PK 11195, an antagonist of peripheral type benzodiazepine receptors, modulates BAY K8644 sensitive but not β- or H2-receptor sensitive voltage operated calcium channels in the guinea pig heart

Life Sciences ◽  
1986 ◽  
Vol 39 (4) ◽  
pp. 329-339 ◽  
Author(s):  
M. Mestre ◽  
T. Carriot ◽  
G. Néliat ◽  
A. Uzan ◽  
C. Renault ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Calcium Channels ◽  
Benzodiazepine Receptors ◽  
Guinea Pig Heart ◽  
H2 Receptor ◽  
Peripheral Type ◽  
Voltage Operated Calcium Channels

Interactions between peripheral-type benzodiazepine receptor ligands and an activator of voltage-operated calcium channels

1990 ◽  
Vol 68 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Gordon T. Bolger ◽  
Shlomo Abraham ◽  
Nissim Oz ◽  
Ben Avi Weissman
Keyword(s):  
Myocardial Ischemia ◽  
Guinea Pig ◽  
Calcium Channels ◽  
Benzodiazepine Receptor ◽  
Bay K 8644 ◽  
Organ Bath ◽  
Arterial Blood ◽  
Peripheral Type ◽  
Guinea Pig Atrium ◽  
Voltage Operated Calcium Channels

The effects of the peripheral-type benzodiapine receptor (PBR) ligands Ro 5-4864 and PK 11195 were studied in the spontaneously beating guinea pig atrium and in a model for myocardial ischemia in the rat. In the former, Bay K 8644 produced positive chronotropic and inotropic responses; intracarotid administration of this agonist (5 or 10 μg kg−1) to anesthetized rats elicited a transient increase in mean arterial blood pressure accompanied by alterations in the ECG pattern. Ro 5-4864 and PK 11195 (10 μM) completely blocked the positive chronotropic effect of Bay K 8644 in the atrium, PK 11209, a structural analog of PK 11195 with a low affinity for PBR, was inactive, and the central benzodiazepine receptor ligand clonazepam had a marginal effect. Ro 5-4864 potentiated whereas PK 11195 inhibited the myocardial ischemia produced by Bay K 8644 in the rat. Furthermore, PK 11195 blocked the combined response to Bay K 8644 and Ro 5-4864. Addition of Ro 5-4864 (10 μM) to the organ bath potentiated the inotropic effect of Bay K 8644 in the atria; PK 11195 at the same concentration inhibited this effect. Clonazepam and PK 11209 were both inactive in this regard. Nifedipine, a potent calcium channel antagonist, competely blocked the inotropic and chronotropic responses to Bay K 8644. PK 11195 and Ro 5-4864 did not affect this action. These findings strongly suggest that there is a functional association between PBR and voltage-operated calcium channels in the guinea pig atrium and rat cardiovascular system.Key words: peripheral benzodiazepine receptors, dihydropyridines, voltage-operated calcium channels, Bay K 8644, heart.

Characterization of the effects of AHN 086, an irreversible ligand of "peripheral" benzodiazepine receptors, on contraction in guinea-pig atria and ileal longitudinal smooth muscle

1989 ◽  
Vol 67 (2) ◽  
pp. 126-134 ◽  
Author(s):  
G. T. Bolger ◽  
A. H. Newman ◽  
K. C. Rice ◽  
H. W. M. Lueddens ◽  
A. S. Basile ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Calcium Channels ◽  
Benzodiazepine Receptors ◽  
Significant Inhibition ◽  
Bay K 8644 ◽  
Longitudinal Smooth Muscle ◽  
Peripheral Benzodiazepine Receptors ◽  
Inotropic Responses ◽  
Guinea Pig Atria

