Absence of D1 dopamine receptors that stimulate prolactin release in the rat pituitary

D. Cocchi, S. Ingrassia, L. Rusconi, I. Villa, E. E. Müller

Research output: Contribution to journalArticle

Abstract

It has been shown recently that SKF 38393-A (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine-7-ol), a D-1 receptor agonist, possesses a prolactin-releasing effect in the rat, though the pituitary or central nervous system location of the receptors involved has not been clarified. The aim of our study was to elucidate this point. SKF 38393-A administered to freely moving adult female and male rats induced a striking, short-lived increase of basal prolactin levels. The prolactin stimulatory effect of SKF 38393-A was counteracted by pretreatment with SCH 23390, a D-1 receptor blocker. SKF 38393-A (10-10-10-6 M) added to monolayer primary cultures of anterior pituitary cells from rats of both sexes failed to modify prolactin release. At higher concentrations (10-5-10-4 M) the drug induced a slight inhibition of prolactin release. Similarly, SKF 38393-A failed to stimulate adenylate cyclase activity in anterior pituitary membranes from rats of both sexes at low concentrations, while it inhibited enzyme activity at higher concentrations (10-5-10-3 M). The latter effect was counteracted by concomitant addition of the antagonist of D-2 receptors, l-sulpiride. These data demonstrate that: (1) the anterior pituitary does not contain D-1-dopamine receptors (positively coupled to adenylate cyclase) stimulatory to prolactin release; (2) the striking prolactin-releasing effect of SKF 38393-A in the rat is due to activation of extra-pituitary D-1 dopamine receptors; (3) SKF 38393-A, at high concentrations, is capable of activating pituitary D-2 receptors.

Original languageEnglish
Pages (from-to)425-429
Number of pages5
JournalEuropean Journal of Pharmacology
Volume142
Issue number3
DOIs
Publication statusPublished - Oct 27 1987

Fingerprint

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine
Dopamine D1 Receptors
Prolactin
Dopamine Receptors
Adenylyl Cyclases
Sulpiride
Central Nervous System
Membranes

Keywords

  • Dopamine receptors
  • Primary pituitary cultures
  • Prolactin

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Pharmacology

Cite this

Absence of D1 dopamine receptors that stimulate prolactin release in the rat pituitary. / Cocchi, D.; Ingrassia, S.; Rusconi, L.; Villa, I.; Müller, E. E.

In: European Journal of Pharmacology, Vol. 142, No. 3, 27.10.1987, p. 425-429.

Research output: Contribution to journalArticle

Cocchi, D. ; Ingrassia, S. ; Rusconi, L. ; Villa, I. ; Müller, E. E. / Absence of D1 dopamine receptors that stimulate prolactin release in the rat pituitary. In: European Journal of Pharmacology. 1987 ; Vol. 142, No. 3. pp. 425-429.
@article{ac1af2b1e05041bd87a7c07c2d15e329,
title = "Absence of D1 dopamine receptors that stimulate prolactin release in the rat pituitary",
abstract = "It has been shown recently that SKF 38393-A (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine-7-ol), a D-1 receptor agonist, possesses a prolactin-releasing effect in the rat, though the pituitary or central nervous system location of the receptors involved has not been clarified. The aim of our study was to elucidate this point. SKF 38393-A administered to freely moving adult female and male rats induced a striking, short-lived increase of basal prolactin levels. The prolactin stimulatory effect of SKF 38393-A was counteracted by pretreatment with SCH 23390, a D-1 receptor blocker. SKF 38393-A (10-10-10-6 M) added to monolayer primary cultures of anterior pituitary cells from rats of both sexes failed to modify prolactin release. At higher concentrations (10-5-10-4 M) the drug induced a slight inhibition of prolactin release. Similarly, SKF 38393-A failed to stimulate adenylate cyclase activity in anterior pituitary membranes from rats of both sexes at low concentrations, while it inhibited enzyme activity at higher concentrations (10-5-10-3 M). The latter effect was counteracted by concomitant addition of the antagonist of D-2 receptors, l-sulpiride. These data demonstrate that: (1) the anterior pituitary does not contain D-1-dopamine receptors (positively coupled to adenylate cyclase) stimulatory to prolactin release; (2) the striking prolactin-releasing effect of SKF 38393-A in the rat is due to activation of extra-pituitary D-1 dopamine receptors; (3) SKF 38393-A, at high concentrations, is capable of activating pituitary D-2 receptors.",
keywords = "Dopamine receptors, Primary pituitary cultures, Prolactin",
author = "D. Cocchi and S. Ingrassia and L. Rusconi and I. Villa and M{\"u}ller, {E. E.}",
year = "1987",
month = "10",
day = "27",
doi = "10.1016/0014-2999(87)90082-3",
language = "English",
volume = "142",
pages = "425--429",
journal = "European Journal of Pharmacology",
issn = "0014-2999",
publisher = "Elsevier",
number = "3",

