title: IL-4 induces cAMP and cGMP in human monocytic cells.
abstract: Human monocytes, preincubated with IFN-gamma respond to IL-4 by a cGMP increase through activation of an inducible NO synthase. Here, IL-4 was found to induce an accumulation of cGMP (1 - 3 min) and cAMP (20 - 25 min) in unstimulated monocytes. This was impaired with NOS inhibitors, but also with EGTA and calcium/calmodulin inhibitors. These results suggest that: (1) IL-4 may stimulate different NOS isoforms in resting and IFN-gamma activated monocytes, and (2) cAMP accumulation may be partially dependent on the NO pathway. By RT-PCR, a type III constitutive NOS mRNA was detected in U937 monocytic cells. IL-4 also increased the [Ca(2+)](i) in these cells. Different NOS may thus be expressed in monocytic cells depending on their differentiation and the signals they receive.
authors.affiliation: URA CNRS 625 Hôpital Pitié-Salpêtrière Paris 75013 France.
authors.forename: B
authors.initials: B
authors.lastname: Dugas
authors.forename: N
authors.initials: N
authors.lastname: Paul-Eugene
authors.forename: K
authors.initials: K
authors.lastname: Yamaoka
authors.forename: C
authors.initials: C
authors.lastname: Amirand
authors.forename: C
authors.initials: C
authors.lastname: Damais
authors.forename: J P
authors.initials: JP
authors.lastname: Kolb