Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.1.17 (ornithine decarboxylase)
 6,351 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prolactin receptors have been identified for the first time on human peripheral blood lymphocytes. These receptors are present on T- and B-cells as well as monocytes. The specific binding of [125I]prolactin to these cells can be selectively enhanced at certain concentrations and blocked by higher concentrations of cyclosporine , a known immunosuppressive agent which inhibits the mitogenesis of T-cells. Prolactin also induces ornithine decarboxylase, a key growth regulatory enzyme, in lymphocytes. Therefore, we suggest that the lymphocyte prolactin receptor may be involved in regulating lymphocyte function, and that one of the actions of cyclosporine is to block this rather ubiquitously occurring receptor.
 ...
PMID:Prolactin receptors on human lymphocytes and their modulation by cyclosporine. 633 35

Human prolactin (hPRL) induced ornithine decarboxylase (ODC) activity, subsequently DNA synthesis and cellular proliferation on human promyelocytic cells, HL60, cultured in a serum-free medium. HL60 cells had 2100 specific binding sites for hPRL per cell, showing a dissociation constant of 1.1 x 10(-10) M. Binding of 125I-PRL to the cells was not blocked by simultaneous addition of human growth hormone. ODC activity and DNA synthesis were activated maximally at 5 and 20 h, respectively, after the addition of 0.05 nM hPRL. These effects of PRL on cellular proliferation, ODC activity and DNA synthesis were abolished by the simultaneous addition of anti-hPRL antibody. Simultaneous addition of an irreversible inhibitor of ODC, difluoromethyl ornithine (DFMO), also abolished the inductions of ODC and DNA synthesis by hPRL. The inhibitory effect of DFMO on hPRL-induced DNA synthesis was reversed by the addition of putrescine to the culture medium. These results suggest that hPRL binds to the prolactin receptor on HL60 cells and induces ODC activity to increase cellular polyamine levels, which eventually stimulates DNA synthesis and cellular proliferation.
 ...
PMID:Human promyelocytic cell line HL60 has the specific binding sites for prolactin and its ornithine decarboxylase, DNA synthesis and cellular proliferation are induced by prolactin. 835 6