Developmental changes in the role of a pertussis toxin sensitive guanine nucleotide binding protein in the rat cardiac alpha sub 1 -adrenergic system

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7117896

Han, H M

During development, the cardiac alpha{sub 1}-adrenergic chronotropic response changes from positive in the neonate to negative in the adult. This thesis examined the possibility of a developmental change in coupling of a PT-sensitive G-protein to the alpha{sub 1}-adrenergic receptor. Radioligand binding experiments performed with the iodinated alpha{sub 1}-selective radioligand ({sup 125}I)-I-2-({beta}-(4-hydroxphenyl)ethylaminomethyl)tetralone (({sup 125}I)-IBE 2254) demonstrated that the alpha{sub 1}-adrenergic receptor is coupled to a G-protein in both neonatal and adult rat hearts. However, in the neonate the alpha{sub 1}-adrenergic receptor is coupled to a PT-insensitive G-protein, whereas in the adult the alpha{sub 1}-adrenergic receptor is coupled to both a PT-insensitive and a PT-sensitive G-protein. Consistent with the results from binding experiments, PT did not have any effect on the alpha{sub 1}-mediated positive chronotropic response in the neonate, whereas in the adult the alpha{sub 1}-mediated negative chronotropic response was completely converted to a positive one after PT-treatment. This thesis also examined the possibility of an alteration in coupling of the alpha{sub 1}-adrenergic receptor to its effector under certain circumstances such as high potassium (K{sup +}) depolarization in nerve-muscle (NM) co-cultures, a system which has been previously shown to be a convenient in vitro model to study the mature inhibitory alpha{sub 1}-response.

• Research Organization: Columbia Univ., New York, NY (USA)
• OSTI ID: 7117896
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
PROTEINS
BIOLOGICAL FUNCTIONS
RECEPTORS
BIOCHEMICAL REACTION KINETICS
SYMPATHOMIMETICS
AGE DEPENDENCE
GUANINE
HEART
IODINE 125
RATS
TOXINS
TRACER TECHNIQUES
AMINES
ANIMALS
ANTIGENS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
FUNCTIONS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MATERIALS
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PURINES
RADIOISOTOPES
REACTION KINETICS
RODENTS
TOXIC MATERIALS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques