PICK1 deficiency leads to loss and altered localization of DCVs in the pituitary.

<p>(A) PICK1 is expressed in GH-producing cells of the pituitary. Confocal images of 15 µm slices from the pituitary of WT (+/+) (top) and PICK1-deficient mice (−/−) (bottom), immunostained for PICK1 (green) and GH (red). Insets show cells with characteristic intense arc-shaped distribution of GH and partial overlap with PICK1. Scale bar, 10 µm. Pictures are representative of stainings of seven pituitaries from WT and PICK1-deficient mice. (B) The number of DCVs is reduced in pituitary cells from PICK1-deficient mice. Transmission electron micrographs of uranyl acetate and lead citrate-stained ultrathin slices from the pituitary of WT (+/+) (top) and PICK1-deficient mice (−/−) (bottom). Scale bars, left, 20 µm. Pictures are representative of several pictures from five WT (+/+) and four PICK1-deficient (−/−) mice. (C) Quantification of the number of DCVs in 26 cells from WT (+/+) and 29 cells from PICK1-deficient (−/−) mice. **Average significantly different from control, <i>p</i> = 0.0022 in Student's <i>t</i> test. (D) Size distribution of DCVs in GH cells of the pituitary is unaltered in PICK1-deficient mice. The data show the relative frequency of different sizes of DCV in cells from PICK1-deficient mice (black) (<i>n</i> = 3,798) and in cells from WT mice (white) (<i>n</i> = 7,021).