Adrenergic agonists
Adrenergic agonists
overview The adrenergic drugs affect receptor that are stimulated by norepinephrine or epinephrine
overview ◼ The adrenergic drugs affect receptor that are stimulated by norepinephrine or epinephrine
The adrenergic neuron Adrenergic neurons release norepinephrine as the neurotransmitter. CNS,and between ganglia and the effector organs in sympathetic nervous system
The adrenergic neuron ◼ Adrenergic neurons release norepinephrine as the neurotransmitter. ◼ CNS, and between ganglia and the effector organs in sympathetic nervous system
Nicotinic Nicotinic rec台ptoU receptor Adrenal medulla 三pinephrine released Norepinephrine into the blood Adrenergic Adrenergic receptor receptor Effector organs Figure 6.2 Sites of actions of adrenergic agonists
Neurotransmission at adrenergic neurons Synthesis of norepiephrine Storage of norepiephrine in vesicles Release of norepiephrine ■Binding by receptor Removal of norepiephrine Potential fates of recaptured norepiephrine
Neurotransmission at adrenergic neurons ◼ Synthesis of norepiephrine ◼ Storage of norepiephrine in vesicles ◼ Release of norepiephrine ◼ Binding by receptor ◼ Removal of norepiephrine ◼ Potential fates of recaptured norepiephrine
1 SYNTHESIS OF NOREPINEPHRINE ·dra8 m UPTAKE INTO STORAGE VESICLES MAO美 56ote 。Tb22te8ae8 MAO RELEASE OF NEUROTRANSMITTER unretyilum REMOVAL OF NOREPINEPHRINE apidlyr eake。nmpn mt。 Catechol-O COM SYNAPTIC METABOLISM SPACE INTRACELLULAR RESPONSE e6.3 esis and release of norepinephrine from the adrenergic neuron
Adrenergic receptor a,B were initially identified on the basis of their responses the adrenergic agonists,epinephrine,norepinephrine, isoproterenol ■ a receptors have a higher affinity for phenylephrine.The drug clonidine selectively binds to a2 receptors
Adrenergic receptor ◼ , were initially identified on the basis of their responses the adrenergic agonists, epinephrine, norepinephrine, isoproterenol ◼ 1 receptors have a higher affinity for phenylephrine. The drug clonidine selectively binds to 2 receptors
A x Adrenoceptors a Receptor BB Adrenoceptors a aflinily Figure 6.4 Types of adrenergic receptors
a1 receptors these receptors are present on the postsynaptic membrane of the effector organs.G-protein coupling
1 receptors ◼ these receptors are present on the postsynaptic membrane of the effector organs. G-protein coupling
areceptors Located primarily on the presynaptic nerve endings and on other cells. The stimulation of the apreceptors causes feedback inhibition of the ongoing release of norepinephrine from the stimulated adrenergic neuron
2 receptors ◼ Located primarily on the presynaptic nerve endings and on other cells. ◼ The stimulation of the 2 receptors causes feedback inhibition of the ongoing release of norepinephrine from the stimulated adrenergic neuron