A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats

The ontogenesis of adenohypophyseal dopamine receptors, assessed by haloperidol-displaceable [3H]didydroergocryptine (DHE) binding of 1-, 12-, 20-, 28-day-old female rats was studied in correlation with the prolactin releasing effect of haloperidol (1 mg/kg), a dopaminergic antagonist. A specific do...

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Publicado: 1984
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01653806_v12_n2_p167_BecudeVillalobos
http://hdl.handle.net/20.500.12110/paper_01653806_v12_n2_p167_BecudeVillalobos
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spelling paper:paper_01653806_v12_n2_p167_BecudeVillalobos2023-06-08T15:14:52Z A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats adenohypophysis dihydroergocryptine binding dopamine receptors haloperidol ontogenesis prolactin sex differences dopamine receptor haloperidol prolactin radioisotope adenohypophysis age animal cell dihydroergocryptine h 3 drug receptor binding endocrine system nonhuman ontogeny pharmacokinetics rat sex difference The ontogenesis of adenohypophyseal dopamine receptors, assessed by haloperidol-displaceable [3H]didydroergocryptine (DHE) binding of 1-, 12-, 20-, 28-day-old female rats was studied in correlation with the prolactin releasing effect of haloperidol (1 mg/kg), a dopaminergic antagonist. A specific dopaminergic receptor could be quantified at the time of birth (Bmax = 2.5 ± 0.5 fmol/mg; Kd = 1.5 ± 0.2 μM), anterior pituitary receptor density (fmol bound/mg) increased non-significantly henceforth and a slight ontogenic increase of Kd values was also observed. Haloperidol failed to increase prolactin in newborn female rats; at 4 days, a significant increase was evidenced, and from then onwards the response rose markedly with age. As sex differences in the dopaminergic modulation of prolactin release have been documented, the hyperprolactinemic effect of haloperidol in correlation with [3H]DHE binding in anterior pituitary of 28-day-old female and male rats was studied. Though the prolactinemic increment achieved by haloperidol was significantly higher in female than in male rats, [3H]DHE binding was not statistically different between sexes. These data indicate: (a) a specific binding site for [3H]DHE in anterior pituitary of female rats is present from the first postnatal days. From then onwards, a gradual but slight increment in both, Bmax and Kd for the dopaminergic agonist is observed until puberty; (b) at 28 days, no clear difference in Bmax and Kd is present in [3H]DHE binding between male and female rats; (c) by contrast, haloperidol shows a prolactin releasing effect that increases markedly with age in the female. At 28 postnatal days, serum prolactin levels attained after haloperidol in the female were significantly higher than those achieved in the male. Thus, differences of magnitude in the coupled response may sometimes not be accounted for by differences in number, or affinity, of receptor sites. © 1984. 1984 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01653806_v12_n2_p167_BecudeVillalobos http://hdl.handle.net/20.500.12110/paper_01653806_v12_n2_p167_BecudeVillalobos
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic adenohypophysis
dihydroergocryptine binding
dopamine receptors
haloperidol
ontogenesis
prolactin
sex differences
dopamine receptor
haloperidol
prolactin
radioisotope
adenohypophysis
age
animal cell
dihydroergocryptine h 3
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
rat
sex difference
spellingShingle adenohypophysis
dihydroergocryptine binding
dopamine receptors
haloperidol
ontogenesis
prolactin
sex differences
dopamine receptor
haloperidol
prolactin
radioisotope
adenohypophysis
age
animal cell
dihydroergocryptine h 3
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
rat
sex difference
A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
topic_facet adenohypophysis
dihydroergocryptine binding
dopamine receptors
haloperidol
ontogenesis
prolactin
sex differences
dopamine receptor
haloperidol
prolactin
radioisotope
adenohypophysis
age
animal cell
dihydroergocryptine h 3
drug receptor binding
endocrine system
nonhuman
ontogeny
pharmacokinetics
rat
sex difference
description The ontogenesis of adenohypophyseal dopamine receptors, assessed by haloperidol-displaceable [3H]didydroergocryptine (DHE) binding of 1-, 12-, 20-, 28-day-old female rats was studied in correlation with the prolactin releasing effect of haloperidol (1 mg/kg), a dopaminergic antagonist. A specific dopaminergic receptor could be quantified at the time of birth (Bmax = 2.5 ± 0.5 fmol/mg; Kd = 1.5 ± 0.2 μM), anterior pituitary receptor density (fmol bound/mg) increased non-significantly henceforth and a slight ontogenic increase of Kd values was also observed. Haloperidol failed to increase prolactin in newborn female rats; at 4 days, a significant increase was evidenced, and from then onwards the response rose markedly with age. As sex differences in the dopaminergic modulation of prolactin release have been documented, the hyperprolactinemic effect of haloperidol in correlation with [3H]DHE binding in anterior pituitary of 28-day-old female and male rats was studied. Though the prolactinemic increment achieved by haloperidol was significantly higher in female than in male rats, [3H]DHE binding was not statistically different between sexes. These data indicate: (a) a specific binding site for [3H]DHE in anterior pituitary of female rats is present from the first postnatal days. From then onwards, a gradual but slight increment in both, Bmax and Kd for the dopaminergic agonist is observed until puberty; (b) at 28 days, no clear difference in Bmax and Kd is present in [3H]DHE binding between male and female rats; (c) by contrast, haloperidol shows a prolactin releasing effect that increases markedly with age in the female. At 28 postnatal days, serum prolactin levels attained after haloperidol in the female were significantly higher than those achieved in the male. Thus, differences of magnitude in the coupled response may sometimes not be accounted for by differences in number, or affinity, of receptor sites. © 1984.
title A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
title_short A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
title_full A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
title_fullStr A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
title_full_unstemmed A developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
title_sort developmental study of adenohypophyseal dopaminergic receptors and of haloperidol-induced prolactin release in rats
publishDate 1984
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01653806_v12_n2_p167_BecudeVillalobos
http://hdl.handle.net/20.500.12110/paper_01653806_v12_n2_p167_BecudeVillalobos
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