}

TY - JOUR

T1 - Absence of D1 dopamine receptors that stimulate prolactin release in the rat pituitary

AU - Cocchi, D.

AU - Ingrassia, S.

AU - Rusconi, L.

AU - Villa, I.

AU - Müller, E. E.

PY - 1987/10/27

Y1 - 1987/10/27

N2 - It has been shown recently that SKF 38393-A (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine-7-ol), a D-1 receptor agonist, possesses a prolactin-releasing effect in the rat, though the pituitary or central nervous system location of the receptors involved has not been clarified. The aim of our study was to elucidate this point. SKF 38393-A administered to freely moving adult female and male rats induced a striking, short-lived increase of basal prolactin levels. The prolactin stimulatory effect of SKF 38393-A was counteracted by pretreatment with SCH 23390, a D-1 receptor blocker. SKF 38393-A (10-10-10-6 M) added to monolayer primary cultures of anterior pituitary cells from rats of both sexes failed to modify prolactin release. At higher concentrations (10-5-10-4 M) the drug induced a slight inhibition of prolactin release. Similarly, SKF 38393-A failed to stimulate adenylate cyclase activity in anterior pituitary membranes from rats of both sexes at low concentrations, while it inhibited enzyme activity at higher concentrations (10-5-10-3 M). The latter effect was counteracted by concomitant addition of the antagonist of D-2 receptors, l-sulpiride. These data demonstrate that: (1) the anterior pituitary does not contain D-1-dopamine receptors (positively coupled to adenylate cyclase) stimulatory to prolactin release; (2) the striking prolactin-releasing effect of SKF 38393-A in the rat is due to activation of extra-pituitary D-1 dopamine receptors; (3) SKF 38393-A, at high concentrations, is capable of activating pituitary D-2 receptors.

AB - It has been shown recently that SKF 38393-A (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine-7-ol), a D-1 receptor agonist, possesses a prolactin-releasing effect in the rat, though the pituitary or central nervous system location of the receptors involved has not been clarified. The aim of our study was to elucidate this point. SKF 38393-A administered to freely moving adult female and male rats induced a striking, short-lived increase of basal prolactin levels. The prolactin stimulatory effect of SKF 38393-A was counteracted by pretreatment with SCH 23390, a D-1 receptor blocker. SKF 38393-A (10-10-10-6 M) added to monolayer primary cultures of anterior pituitary cells from rats of both sexes failed to modify prolactin release. At higher concentrations (10-5-10-4 M) the drug induced a slight inhibition of prolactin release. Similarly, SKF 38393-A failed to stimulate adenylate cyclase activity in anterior pituitary membranes from rats of both sexes at low concentrations, while it inhibited enzyme activity at higher concentrations (10-5-10-3 M). The latter effect was counteracted by concomitant addition of the antagonist of D-2 receptors, l-sulpiride. These data demonstrate that: (1) the anterior pituitary does not contain D-1-dopamine receptors (positively coupled to adenylate cyclase) stimulatory to prolactin release; (2) the striking prolactin-releasing effect of SKF 38393-A in the rat is due to activation of extra-pituitary D-1 dopamine receptors; (3) SKF 38393-A, at high concentrations, is capable of activating pituitary D-2 receptors.

KW - Dopamine receptors

KW - Primary pituitary cultures

KW - Prolactin

UR - http://www.scopus.com/inward/record.url?scp=0023522577&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023522577&partnerID=8YFLogxK

U2 - 10.1016/0014-2999(87)90082-3

DO - 10.1016/0014-2999(87)90082-3

M3 - Article

C2 - 2962879

AN - SCOPUS:0023522577

VL - 142

SP - 425

EP - 429

JO - European Journal of Pharmacology

JF - European Journal of Pharmacology

SN - 0014-2999

IS - 3

ER -