Effect of phorbol myristate acetate on secretion of parathyroid hormone

Journal Article · Fri Jan 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6938616

Morrissey, J J ^[1]

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1. Washington Univ. School of Medicine, St. Louis, MO (USA)

The influence of phorbol myristate acetate (PMA), an activator of protein kinase c, on the secretion of parathyroid hormone from collagenase-dispersed bovine parathyroid cells was tested. The cells were incubated at low or high concentrations of calcium in the medium, and the hormone secreted into the medium was measured by a radioimmunoassay that recognizes both intact and C-terminal fragments of hormone. A stimulatory effect of PMA at high calcium, seen at PMA concentrations as low as 1.6 nM, did not occur with a biologically inactive 4{alpha}-isomer of phorbol ester, and was independent of changes in cellular adenosine 3{prime},5{prime}-cyclic monophosphate levels. Examination of {sup 32}P-labeled phosphoproteins by two-dimensional gel electrophoresis revealed acidic proteins of {approximately}20,000 and 100,000 Da that were phosphorylated at low and high calcium + 1.6 {mu}M PMA but not at high calcium alone. The protein kinase c activity associated with the membrane fraction of parathyroid cells significantly decreased 40% when the cells were incubated at high vs. low calcium. The data suggest that calcium may regulate parathyroid hormone secretion through changes in protein kinase c activity of the membrane fraction of the cell and protein phosphorylation.

• OSTI ID: 6938616
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
560300 -- Chemicals Metabolism & Toxicology
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOASSAY
BIOCHEMISTRY
BIOLOGICAL EFFECTS
CALCIUM COMPOUNDS
CARBON 14 COMPOUNDS
CARCINOGENS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
ENZYMES
ESTERS
HORMONES
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PARATHORMONE
PEPTIDE HORMONES
PHORBOL ESTERS
PHOSPHOPROTEINS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RADIOISOTOPES
THYROID CELLS
TRACER TECHNIQUES
TRANSFERASES