Effects of Reserpinization, Surgical Denervation and in vitro Chemical Denervation with 6-Hydroxydopamine on the Contractile Response of Isolated Rabbit Ear Artery to Propranolol

1981 ◽  
Vol 18 (4-5) ◽  
pp. 153-160 ◽  
Author(s):  
Ralph E. Purdy ◽  
Donald W. Ashbrook ◽  
Diana E. Hurlbut ◽  
John P. Reidy ◽  
Robert E. Stratford ◽  
...  
Keyword(s):  
Contractile Response ◽  
Rabbit Ear Artery ◽  
Ear Artery ◽  
Rabbit Ear ◽  
Chemical Denervation ◽  
6 Hydroxydopamine

5-Hydroxytryptamine delays relaxation time of norepinephrine-induced vasoconstriction

1986 ◽  
Vol 250 (1) ◽  
pp. H121-H130 ◽  
Author(s):  
S. Manzini ◽  
C. A. Maggi ◽  
A. Meli
Keyword(s):  
K Channel ◽  
Rabbit Ear Artery ◽  
Vasoactive Agents ◽  
Cellular Mechanisms ◽  
Relaxation Kinetics ◽  
Remarkable Effect ◽  
Ear Artery ◽  
Rabbit Ear ◽  
6 Hydroxydopamine ◽  
Kinetics Of

The effect of low concentration of 5-hydroxytryptamine (5-HT; 0.03-0.3 microM) on cellular and extracellular Ca2+ -dependent norepinephrine (NE; 5 microM)-induced vasoconstriction was assessed in isolated perfused rabbit ear artery. The most remarkable effect of 5-HT is a concentration-dependent enhancement of the duration of the extracellular Ca2+ -dependent NE-induced vasoconstriction. This effect of 5-HT is still present in 6-hydroxydopamine-pretreated arteries and in the presence of deoxycorticosterone and is not mimicked by the K+ channel blocker tetraethylammonium. Administration of nifedipine (0.3 microM) and EDTA (1 mM) failed to antagonize 5-HT-induced prolongation of relaxation kinetics of extracellular Ca2+ -dependent NE-induced vasoconstriction. On the other hand, this phenomenon was abolished by caffeine (15 mM) and markedly reduced by dibutyryl cyclic AMP (3 mM). 5-HT (0.3 microM), but not NE (30-50 nM), enhanced the vasoconstriction elicited by caffeine (15 mM) that was procaine sensitive and unaffected by nifedipine. These results suggest that 5-HT prolonged relaxation kinetics of NE-induced vasoconstriction through an impairment of cellular mechanisms that decrease the myoplasmic level of free Ca2+. A similar mechanism could be of relevance for 5-HT enhancement of vascular smooth muscle responsiveness to vasoactive agents.

A novel response to propranolol: Contractile response in the isolated rabbit ear artery

Life Sciences ◽  
1980 ◽  
Vol 26 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Donald W. Ashbrook ◽  
Ralph E. Purdy ◽  
Diana E. Hurlbut ◽  
Leslie A. Rains ◽  
John P. Reidy ◽  
...  
Keyword(s):  
Contractile Response ◽  
Rabbit Ear Artery ◽  
Ear Artery ◽  
Rabbit Ear

Supersen sitivity to norepinephrine induced in vitro by crude Latrodectus mactans venom in the rabbit ear artery

Toxicon ◽  
1977 ◽  
Vol 15 (1) ◽  
pp. 71-74 ◽  
Author(s):  
R.P. Rothlin ◽  
J.Fernandez Pardal ◽  
M.M.Fernandez Pardal ◽  
J.E.B. Pinto
Keyword(s):  
Rabbit Ear Artery ◽  
Ear Artery ◽  
Rabbit Ear ◽  
Latrodectus Mactans

Distinction of NPY receptors in vitro and in vivo. I. NPY-(18-36) discriminates NPY receptor subtypes in vitro

1990 ◽  
Vol 259 (1) ◽  
pp. E131-E139 ◽  
Author(s):  
M. C. Michel ◽  
E. Schlicker ◽  
K. Fink ◽  
J. H. Boublik ◽  
M. Gothert ◽  
...  
Keyword(s):  
Serotonin Release ◽  
Model Systems ◽  
Receptor Subtypes ◽  
Rabbit Ear Artery ◽  
Partial Agonists ◽  
Npy Receptor ◽  
Ear Artery ◽  
Rabbit Ear ◽  
Hel Cells

We studied the possibility of multiple neuropeptide Y (NPY) receptor subtypes. NPY-stimulated Ca2+ mobilization in human erythroleukemia (HEL) cells was used to screen a number of NPY analogues. The potencies of three of these analogues [peptide YY (PYY), [D-Tyr-36]NPY, and NPY-(18-36)] were compared with that of NPY in the following model systems: Ca2+ mobilization and inhibition of adenosine 3',5'-cyclic monophosphate accumulation in HEL cells, potentiation of vasoconstriction in the isolated rabbit ear artery, reduction of cutaneous microvascular perfusion in the rat digit, and inhibition of [3H]serotonin release in rat brain. In each of the five models, PYY was a full agonist that exhibited a similar or slightly higher potency than NPY, whereas [D-Tyr-36]NPY and NPY-(18-36) were partial agonists with lower potencies: NPY-(18-36) had a lower potency and efficacy than [D-Tyr-36]NPY in HEL cells and the rabbit ear artery, but was more effective than [D-Tyr-36]NPY for constricting cutaneous microvasculature and inhibiting serotonin release. Because of its weak partial agonism, we also tested NPY-(18-36) as an antagonist of NPY-stimulated Ca2+ mobilization in HEL cells. NPY-(18-36) shifted the NPY concentration-response curve to the right with a KB affinity value of 297 nM. In summary, [D-Tyr-36]NPY and NPY-(18-36) are partial agonists, the relative potency of which varies between systems. These data demonstrate the presence of multiple NPY receptor subtypes. We propose a modified classification scheme of NPY receptor subtypes.

An ultrastructural analysis of the sympathetic innervation of the rabbit ear artery and middle cerebral artery and their branches

1992 ◽  
Vol 50 (1) ◽  
pp. 934-935
Author(s):  
John T. Dodge ◽  
John A. Bevan
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Sympathetic Innervation ◽  
Electrical Field Stimulation ◽  
Rabbit Ear Artery ◽  
Electrical Field ◽  
Functional Differences ◽  
Ear Artery ◽  
Rabbit Ear ◽  
Vascular Beds

Unlike many peripheral vascular beds, the sympathetic nervous system exerts little control on cerebral blood flow. The contractile response of isolated rabbit middle cerebral artery (MCA) segments to electrical field stimulation of its intramural nerves is less than in a similar-sized artery from the ear. This study was undertaken to characterize and compare the perivascular neuromuscular relationships and innervation density of similar-sized arteries varying in diameter from these two different regional arterial beds to see if there were structural correlates for these functional differences.

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