Autoradiographic Localization of Opioid and Spirodecanone Receptors in the Gerbil Hippocampus as Compared with the Rat Hippocampus

1988 ◽  
Vol 8 (4) ◽  
pp. 568-574 ◽  
Author(s):  
Hiroshi Onodera ◽  
Kyuya Kogure
Keyword(s):  
Opioid Receptor ◽  
Binding Sites ◽  
Cellular Localization ◽  
Neuronal Damage ◽  
Pyramidal Cells ◽  
Rat Hippocampus ◽  
High Concentration ◽  
Receptor Sites ◽  
Ca3 Neurons

Opioid ([3H]naloxone) and spirodecanone ([3H]spiperone) binding sites in the hippocampus were visualized in the Mongolian gerbil and in the rat using in vitro autoradiography. In the hippocampus, marked differences were noted in the stratum (sr.) pyramidale of the CA1 subfield where opioid and spirodecanone (assayed in the presence of mianserin and sulpiride) binding activities were very low in gerbils, but high in rats. Gerbils exhibited a high concentration of [3H]naloxone binding sites in the sr. pyramidale of the CA3 subfield, as observed in the rat. In addition, the gerbil has a very high opioid receptor density in the hilar region and in the sr. moleculare of the dentate gyrus. The cellular localization of opioid and spirodecanone receptor sites was studied in the rat hippocampus using selective neuronal damage to CA1 and CA3 neurons by means of ischemia and kainic acid treatment, respectively. The results suggest that the gerbil differs from the rat with respect to the characteristic pyramidal cells (spirodecanone binding site) and interneurons (opioid receptor) in the CA1 subfield of the hippocampus. Distinct localization of opioid and spirodecanone receptors in the gerbil provides a good model with which to investigate the electrophysiological and biochemical roles of opioid peptides and butyrophenone spirodecanone drugs.

Barbiturate protection against hypoxic neuronal damage in vitro

1986 ◽  
Vol 65 (2) ◽  
pp. 230-232 ◽  
Author(s):  
Peter G. Aitken ◽  
Steven J. Schiff
Keyword(s):  
Neuronal Damage ◽  
Pyramidal Cells ◽  
Perfusion Medium ◽  
Tissue Slices ◽  
Content Type ◽  
Ca1 Pyramidal Cells ◽  
Hippocampal Tissue ◽  
Barbiturate Protection ◽  
Fine Print

✓ Hippocampal tissue slices in vitro were exposed to periods of hypoxia of different durations. Addition of pentobarbital to the perfusion medium significantly increased the duration of hypoxia that was survived by CA1 pyramidal cells.

Praziquantel and the benzodiazepine Ro 11-3128 do not compete for the same binding sites in schistosomes

Parasitology ◽  
2007 ◽  
Vol 135 (1) ◽  
pp. 47-54 ◽  
Author(s):  
L. PICA-MATTOCCIA ◽  
A. RUPPEL ◽  
C. M. XIA ◽  
D. CIOLI
Keyword(s):  
Calcium Channel ◽  
Binding Sites ◽  
Calcium Influx ◽  
Cytochalasin D ◽  
The Other ◽  
Channel Blockers ◽  
Spastic Paralysis ◽  
Receptor Sites

SUMMARYThe benzodiazepine Ro 11-3128 (methyl-clonazepam) presents several similarities with praziquantel with regard to its anti-schistosomal mode of action, since both drugs cause spastic paralysis, calcium influx and tegumental disruption in the parasites. In order to know whether the two compounds share the same binding sites in the schistosomes, we performed in vivo and in vitro competition experiments. We took advantage of the fact that Ro 11-3128 is active against immature Schistosoma mansoni (whereas praziquantel is inactive), and praziquantel is active against S. japonicum (which is insensitive to Ro 11-3128). An excess of praziquantel did not inhibit the activity of Ro 11-3128 against immature S. mansoni and an excess of Ro 11-3128 did not inhibit the activity of praziquantel against S. japonicum, suggesting that the schistosome binding sites of the two drugs are different. On the other hand, cytochalasin D, an agent known to perturb – among other things – calcium channel function, was capable of inhibiting the schistosomicidal activity of both praziquantel and Ro 11-3128, thus adding another element of similarity between the two anti-schistosomal agents. A similar, albeit partial, inhibition of the schistosomicidal activity of the two drugs was exerted by some of the classical calcium channel blockers. Taken together, these results suggest that praziquantel and Ro 11-3128, although binding to different schistosome receptor sites, may use the same basic anti-schistosomal effector mechanisms.

scholarly journals Hormonal regulation of delta opioid receptor immunoreactivity in interneurons and pyramidal cells in the rat hippocampus

2011 ◽  
Vol 95 (2) ◽  
pp. 206-220 ◽  
Author(s):  
Tanya J. Williams ◽  
Annelyn Torres-Reveron ◽  
Jeanette D. Chapleau ◽  
Teresa A. Milner
Keyword(s):  
Opioid Receptor ◽  
Hormonal Regulation ◽  
Pyramidal Cells ◽  
Rat Hippocampus ◽  
Delta Opioid Receptor

A HIGH-AFFINITY BINDING SITE FOR THE ANTIOESTROGENS, TAMOXIFEN AND CI 628, IN IMMATURE RAT UTERINE CYTOSOL WHICH IS DISTINCT FROM THE OESTROGEN RECEPTOR

1981 ◽  
Vol 91 (1) ◽  
pp. 155-161 ◽  
Author(s):  
L. C. MURPHY ◽  
R. L. SUTHERLAND
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Oestrogen Receptor ◽  
Dissociation Constants ◽  
Significant Proportion ◽  
Immature Rat ◽  
High Affinity ◽  
Saturable Binding ◽  
Receptor Sites

