sciences, Oregon State University, Corvallis 97331-6702, USA.
authors.forename: M
authors.initials: M
authors.lastname: Khosraviani
authors.forename: S L
authors.initials: SL
authors.lastname: Davis
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology; D013006:Growth Hormone / Q000097:blood / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007457:Iodine Radioisotopes; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D011388:Prolactin / Q000494:pharmacology; D011986:Receptors, Somatotropin / Q000378:metabolism*; D012756:Sheep / Q000097:blood*
chemical_list: D005938:Glucocorticoids; D006728:Hormones; D007376:Interleukin-2; D007457:Iodine Radioisotopes; D011986:Receptors, Somatotropin; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D013006:Growth Hormone