Functional Characterization of the β-Adrenergic Receptor Subtypes Expressed by CA1 Pyramidal Cells in the Rat Hippocampus

2005 ◽  
Vol 314 (2) ◽  
pp. 561-567 ◽  
Author(s):  
Kristin L. Hillman ◽  
Van A. Doze ◽  
James E. Porter
Keyword(s):  
Adrenergic Receptor ◽  
Functional Characterization ◽  
Pyramidal Cells ◽  
Rat Hippocampus ◽  
Receptor Subtypes ◽  
Ca1 Pyramidal Cells

Functional Characterization of GABAA Receptors in Neonatal Hypothalamic Brain Slice

2002 ◽  
Vol 88 (4) ◽  
pp. 1655-1663 ◽  
Author(s):  
Ren-Qi Huang ◽  
Glenn H. Dillon
Keyword(s):  
Functional Characterization ◽  
Minor Component ◽  
Dehydroepiandrosterone Sulfate ◽  
Receptor Subtypes ◽  
Hypothalamic Neurons ◽  
Inhibitory Neurotransmitter ◽  
Old Rats ◽  
A Minor ◽  
Whole Cell Recordings

The hypothalamus influences a number of autonomic functions. The activity of hypothalamic neurons is modulated in part by release of the inhibitory neurotransmitter GABA onto these neurons. GABAA receptors are formed from a number of distinct subunits, designated α, β, γ, δ, ε, and θ, many of which have multiple isoforms. Little data exist, however, on the functional characteristics of the GABAA receptors present on hypothalamic neurons. To gain insight into which GABAA receptor subunits are functionally expressed in the hypothalamus, we used an array of pharmacologic assessments. Whole cell recordings were made from thin hypothalamic slices obtained from 1- to 14-day-old rats. GABAA receptor-mediated currents were detected in all neurons tested and had an average EC50 of 20 ± 1.6 μM. Hypothalamic GABAA receptors were modulated by diazepam (EC50 = 0.060 μM), zolpidem (EC50 = 0.19 μM), loreclezole (EC50 = 4.4 μM), methyl-6,7-dimethoxy-4-ethyl-β-carboline (EC50= 7.7 μM), and 5α-pregnan-3α-hydroxy-20-one (3α-OH-DHP). Conversely, these receptors were inhibited by Zn2+ (IC50 = 70.5 μM), dehydroepiandrosterone sulfate (IC50 = 16.7 μM), and picrotoxin (IC50 = 2.6 μM). The α4/6-selective antagonist furosemide (10–1,000 μM) was ineffective in all hypothalamic neurons tested. The results of our pharmacological analysis suggest that hypothalamic neurons express functional GABAA receptor subtypes that incorporate α1 and/or α2 subunits, β2 and/or β3 subunits, and the γ2 subunit. Our results suggest receptors expressing α3–α6, β1, γ1, and δ, if present, represent a minor component of functional hypothalamic GABAA receptors.

Functional characterization of basolateral and luminal dopamine receptors in rabbit CCD

2001 ◽  
Vol 281 (1) ◽  
pp. F114-F122 ◽  
Author(s):  
Osamu Saito ◽  
Yasuhiro Ando ◽  
Eiji Kusano ◽  
Yasushi Asano
Keyword(s):  
Receptor Agonist ◽  
Collecting Duct ◽  
Functional Characterization ◽  
Receptor Subtypes ◽  
Cortical Collecting Duct ◽  
Basolateral Side ◽  
Skf 81297 ◽  
Transepithelial Voltage ◽  
Specific Antagonist

Previous studies reported the existence of both D1- and D2-like receptors in the cortical collecting duct (CCD). However, especially with regard to natriuresis, it remains controversial. In the present study, rabbit CCD was perfused to characterize the receptor subtypes responsible for the tubular actions. Basolateral dopamine (DA) induced a dose-dependent depolarization of transepithelial voltage. Basolateral domperidone, a D2-like receptor antagonist, abolished depolarization, whereas SKF-81297, a D1-like receptor agonist, showed no significant change. In addition, bromocriptine, a D2-like receptor agonist, also caused depolarization, whereas SKF-81297, a D1-like receptor agonist, did not depolarize significantly. Moreover, RBI-257, a D4-specific antagonist, reversed the basolateral DA-induced depolarization. In contrast to the basolateral side, luminal DA caused depolarization via a D1-like receptor; however the change was less than that for basolateral DA. For further evaluation, 22Na+ flux ( J Na) was measured to confirm the effect of DA on Na+ transport. Basolateral DA also caused a suppression of J Na, and this reaction was abolished by domperidone. These results suggested that the basolateral D2-like receptor is mainly responsible for the natriuretic action of DA in rabbit CCD.

Control of arteriovenous anastomoses in rabbit ear model of digital perfusion

1996 ◽  
Vol 271 (5) ◽  
pp. H2007-H2013
Author(s):  
D. C. Pollock ◽  
Z. Li ◽  
L. A. Koman ◽  
E. S. Gordon ◽  
T. L. Smith
Keyword(s):  
Adrenergic Receptor ◽  
Receptor Subtypes ◽  
Arteriovenous Anastomoses ◽  
Cold Intolerance ◽  
Cutaneous Microcirculation ◽  
Rabbit Ear ◽  
New Zealand White Rabbits ◽  
Initial Characterization ◽  
Hands And Feet

The arteriovenous anastomoses (AVA) of the cutaneous microcirculation of the hands and feet are fundamental determinants of thermoregulatory blood flow and may be involved in cold intolerance. These direct microvascular studies are an initial characterization of adrenergic receptor subtypes participating in control of AVA in the ears of anesthetized male New Zealand White rabbits. Adrenergic alpha 1-stimulation with phenylephrine produced AVA constriction, whereas terazosin (an alpha 1-antagonist) produced dilation and attenuated the responses to phenylephrine. Adrenergic alpha 2-stimulation with UK-14304 produced constriction of the AVA, whereas atipamezole (an alpha 2-antagonist) produced dilation and attenuated the responses to UK-14304. When equimolar concentrations of antagonists were studied, the AVA dilation produced by alpha 2-blockade was greater than that produced by alpha 1-blockade. Norepinephrine (a mixed alpha 1- and alpha 2-agonist) also produced vasoconstriction, which was attenuated by both prazosin (an alpha 1-antagonist) and atipamezole. In summary, 1) AVA contain a heterogeneous mixture of both alpha 1- and alpha 2-receptors, and 2) alpha 2-receptors may have a greater influence than alpha 1-receptors on overall tone in AVA.

Cannabinoid receptor activation in CA1 pyramidal cells in adult rat hippocampus

2000 ◽  
Vol 863 (1-2) ◽  
pp. 120-131 ◽  
Author(s):  
M.Todd Kirby ◽  
Robert E Hampson ◽  
Sam A Deadwyler
Keyword(s):  
Cannabinoid Receptor ◽  
Pyramidal Cells ◽  
Receptor Activation ◽  
Rat Hippocampus ◽  
Adult Rat ◽  
Ca1 Pyramidal Cells

scholarly journals Purification and functional characterization of β-adrenergic receptor kinase expressed in insect cells

FEBS Letters ◽  
1993 ◽  
Vol 324 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Peter Sohlemann ◽  
Mirko Hekman ◽  
Claudia Buchen ◽  
John S. Elce ◽  
Martin J. Lohse
Keyword(s):  
Adrenergic Receptor ◽  
Insect Cells ◽  
Functional Characterization ◽  
Receptor Kinase
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