Biomaterial Database

Ontogenetic development of isoproterenol subsensitivity of myocardial adenylate cyclase and beta-adrenergic receptors in spontaneously hypertensive rats. 1980

R C Bhalla, and R V Sharma, and S Ramanathan

[3H]Dihydroalprenolol binding and adenylate cyclase activity in the myocardial membranes of Kyoto Wistar normotensive rats and spontaneously hypertensive rats were compared at various stages of postnatal development ranging from 2 to 36 weeks. Basal as well as agonist-stimulated myocardial adenylate cyclase activity was consistently decreased in spontaneously hypertensive rats as compared to normotensive rats as early as 2 weeks of age with significant differences (P < 0.05) observed after 6 weeks of age. When results were expressed as percent stimulation over the basal activity, only isoproterenol plus GTP-stimulated enzyme activity was reduced by 25--30% in spontaneously hypertensive rats, suggesting a specific loss of stimulation by isoproterenol in hypertensive animals. The number of [3H]dihydroalprenolol binding sites of KD for dihydroalprenolol binding were comparable between spontaneously hypertensive and normotensive rats at 3, 6 and 12 weeks of age. The competition of isoproterenol with [3H]dihydroalprenolol for the specific binding sites showed that the affinity of isoproterenol binding was decreased 3--4-fold in spontaneously hypertensive compared with normotensive rats. With postnatal development in age, basal as well as agonist-stimulated activities decreased progressively in both spontaneously hypertensive and normotensive rats. Similarly, the number of [3H]dihydroalprenolol binding sites decreased with the development in age, whereas affinity of dihydroalprenolol binding increased up to 12 weeks of age. These results therefore suggest that adenylate cyclase activity and the number of beta-adrenergic receptors in rat heart, decrease with age and that in hypertension, specific decrease in isoproterenol stimulation of cyclase appears at all stages of development.

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D009929	Organ Size	The measurement of an organ in volume, mass, or heaviness.	Organ Volume,Organ Weight,Size, Organ,Weight, Organ
D011941	Receptors, Adrenergic	Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.	Adrenergic Receptors,Adrenoceptor,Adrenoceptors,Norepinephrine Receptor,Receptors, Epinephrine,Receptors, Norepinephrine,Adrenergic Receptor,Epinephrine Receptors,Norepinephrine Receptors,Receptor, Adrenergic,Receptor, Norepinephrine
D011943	Receptors, Adrenergic, beta	One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.	Adrenergic beta-Receptor,Adrenergic beta-Receptors,Receptors, beta-Adrenergic,beta Adrenergic Receptor,beta-Adrenergic Receptor,beta-Adrenergic Receptors,Receptor, Adrenergic, beta,Adrenergic Receptor, beta,Adrenergic beta Receptor,Adrenergic beta Receptors,Receptor, beta Adrenergic,Receptor, beta-Adrenergic,Receptors, beta Adrenergic,beta Adrenergic Receptors,beta-Receptor, Adrenergic,beta-Receptors, Adrenergic
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004082	Dihydroalprenolol	Hydrogenated alprenolol derivative where the extra hydrogens are often tritiated. This radiolabeled form of ALPRENOLOL, a beta-adrenergic blocker, is used to label the beta-adrenergic receptor for isolation and study.	1-((Methylethyl)amino)-3-(2-propylphenoxy)-2-propanol