Figure 8.
Longer Hpα peptides activate a signal transduction pathway distinct from the pathway activated by classic CB1 receptor agonists: calcium release. A) Neuro 2A cells (7–18 cells) were treated 1 min before data recording with 1 μM Hu-210, RVD-Hpα, VD-Hpα, or 2-AG. The free Ca2+ concentration was calculated as described in Materials and Methods. Data represent means ± se of 7–18 cells. B) Neuro 2A cells were treated 1 min before data recording with 1 μM Hu-210, RVD-Hpα, or Hpα in the absence or presence of 10 μM SR141716. Data represent means ± se of 7–18 cells. C) Neuro 2A cells were treated in the presence or absence of PTX before data recording with 1 μM RVD-Hpα. The free Ca2+ concentration was calculated as described in Materials and Methods. Data represent means ± se of 7–18 cells. D) Neuro 2A cells were treated in the presence or absence of Ca2+-free medium 1 min before data recording with 1 μM RVD-Hpα. The free Ca2+ concentration was calculated as described in Materials and Methods. Data represent means ± se of 18–22 cells.