The effects of AHN 086 and its reversibly acting structural analogue Ro 5-4864 were studied in the spontaneously beating guinea-pig atria and field-stimulated guinea-pig ileal longitudinal smooth muscle in the presence and absence of dihydropyridine calcium channel modulators. The treatment of guinea-pig atria with AHN 086 followed by extensive washing did not alter contraction. However, AHN 086 (0.5 μM) potentiated (88%) the positive inotropic responses by BAY K 8644, an effect that was not reversed by extensive washing of the tissue. Higher concentrations of AHN 086 (> 2 μM) irreversibly inhibited the intropic, but not the chronotropic responses to BAY K 8644, nifedipine, and isoproterenol. Ro 5-4864 (10 μM) produced a reversible enhancement of the inotropic responses and block of the chronotropic responses to BAY K 8644. In guinea-pig ileal longitudinal smooth muscle, both AHN 086 and Ro 5-4864 reversibly inhibited field-stimulated contractions. Neither Ro 5-4864 nor AHN 086 affected the ability of nifedipine to inhibit field-stimulated contractions of ileal longitudinal smooth muscle. Treatment of intact atria with 5 μM AHN 086 followed by extensive washing resulted in a significant inhibition (30–50%) of [3H]Ro 5-4864 binding to peripheral benzodiazepine receptors and of [3H]nitrendipine binding to voltage-operated calcium channels, but did not affect [3H]dihydroalprenolol binding to β-adrenergic receptors on atrial membranes. The same treatment applied to intact ileal longitudinal smooth muscle affected neither [3H] (−)-quinuclidinyl benzilate binding to muscarine receptors nor [3H]nitrendipine binding, but did result in a significant inhibition (30–50%) of [3H]Ro 5-4864 binding to ileal longitudinal smooth muscle membranes. The pharmacology of AHN 086 suggests that there is a different relationship between peripheral benzodiazepine receptors and voltage-operated calcium channels in guinea-pig atria and ileal longitudinal smooth muscle.Key words: calcium channels, peripheral benzodiazepine receptors, dihydropyridines, benzodiazepines, dihydropyridine binding sites.

Peripheral type benzodiazepine receptors and response to adenosine on the guinea-pig isolated trachea

1990 ◽  
Vol 3 (3) ◽  
pp. 137-144 ◽  
Author(s):  
C. Advenier ◽  
P. Devillier ◽  
M. Blanc ◽  
J.P. Gnassounou
Keyword(s):  
Guinea Pig ◽  
Benzodiazepine Receptors ◽  
Isolated Trachea ◽  
Peripheral Type

Electrophysiological and pharmacological evidence that peripheral type benzodiazepine receptors are coupled to calcium channels in the heart

Life Sciences ◽  
1985 ◽  
Vol 36 (4) ◽  
pp. 391-400 ◽  
Author(s):  
M. Mestre ◽  
T. Carriot ◽  
C. Belin ◽  
A. Uzan ◽  
C. Renault ◽  
...  
Keyword(s):  
Calcium Channels ◽  
Benzodiazepine Receptors ◽  
Peripheral Type

Capsaicin inhibits the voltage-operated calcium channels intracellularly in the antral circular myocytes of guinea-pig stomach

Life Sciences ◽  
2001 ◽  
Vol 68 (21) ◽  
pp. 2347-2360 ◽  
Author(s):  
Jae Hoon Sim ◽  
Young Chul Kim ◽  
Sung Joon Kim ◽  
Sang Jin Lee ◽  
Suk Hyo Suh ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Calcium Channels ◽  
Guinea Pig Stomach ◽  
Voltage Operated Calcium Channels

Mitochondrial Oxidation of p-N, N-Dimethylamino-β-Phenethylamine (DAPA)

1975 ◽  
Vol 33 ◽  
pp. 458-459
Author(s):  
W. Allen Shannon ◽  
Hannah L. Wasserkrug ◽  
andArnold M. Seligman
Keyword(s):  
Guinea Pig ◽  
Oxidase Activity ◽  
Amine Oxidase ◽  
Histochemical Demonstration ◽  
Guinea Pig Heart ◽  
Pig Kidney ◽  
Cytoplasmic Vacuoles ◽  
Liver And Kidney ◽  
Mitochondrial Oxidation ◽  
Amine Oxidase Activity

The synthesis of a new substrate, p-N,N-dimethylamino-β-phenethylamine (DAPA)3 (Fig. 1) (1,2), and the testing of it as a possible substrate for tissue amine oxidase activity have resulted in the ultracytochemical localization of enzyme oxidase activity referred to as DAPA oxidase (DAPAO). DAPA was designed with the goal of providing an amine that would yield on oxidation a stronger reducing aldehyde than does tryptamine in the histochemical demonstration of monoamine oxidase (MAO) with tetrazolium salts.Ultracytochemical preparations of guinea pig heart, liver and kidney and rat heart and liver were studied. Guinea pig kidney, known to exhibit high levels of MAO, appeared the most reactive of the tissues studied. DAPAO reaction product appears primarily in mitochondrial outer compartments and cristae (Figs. 2-4). Reaction product is also localized in endoplasmic reticulum, cytoplasmic vacuoles and nuclear envelopes (Figs. 2 and 3) and in the sarcoplasmic reticulum of heart.

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