“…Cultured cells were fixed with 4% paraformaldehyde in 25 mM phosphate buffer (pH 7.4) for 30 min at room temperature. The procedure for immunostaining was essentially the same as in Kikuchi et al , 2005 [ 8 ]. Primary antibodies used in experiments were rabbit anti-rat growth hormone (GH; Dr. K. Wakabayashi, Gunma University, Gunma, Japan, dilution of 1:12,800), anti-ovine luteinizing hormone (LH) β subunit (Dr. K. Wakabayashi, dilution of 1:12,800), anti-rat prolactin (NIH, Bethesda, MD, USA, dilution of 1:12,800), anti-rat thyroid-stimulating hormone (TSH) β subunit (NIH, dilution of 1:3,200), anti-porcine adrenocorticotrophic hormone 1–39 (ACTH; Dr. Nakamura, Hokkaido University, Hokkaido, Japan, dilution of 1:3,200), and anti-S100B protein (DAKO, Glostrup, Denmark, dilution of 1:500).…”