Augments Adrenergic Neurotransmission
نویسندگان
چکیده
Background We have observed persistent desensitization to exogenous norepinephrine after balloon injury. We postulated that this desensitization may be due to a local increase in the release of neuronal norepinephrine. Methods and Results New Zealand White rabbits underwent left iliac artery angioplasty; 4 weeks later, both iliac arteries were harvested. Maximal response to exogenous norepinephrine was reduced in injured compared with noninjured vessels (12.3+1.0 g versus 10.3±1.5 g; n=7, P=.056). By contrast, response to electrical stimulation (to induce neuronal norepinephrine release) was significantly greater in injured tissues (36±7% versus 14±3%; values expressed as percent of maximal contraction to exogenous norepinephrine; P=.025). Direct measurement of tissue norepinephrine revealed a threefold increase 4 weeks after injury (1236±410 versus 466±97 pg/mg; injured versus noninjured). To determine if desensitization to exogenous norepinephrine was due to a persistent increase in neuronal norepinephrine release, the
منابع مشابه
Mechanism of Action of the Thyroid Hormone on the Heart
SUMMARY The foliowing cardiac effects may be attributed to thyroxin: 1-Thyroxin augments all anaerobic processes in the body includ::ng the heart, and decreases the glycogen content of the heart ( 1, 2, 5, 27). The resistance of the heart to anoxia is increased in hyperthyroidism ( 25). 2- Thyroxin influences the cardiac weight and prevents cardiac atrophy (3, 8, 10, 11, 19, 20, 21, 30...
متن کاملReelin Mobilizes a VAMP7-Dependent Synaptic Vesicle Pool and Selectively Augments Spontaneous Neurotransmission
Reelin is a glycoprotein that is critical for proper layering of neocortex during development as well as dynamic regulation of glutamatergic postsynaptic signaling in mature synapses. Here, we show that Reelin also acts presynaptically, resulting in robust rapid enhancement of spontaneous neurotransmitter release without affecting properties of evoked neurotransmission. This effect of Reelin re...
متن کاملTwo functionally distinct alpha2-adrenergic receptors regulate sympathetic neurotransmission.
The sympathetic nervous system regulates cardiovascular function by activating adrenergic receptors in the heart, blood vessels and kidney. Alpha2-adrenergic receptors are known to have a critical role in regulating neurotransmitter release from sympathetic nerves and from adrenergic neurons in the central nervous system; however, the individual roles of the three highly homologous alpha2-adren...
متن کاملC-type natriuretic peptide neuromodulates independently of guanylyl cyclase activation.
Of the four endogenous members of the natriuretic peptide family, only atrial natriuretic peptide has been demonstrated to have neuromodulatory effects. This study compares the neuromodulatory effects of atrial natriuretic peptide and a recently identified natriuretic peptide, C-type natriuretic peptide, in the rabbit isolated vas deferens. The ability of these peptides to alter cyclic nucleoti...
متن کاملPresence of prejunctional D2-dopaminoceptors and α2-adrenoceptors on the cholinergic nerve of the common bile duct of guinea pig
On most adrenergic and cholinergic nerve terminals, prejunctional α-adrenoceptors belonging to the α2-subtype have been identified. Activation of these receptors will decrease the release of norepinephrine. It has been reported that several isolated tissue preparations contain prejunctional dopamine receptors, the stimulation of which inhibits neurotransmission. It has remained uncertain whethe...
متن کامل