Parathyroid hormone-sensitive adenylate cyclase system in plasma membranes of rat liver

Journal Article · Mon Dec 01 04:00:00 EST 1980 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-107-6-2082· OSTI ID:6643945

Neuman, W F; Schneider, N

Purified plasma membranes were prepared from normal rat livers. These membranes were unable to degrade parathyroid hormone (PTH), bovine PTH-(1 to 84) (bPTH-(1 to 84)), or bPTH-(1 to 34). The entire molecule bPTH-(1 to 84) caused a marked activation of adenylate cyclase (cAMP production increased over 5-fold), with half-maximal stimulation at 6.9 x 10/sup -8/ M. The amino-terminal fragment bPTH-(1 to 34) was equipotent but gave a smaller maximal cAMP production. The human (h) amino acid sequence, hPTH-(1 to 34) was only weakly effective at a concentration of 10/sup -5/ M. A similar species specificity was shown with crude rat renal cortical membranes. Of a variety of ligands, only glucagon and 10/sup -3/ M F/sup -/ were cyclase activators in these liver plasma membranes. Binding of (/sup 125/I)iodo-bPTH by these membranes was fairly extensive but showed a saturation of binding only at high hormone concentrations (> 10/sup -6/ M). Clearly, cleavage of the intact molecule PTH-(1 to 84) is not required for activation of the adenylate cyclase system of liver membranes. It appears that two rat tissues, liver and kidney, exhibit some species specificity in cyclase activation, i.e. the hPTH-(1 to 34) (Niall sequence) is inactive.

• Research Organization: Univ. of Rochester Medical Center, NY
• OSTI ID: 6643945
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 107:6; ISSN ENDOA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ACTIVITY LEVELS
AMP
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BODY
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL ACTIVATION
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DYNAMIC FUNCTION STUDIES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
GLANDS
HORMONES
IN VITRO
IN VIVO
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
KINETICS
LABELLED COMPOUNDS
LIVER
MAMMALS
MEMBRANES
METABOLISM
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PARATHORMONE
PEPTIDE HORMONES
PHYSIOLOGY
QUANTITY RATIO
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
TRACER TECHNIQUES
VERTEBRATES