A high-affinity, saturable antioestrogen binding site, which does not bind oestradiol, has been reported to exist in a number of oestrogen target tissues but not in the immature rat uterus. This study reports the results of a more thorough search for this site in immature rat uterine cytosol. When concentrations of uterine cytoplasmic oestrogen receptor were selectively depleted by translocation of 90–95% of the cytoplasmic oestrogen receptor to the nucleus, saturation analysis studies revealed that the antioestrogens, tamoxifen and CI 628, were bound to high-affinity, saturable binding sites which were present at about 2·5 times the concentration of the residual oestrogen receptor sites. Oestradiol could only partially inhibit the binding of tritiated antioestrogens to their saturable binding sites in this material indicating that a significant proportion of these sites were distinct from the oestrogen receptor sites. This was confirmed in experiments where oestrogen receptor sites were saturated in vitro with oestradiol and high-affinity, saturable sites for CI 628 and tamoxifen were still present. The CI 628 and tamoxifen had high affinity for these sites with dissociation constants of 1·0–1·6 nmol/l. These specific antioestrogen binding sites were present at about 5% of the concentration of oestrogen receptors in normal immature rat uterine cytosol which probably explains their previous lack of detection in this material.

Properties of Carbachol-Induced Oscillatory Activity in Rat Hippocampus

1997 ◽  
Vol 78 (5) ◽  
pp. 2631-2640 ◽  
Author(s):  
John H. Williams ◽  
Julie A. Kauer
Keyword(s):  
Ampa Receptor ◽  
Metabotropic Glutamate Receptors ◽  
Theta Rhythm ◽  
Pyramidal Cells ◽  
Rat Hippocampus ◽  
Oscillatory Activity ◽  
Membrane Hyperpolarization ◽  
Population Oscillation

Williams, John H. and Julie A. Kauer. Properties of carbachol-induced oscillatory activity in rat hippocampus. J. Neurophysiol. 78: 2631–2640, 1997. The recent resurgence of interest in carbachol oscillations as an in vitro model of theta rhythm in the hippocampus prompted us to evaluate the circuit mechanisms involved. In extracellular recordings, a regularly spaced bursting pattern of field potentials was observed in both CA3 and CA1 subfields in the presence of carbachol. Removal of the CA3 region abolished oscillatory activity observed in CA1, suggesting that the oscillatory generator is located in CA3. An α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX), blocked carbachol oscillations, indicating that AMPA receptor-mediated synaptic currents are necessary for the population oscillation. Moreover, the spread of oscillatory activity into CA1 required intact N-methyl-d-aspartate receptors. These data are more consistent with epileptiform bursting than with theta rhythm described in vivo. In the presence of carbachol, individual CA3 pyramidal cells exhibited a slow, rhythmic intrinsic oscillation that was not blocked by DNQX and that was enhanced by membrane hyperpolarization. We hypothesize that this slower oscillation is the fundamental oscillator that participates in triggering the population oscillation by exciting multiple synaptically connected CA3 neurons. γ-aminobutyric acid-A (GABAA) receptors are not necessary for carbachol to elicit synchronous CA3 field events but are essential to the bursting pattern observed. Neither GABABnor metabotropic glutamate receptors appear to be necessary for carbachol oscillations. However, both nicotinic and M1 and M3 muscarinic cholinergic receptors contribute to the generation of this activity. These results establish the local circuit elements and neurotransmitter receptors that contribute to carbachol-induced oscillations and indicate that carbachol-induced oscillations are fundamentally distinct from theta rhythm in vivo.

Two oxytocin-binding site subtypes in rat kidney: pharmacological characterization, ontogeny and localization by in vitro and in vivo autoradiography

1997 ◽  
Vol 153 (1) ◽  
pp. 49-59 ◽  
Author(s):  
M P Arpin-Bott ◽  
E Waltisperger ◽  
M J Freund-Mercier ◽  
M E Stoeckel
Keyword(s):  
Binding Sites ◽  
Cellular Localization ◽  
Rat Kidney ◽  
Distal Tubule ◽  
Macula Densa ◽  
Pharmacological Characterization ◽  
Henle's Loop ◽  
Semithin Sections

Abstract The localization of oxytocin (OT)-binding sites in the developing rat kidney and their pharmacological characterization were investigated by means of autoradiographic techniques. The cellular localization was studied by application of the histoautoradiographic technique to (1) frozen sections and semithin sections from kidney slices incubated in vitro in the presence of a 125I-labelled OT antagonist and (2) frozen and semithin sections from kidneys after in vivo systemic infusion of the radioligand. Pharmacological characteristics were determined in competition experiments by using quantitative film autoradiography. Specific OT-binding sites were first detected at embryonic day 17 (E17) in the cortex. At early stages up to postnatal days (PN30), the cortical OT-binding sites were highly concentrated on the juxta- and paraglomerular portion of the distal tubule; in the adult they were restricted to the macula densa. In the medulla, OT-binding sites were first detected at E19 when this region is forming; they were localized on the thin limb of Henle's loop. These data obtained by in vitro binding were confirmed by in vivo binding at PN30 which showed, in addition, the presence in one rat of OT-binding sites in the inner stripe of the outer medulla. At all stages examined (PN15 to PN90), cortical OT-binding sites had a higher selectivity for OT versus vasopressin (IC50=0·78 ± 0·04 nm and 8 ± 0·5 nm respectively at PN90) than medullary sites (IC50= 1·9 ± 0·27 nm and 2±1·13 nm respectively at PN90). These data suggest that the OT-binding sites of the macula densa and thin Henle's loop, detected in the rat kidney, represent two subtypes of OT receptors which could mediate distinct effects of OT on kidney function. Journal of Endocrinology (1997) 153, 49–59

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