Histamine H₂ receptor activity during the differentiation of the human monocytic‐like cell line U‐937

Abstract

Histamine H2 receptor activity (cAMP generation) has been characterized in U‐937 cells before and after retinoic acid‐induced differentiation into monocyte‐/macrophage‐like cells. The differentiation is associated with a decreased capacity of U‐937 monocytes to generate cAMP under basal conditions or after cell surface receptor stimulation by histamine, isoproterenol and PGE1. In contrast, the potencies of the hormones are unchanged during monocytic maturation (EC 50 values = 3.2–4.6 × 10−6 M histamine, 4.6–7 × 10−9 M isoproterenol, 2–4.6 × 10−6 M PGE1). The data support the view that histamine and cAMP‐inducing agents may control the proliferation and differentiation of normal and leukemic cells committed to monocytic maturation in man. They also raise the possibility that normal human monocytes also possess functional H2 receptors and that histamine may be implicated in the regulation of monocyte/macrophage functions.

Vasoactive intestinal peptide receptor activity and specificity during enterocyte‐like differentiation and retrodifferentiation of the human colonic cancerous subclone HT29‐18

“…The same observation was made during retinoic acid-induced monocytic differentiation of the human histiocytic lymphoma cell line U-937 [34,35].…”

CCL22/Macrophage-derived Chemokine Expression in Apolipoprotein E-deficient Mice and Effects of Histamine in the Setting of Atherosclerosis

“…5C). Moreover, the histamine H1 blocker did not affect the expression of CCL22, whereas the histamine H2 blocker decreased the expression of cell line U937 [16][17][18] , and the regulation of CCL22 was dependent on the presence of H2 receptor in the present study. These result suggest that the effects of histamine on the CCL22 expression are limited in mature macrophages.…”

Molecular and cellular analysis of human histamine receptor subtypes

“…The existence of ligand-specific receptor conformations is further supported by data from HL-60 leukemia cells that also express H 2 R. In these cells, H 2 R mediates both an increase in cAMP and in [Ca 2+ ] i , but the potencies and efficacies of various H 2 R agonists for both responses are relatively different [35,36]. U937 promonocytes are a model system for AML forms M4/M5 and have been used to study the hH 2 R in terms of structure/activity relationships of ligands [37,38], models of receptor activation [39], desensitization [40], gene expression [41], and myeloid differentiation [42]. …”