Regulation of glycogen content in rat pineal gland by norepinephrine

Eliseo Eugenin, Claudia G. Sáez, Gladys Garcés, Juan C. Sáez

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

In the rat pineal gland the glycogen stores were cytochemically localized in astrocytes and pinealocytes. Moreover, it was found that norepinephrine (NE) induced a time- and concentration-dependent reduction in pineal glycogen content and yielded lactic acid. The NE effect was prevented by blocking α1- but not α2 or β-adrenoceptors. Activation of α2- adrenoceptors induced a small decrease in glycogen levels that could have pre- and postsynaptic components. Activation of β-adrenoceptors with 10- 12-10-3 M isoproterenol (ISO) induced a bell shape concentration- response curve, presumably due to desensitization, since the response induced by 10-4 M ISO was greater with shorter period of stimulation. On the other hand, activation of α1-adrenoceptors with 10-12-10-3 M phenylephrine (PHN) induced a hyperbolic concentration-response curve with a maximum at concentrations above 10-8 M. Moreover, treatment with ISO drastically reduced the response induced by PHN concentrations lower but not higher than 10-6 M, favoring a concentration-dependent response between 10-6 and 10- 4 M PHN, similar to that induced by equimolar NE concentrations. Thus, the NE-induced reduction in glycogen content of the rat pineal gland is mainly mediated by α-adrenoceptors and modulated by intracellular mechanisms by β- adrenoceptors.

Original languageEnglish (US)
Pages (from-to)34-41
Number of pages8
JournalBrain Research
Volume760
Issue number1-2
DOIs
StatePublished - Jun 20 1997
Externally publishedYes

Fingerprint

Pineal Gland
Glycogen
Adrenergic Receptors
Norepinephrine
Phenylephrine
Isoproterenol
Astrocytes
Lactic Acid

Keywords

  • Adrenoceptor
  • Desensitization
  • Epiphysis cerebri
  • Glycogen
  • Lactic acid
  • Norepinephrine

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

Cite this

Regulation of glycogen content in rat pineal gland by norepinephrine. / Eugenin, Eliseo; Sáez, Claudia G.; Garcés, Gladys; Sáez, Juan C.

In: Brain Research, Vol. 760, No. 1-2, 20.06.1997, p. 34-41.

Research output: Contribution to journalArticle

Eugenin, Eliseo ; Sáez, Claudia G. ; Garcés, Gladys ; Sáez, Juan C. / Regulation of glycogen content in rat pineal gland by norepinephrine. In: Brain Research. 1997 ; Vol. 760, No. 1-2. pp. 34-41.
@article{74e1b1259f3c44f48396fdf9190ebad0,
title = "Regulation of glycogen content in rat pineal gland by norepinephrine",
abstract = "In the rat pineal gland the glycogen stores were cytochemically localized in astrocytes and pinealocytes. Moreover, it was found that norepinephrine (NE) induced a time- and concentration-dependent reduction in pineal glycogen content and yielded lactic acid. The NE effect was prevented by blocking α1- but not α2 or β-adrenoceptors. Activation of α2- adrenoceptors induced a small decrease in glycogen levels that could have pre- and postsynaptic components. Activation of β-adrenoceptors with 10- 12-10-3 M isoproterenol (ISO) induced a bell shape concentration- response curve, presumably due to desensitization, since the response induced by 10-4 M ISO was greater with shorter period of stimulation. On the other hand, activation of α1-adrenoceptors with 10-12-10-3 M phenylephrine (PHN) induced a hyperbolic concentration-response curve with a maximum at concentrations above 10-8 M. Moreover, treatment with ISO drastically reduced the response induced by PHN concentrations lower but not higher than 10-6 M, favoring a concentration-dependent response between 10-6 and 10- 4 M PHN, similar to that induced by equimolar NE concentrations. Thus, the NE-induced reduction in glycogen content of the rat pineal gland is mainly mediated by α-adrenoceptors and modulated by intracellular mechanisms by β- adrenoceptors.",
keywords = "Adrenoceptor, Desensitization, Epiphysis cerebri, Glycogen, Lactic acid, Norepinephrine",
author = "Eliseo Eugenin and S{\'a}ez, {Claudia G.} and Gladys Garc{\'e}s and S{\'a}ez, {Juan C.}",
year = "1997",
month = "6",
day = "20",
doi = "10.1016/S0006-8993(97)00273-4",
language = "English (US)",
volume = "760",
pages = "34--41",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Regulation of glycogen content in rat pineal gland by norepinephrine

AU - Eugenin, Eliseo

AU - Sáez, Claudia G.

AU - Garcés, Gladys

AU - Sáez, Juan C.

PY - 1997/6/20

Y1 - 1997/6/20

N2 - In the rat pineal gland the glycogen stores were cytochemically localized in astrocytes and pinealocytes. Moreover, it was found that norepinephrine (NE) induced a time- and concentration-dependent reduction in pineal glycogen content and yielded lactic acid. The NE effect was prevented by blocking α1- but not α2 or β-adrenoceptors. Activation of α2- adrenoceptors induced a small decrease in glycogen levels that could have pre- and postsynaptic components. Activation of β-adrenoceptors with 10- 12-10-3 M isoproterenol (ISO) induced a bell shape concentration- response curve, presumably due to desensitization, since the response induced by 10-4 M ISO was greater with shorter period of stimulation. On the other hand, activation of α1-adrenoceptors with 10-12-10-3 M phenylephrine (PHN) induced a hyperbolic concentration-response curve with a maximum at concentrations above 10-8 M. Moreover, treatment with ISO drastically reduced the response induced by PHN concentrations lower but not higher than 10-6 M, favoring a concentration-dependent response between 10-6 and 10- 4 M PHN, similar to that induced by equimolar NE concentrations. Thus, the NE-induced reduction in glycogen content of the rat pineal gland is mainly mediated by α-adrenoceptors and modulated by intracellular mechanisms by β- adrenoceptors.

AB - In the rat pineal gland the glycogen stores were cytochemically localized in astrocytes and pinealocytes. Moreover, it was found that norepinephrine (NE) induced a time- and concentration-dependent reduction in pineal glycogen content and yielded lactic acid. The NE effect was prevented by blocking α1- but not α2 or β-adrenoceptors. Activation of α2- adrenoceptors induced a small decrease in glycogen levels that could have pre- and postsynaptic components. Activation of β-adrenoceptors with 10- 12-10-3 M isoproterenol (ISO) induced a bell shape concentration- response curve, presumably due to desensitization, since the response induced by 10-4 M ISO was greater with shorter period of stimulation. On the other hand, activation of α1-adrenoceptors with 10-12-10-3 M phenylephrine (PHN) induced a hyperbolic concentration-response curve with a maximum at concentrations above 10-8 M. Moreover, treatment with ISO drastically reduced the response induced by PHN concentrations lower but not higher than 10-6 M, favoring a concentration-dependent response between 10-6 and 10- 4 M PHN, similar to that induced by equimolar NE concentrations. Thus, the NE-induced reduction in glycogen content of the rat pineal gland is mainly mediated by α-adrenoceptors and modulated by intracellular mechanisms by β- adrenoceptors.

KW - Adrenoceptor

KW - Desensitization

KW - Epiphysis cerebri

KW - Glycogen

KW - Lactic acid

KW - Norepinephrine

UR - http://www.scopus.com/inward/record.url?scp=17444446811&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=17444446811&partnerID=8YFLogxK

U2 - 10.1016/S0006-8993(97)00273-4

DO - 10.1016/S0006-8993(97)00273-4

M3 - Article

VL - 760

SP - 34

EP - 41

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1-2

ER -