Cosecretion of secretory protein-I and parathormone by dispersed bovine parathyroid cells

Journal Article · Mon Feb 01 04:00:00 EST 1982 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-110-2-625· OSTI ID:5578865

Cohn, D V ^[1]; Morrissey, J J; Shofstall, R E; Chu, L L.H.

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1. Veterans Administration Medical Center, Kansas City, MO

A RIA with a minimal sensitivity of 0.5 ng protein was developed for the measurement of bovine secretory protein-I (SP-I). With this assay and a previously established RIA for parathormone, the secretion and cell content of SP-I and parathormone were determined in dispersed bovine parathyroid cells. SP-I and parathormone were secreted in linear fashion over a 2-h period. The net secretion of both of these proteins diminished progressively as the concentration of calcium was raised from 0.25 mM to 3.0 mM. The molar ratio for the secreted proteins and those remaining in the cell varied from experiment to experiment but on average was 0.70 +/- 0.07 for the secreted proteins and 0.47 +/- 0.03 for the cellular proteins. Possible explanations for the difference in the ratio of SP-I to parathormone between cellular and secreted proteins include 1) a preferential secretion of SP-I; 2) a preferential intracellular degradation of SP-I; 3) a preferential postsecretory degradation of parathormone, or 4) differential affinities of potential fragments of either or both proteins for their antisera. These results suggest that SP-I and parathormone bear close but not identical metabolic and secretory fates.

• OSTI ID: 5578865
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 110:2; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL FUNCTIONS
BODY
CARBOHYDRATES
CATTLE
COWS
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
FUNCTIONS
GLANDS
GLUCOPROTEINS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PARATHORMONE
PARATHYROID GLANDS
PEPTIDE HORMONES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOISOTOPES
RUMINANTS
SACCHARIDES
SECRETION
TRACER TECHNIQUES
VERTEBRATES