In Vitro Uptake of Benzodiazepines by Rat Pineal Gland

As a part of a study aiming to characterize the physiological and pharmacological significance of the high affinity pineal benzodiazepine (BZP) binding sites reported previously, we examined the uptake of the BZP derivative 3H‐flunitrazepam (FNZP) by rat pineal glands in vitro. At 37 °C, 3H‐radioact...

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Publicado:	1984
Materias:	benzodiazepine uptake diurnal rhythms pineal gland superior cervical ganglionectomy benzodiazepine benzodiazepine receptor radioisotope animal cell central nervous system circadian rhythm drug accumulation drug receptor binding endocrine system flunitrazepam h 3 nonhuman pharmacokinetics pineal body rat Animal Biological Transport Cerebral Cortex Female Flunitrazepam Kinetics Organ Specificity Pineal Gland Rats Rats, Inbred Strains Receptors, GABA-A Support, Non-U.S. Gov't
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07423098_v1_n3_p207_Lowenstein http://hdl.handle.net/20.500.12110/paper_07423098_v1_n3_p207_Lowenstein
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_07423098_v1_n3_p207_Lowenstein
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spelling	paper:paper_07423098_v1_n3_p207_Lowenstein2023-06-08T15:44:42Z In Vitro Uptake of Benzodiazepines by Rat Pineal Gland benzodiazepine uptake diurnal rhythms pineal gland superior cervical ganglionectomy benzodiazepine benzodiazepine receptor radioisotope animal cell central nervous system circadian rhythm drug accumulation drug receptor binding endocrine system flunitrazepam h 3 nonhuman pharmacokinetics pineal body rat superior cervical ganglionectomy Animal Biological Transport Cerebral Cortex Female Flunitrazepam Kinetics Organ Specificity Pineal Gland Rats Rats, Inbred Strains Receptors, GABA-A Support, Non-U.S. Gov't As a part of a study aiming to characterize the physiological and pharmacological significance of the high affinity pineal benzodiazepine (BZP) binding sites reported previously, we examined the uptake of the BZP derivative 3H‐flunitrazepam (FNZP) by rat pineal glands in vitro. At 37 °C, 3H‐radioactivity was taken up by tissue up to a pineal/medium concentration of about 12, while at 0 °C the uptake amounted to only one‐third that at 37 °C. Reciprocal of uptake analyzed by Lineweaver‐Burk plots indicated apparent Km's of 1.74 and 1.45 μM, and Vmax's of 1.32 and 1.04 pmol per min per mg tissue, for control and superior cervical ganglionectomized rats, respectively, suggesting that the neural compartment does not participate significantly in 3H‐FNZP uptake. Cerebral cortex explants of similar size and weight as the pineal ones took up 3H‐FNZP to a maximum tissue/ medium concentration of about 2. Neither pineal nor cerebral cortex 3H‐radioactivity uptake exhibited significant changes as a function of time of day. A number of agents, including several BZP analogues, cocaine, desipramine, melatonin, fluoxetine, nomifensine, and dipiridamol, as well as changes in the ionic environment or metabolic inhibitors, did not affect 3H‐FNZP uptake significantly. Other tissues, such as liver, muscle, kidney, adrenal gland, or anterior pituitary, took up 3H‐radioactivity to tissue concentrations slightly lower than those of the cerebral cortex, suggesting that drug liposolubility accounted only to a limited extent for the high in vitro uptake detected in incubated pineals. Copyright © 1984, Wiley Blackwell. All rights reserved 1984 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07423098_v1_n3_p207_Lowenstein http://hdl.handle.net/20.500.12110/paper_07423098_v1_n3_p207_Lowenstein
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	benzodiazepine uptake diurnal rhythms pineal gland superior cervical ganglionectomy benzodiazepine benzodiazepine receptor radioisotope animal cell central nervous system circadian rhythm drug accumulation drug receptor binding endocrine system flunitrazepam h 3 nonhuman pharmacokinetics pineal body rat superior cervical ganglionectomy Animal Biological Transport Cerebral Cortex Female Flunitrazepam Kinetics Organ Specificity Pineal Gland Rats Rats, Inbred Strains Receptors, GABA-A Support, Non-U.S. Gov't
spellingShingle	benzodiazepine uptake diurnal rhythms pineal gland superior cervical ganglionectomy benzodiazepine benzodiazepine receptor radioisotope animal cell central nervous system circadian rhythm drug accumulation drug receptor binding endocrine system flunitrazepam h 3 nonhuman pharmacokinetics pineal body rat superior cervical ganglionectomy Animal Biological Transport Cerebral Cortex Female Flunitrazepam Kinetics Organ Specificity Pineal Gland Rats Rats, Inbred Strains Receptors, GABA-A Support, Non-U.S. Gov't In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
topic_facet	benzodiazepine uptake diurnal rhythms pineal gland superior cervical ganglionectomy benzodiazepine benzodiazepine receptor radioisotope animal cell central nervous system circadian rhythm drug accumulation drug receptor binding endocrine system flunitrazepam h 3 nonhuman pharmacokinetics pineal body rat superior cervical ganglionectomy Animal Biological Transport Cerebral Cortex Female Flunitrazepam Kinetics Organ Specificity Pineal Gland Rats Rats, Inbred Strains Receptors, GABA-A Support, Non-U.S. Gov't
description	As a part of a study aiming to characterize the physiological and pharmacological significance of the high affinity pineal benzodiazepine (BZP) binding sites reported previously, we examined the uptake of the BZP derivative 3H‐flunitrazepam (FNZP) by rat pineal glands in vitro. At 37 °C, 3H‐radioactivity was taken up by tissue up to a pineal/medium concentration of about 12, while at 0 °C the uptake amounted to only one‐third that at 37 °C. Reciprocal of uptake analyzed by Lineweaver‐Burk plots indicated apparent Km's of 1.74 and 1.45 μM, and Vmax's of 1.32 and 1.04 pmol per min per mg tissue, for control and superior cervical ganglionectomized rats, respectively, suggesting that the neural compartment does not participate significantly in 3H‐FNZP uptake. Cerebral cortex explants of similar size and weight as the pineal ones took up 3H‐FNZP to a maximum tissue/ medium concentration of about 2. Neither pineal nor cerebral cortex 3H‐radioactivity uptake exhibited significant changes as a function of time of day. A number of agents, including several BZP analogues, cocaine, desipramine, melatonin, fluoxetine, nomifensine, and dipiridamol, as well as changes in the ionic environment or metabolic inhibitors, did not affect 3H‐FNZP uptake significantly. Other tissues, such as liver, muscle, kidney, adrenal gland, or anterior pituitary, took up 3H‐radioactivity to tissue concentrations slightly lower than those of the cerebral cortex, suggesting that drug liposolubility accounted only to a limited extent for the high in vitro uptake detected in incubated pineals. Copyright © 1984, Wiley Blackwell. All rights reserved
title	In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
title_short	In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
title_full	In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
title_fullStr	In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
title_full_unstemmed	In Vitro Uptake of Benzodiazepines by Rat Pineal Gland
title_sort	in vitro uptake of benzodiazepines by rat pineal gland
publishDate	1984
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07423098_v1_n3_p207_Lowenstein http://hdl.handle.net/20.500.12110/paper_07423098_v1_n3_p207_Lowenstein
_version_	1768541616673390592

In Vitro Uptake of Benzodiazepines by Rat Pineal Gland

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