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Dopaminergic inhibition of prolactin release from pituitary glands of the domestic fowl incubated in vitro.
J Endocrinol. 1984 Oct; 103(1):63-9.JE

Abstract

Anterior pituitary glands from broiler fowl were incubated by themselves, with hypothalamic tissue or with thyrotrophin releasing hormone (TRH) in medium containing dopamine and its antagonist pimozide. The presence of hypothalamic tissue or TRH resulted in a stimulation of release of prolactin. Neither dopamine nor pimozide affected prolactin release directly from the pituitary gland. Dopamine inhibited the release of prolactin stimulated by hypothalamic tissue or TRH, in a concentration-dependent fashion. Pimozide diminished the response to dopamine. After pituitary glands were preincubated for 20 h in medium containing oestradiol-17 beta, the basal release of prolactin was enhanced as was the response to TRH. Both basal and TRH-stimulated release of prolactin from the oestrogen-primed pituitary glands was inhibited by dopamine, an effect blocked by pimozide. Hypothalami from broiler fowl were incubated for up to 8 h in medium containing dopaminergic drugs and pituitary glands were incubated in this medium, alone or with pimozide. As indicated by the prolactin released by the pituitary glands, the hypothalami appeared to secrete prolactin-releasing activity in a time-related fashion. Dopaminergic activity was also present in the hypothalami, since pimozide enhanced the prolactin-releasing activity of the medium. Dopamine apparently inhibited and pimozide stimulated the secretion of releasing activity from the hypothalamus. These results suggest that dopamine inhibits release of prolactin directly from the pituitary gland only when prolactin secretion is high. The hypothalamus secretes at least two factors regulating prolactin secretion, a prolactin-releasing factor and a dopaminergic prolactin-inhibiting factor. Dopamine may also play an inhibitory role in the regulation of secretion of the prolactin-releasing factor.

Authors

No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

6434684

Citation

Hall, T R., and A Chadwick. "Dopaminergic Inhibition of Prolactin Release From Pituitary Glands of the Domestic Fowl Incubated in Vitro." The Journal of Endocrinology, vol. 103, no. 1, 1984, pp. 63-9.
Hall TR, Chadwick A. Dopaminergic inhibition of prolactin release from pituitary glands of the domestic fowl incubated in vitro. J Endocrinol. 1984;103(1):63-9.
Hall, T. R., & Chadwick, A. (1984). Dopaminergic inhibition of prolactin release from pituitary glands of the domestic fowl incubated in vitro. The Journal of Endocrinology, 103(1), 63-9.
Hall TR, Chadwick A. Dopaminergic Inhibition of Prolactin Release From Pituitary Glands of the Domestic Fowl Incubated in Vitro. J Endocrinol. 1984;103(1):63-9. PubMed PMID: 6434684.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Dopaminergic inhibition of prolactin release from pituitary glands of the domestic fowl incubated in vitro. AU - Hall,T R, AU - Chadwick,A, PY - 1984/10/1/pubmed PY - 1984/10/1/medline PY - 1984/10/1/entrez SP - 63 EP - 9 JF - The Journal of endocrinology JO - J Endocrinol VL - 103 IS - 1 N2 - Anterior pituitary glands from broiler fowl were incubated by themselves, with hypothalamic tissue or with thyrotrophin releasing hormone (TRH) in medium containing dopamine and its antagonist pimozide. The presence of hypothalamic tissue or TRH resulted in a stimulation of release of prolactin. Neither dopamine nor pimozide affected prolactin release directly from the pituitary gland. Dopamine inhibited the release of prolactin stimulated by hypothalamic tissue or TRH, in a concentration-dependent fashion. Pimozide diminished the response to dopamine. After pituitary glands were preincubated for 20 h in medium containing oestradiol-17 beta, the basal release of prolactin was enhanced as was the response to TRH. Both basal and TRH-stimulated release of prolactin from the oestrogen-primed pituitary glands was inhibited by dopamine, an effect blocked by pimozide. Hypothalami from broiler fowl were incubated for up to 8 h in medium containing dopaminergic drugs and pituitary glands were incubated in this medium, alone or with pimozide. As indicated by the prolactin released by the pituitary glands, the hypothalami appeared to secrete prolactin-releasing activity in a time-related fashion. Dopaminergic activity was also present in the hypothalami, since pimozide enhanced the prolactin-releasing activity of the medium. Dopamine apparently inhibited and pimozide stimulated the secretion of releasing activity from the hypothalamus. These results suggest that dopamine inhibits release of prolactin directly from the pituitary gland only when prolactin secretion is high. The hypothalamus secretes at least two factors regulating prolactin secretion, a prolactin-releasing factor and a dopaminergic prolactin-inhibiting factor. Dopamine may also play an inhibitory role in the regulation of secretion of the prolactin-releasing factor. SN - 0022-0795 UR - https://www.unboundmedicine.com/medline/citation/6434684/Dopaminergic_inhibition_of_prolactin_release_from_pituitary_glands_of_the_domestic_fowl_incubated_in_vitro_ L2 - https://joe.bioscientifica.com/doi/10.1677/joe.0.1030063 DB - PRIME DP - Unbound Medicine ER -