Preferential increase in pituitary prolactin versus vasoactive intestinal peptide as a function of estradiol benzoate dose in the ovariectomized rat.

Title

Preferential increase in pituitary prolactin versus vasoactive intestinal peptide as a function of estradiol benzoate dose in the ovariectomized rat.

Creator

Carrillo A J; Doherty P C; Guan X B; Sturtevant J R; Walro D G

Publisher

Endocrinology

Date

1991
1991-01

Description

Vasoactive intestinal peptide (VIP) is synthesized in various tissues, including the anterior pituitary gland, where it may stimulate the release of PRL. Because estrogen plays a central role in the regulation of PRL, it becomes important to determine the effects of this steroid on both pituitary VIP and PRL. To study this, pituitary VIP and PRL and plasma PRL were assayed in ovariectomized rats after treatment with estradiol benzoate (EB; 0.007, 0.07, 0.7, 7 or 70 microgram/rat). Pituitary and plasma TSH were also determined as well as VIP content in the medial basal hypothalamus, suprachiasmatic region, cerebral cortex, and jejunum. Oil-treated rats served as controls. Injection of 0.7 or 7 microgram EB resulted in a significant increase in pituitary PRL without changing plasma PRL levels or pituitary VIP content compared to values in the control group. Only treatment with 70 microgram EB produced a significant increase in both pituitary VIP and PRL as well as in plasma PRL compared to control values. EB treatment at any of the doses used had no significant effect on pituitary and plasma TSH or VIP content in any of the other tissues examined. These data show that pituitary PRL and VIP are differentially regulated in response to estrogen. The increases in pituitary VIP and basal plasma PRL after treatment with the highest dose of EB suggest that pituitary VIP may be involved in the development of estrogen-induced hyperprolactinemia. These data also show that the regulations of pituitary VIP and TSH are independent of each other in the estrogen-treated rat.

Subject

Animals; Brain/drug effects/*metabolism; Dose-Response Relationship; Drug; Estradiol/*pharmacology; Female; Inbred Strains; Organ Specificity; Ovariectomy; Pituitary Gland/drug effects/*metabolism; Prolactin/blood/*metabolism; Rats; Thyrotropin/blood/metabolism; Vasoactive Intestinal Peptide/*metabolism

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

131–138

Issue

1

Volume

128

Citation

Carrillo A J; Doherty P C; Guan X B; Sturtevant J R; Walro D G, “Preferential increase in pituitary prolactin versus vasoactive intestinal peptide as a function of estradiol benzoate dose in the ovariectomized rat.,” NEOMED Bibliography Database, accessed April 18, 2021, https://neomed.omeka.net/items/show/4900.

Social Bookmarking