Biomaterial Database

Stimulation of rat and cat heart adenylate cyclase by triiodothyronine in the presence of 5'-guanylylimidodiphosphate. 1976

L Will-Shahab, and A Wollenberger, and I Küttner

Adenylate cyclase activity in particulate preparations from the myocardium of rats and cats was unaffected by 3,3',5-triiodo-L-thyronine (L-T3) added in the absence of, or together with, 5-guanylylimidodiphosphate (Gpp(NH)p), a potent activator of the enzyme. Preincubation of the heart particles with Gpp(NH)p made the cyclase sensitive to L-T3 which then caused, in concentrations of 10(-8) M and higher, additional increases in enzyme activity up to about 50 per cent above the Gpp(NH)p-stimulated level. Similar effects after (GPP(NH)p treatment were produced by low concentrations of 3,3',5'-triiodo-L-thyronine (reverse T3) and 3,3',5-triiodo-D-thyronine, whereas diiodo-tyrosine, 3,5-diiodo-L-thyronine, and 3'-isopropyl-3,5-diiodo-L-thyronine were without significant effect. The stimulatory action of L-T3 on cardiac adenylate cyclase pretreated with Gpp(NH)p may help to explain some of the acute effects of thyroid hormones on the heart that have been reported in the literature.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships