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Title: Pertussis toxin inhibits somatostatin-induced K/sup +/ conductance in human pituitary tumor cells

The effect of pertussis toxin on somatostatin-induced K/sup +/ current was examined in dissociated human pituitary tumor cells obtained from two acromegalic patients. Somatostatin-induced hyperpolarization or K/sup +/ current was observed in 20 of 23 cells in adenoma 1 and 10 of 11 cells in adenoma 2. After treatment with pertussis toxin for 24 h, these responses were completely suppressed (0/14 in adenoma, 1, 0/10 in adenoma 2). Spontaneous action potentials, K/sup +/, Na/sup +/, and Ca/sup 2 +/ currents were well preserved after pertussis toxin treatment. When crude membrane fraction was incubated with (/sup 32/P)NAD, a 41K protein was ADP-ribosylated by pertussis toxin. Hormone release was inhibited by somatostatin and this inhibition was blocked by pertussis toxin treatment.
Authors:
; ; ;
Publication Date:
OSTI Identifier:
6207940
Resource Type:
Journal Article
Resource Relation:
Journal Name: Am. J. Physiol.; (United States); Journal Volume: 253:1
Research Org:
Univ. of Tokyo School of Medicine (Japan)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; CELL MEMBRANES; BIOELECTRICITY; SOMATOSTATIN; RADIOIMMUNOASSAY; TOXINS; BIOLOGICAL EFFECTS; CATIONS; ELECTROPHORESIS; MAN; NAD; PHOSPHORUS 32; PITUITARY GLAND; POTASSIUM COMPOUNDS; PROTEINS; TUMOR CELLS; ALKALI METAL COMPOUNDS; ANIMAL CELLS; ANIMALS; ANTIGENS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BODY; CELL CONSTITUENTS; CHARGED PARTICLES; COENZYMES; DAYS LIVING RADIOISOTOPES; ELECTRICITY; ENDOCRINE GLANDS; GLANDS; IMMUNOASSAY; IMMUNOLOGY; IONS; ISOTOPE APPLICATIONS; ISOTOPES; LIGHT NUCLEI; MAMMALS; MATERIALS; MEMBRANES; NUCLEI; NUCLEOTIDES; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; ORGANS; PHOSPHORUS ISOTOPES; PRIMATES; RADIOASSAY; RADIOIMMUNOLOGY; RADIOISOTOPES; TOXIC MATERIALS; TRACER TECHNIQUES; VERTEBRATES 550201* -- Biochemistry-- Tracer Techniques