Prolactin secretion is highly regulable, and the possibility exists that there are local intrapituitary factors controlling prolactin secretion. Recently, the neuropeptides vasoactive intestinal peptide ( @entity12180 ), @entity16424 and substance @entity10133 ) have been co-localized to the lactotroph in the female @entity35 . We investigated the effects of alterations in prolactin status in vivo on pituitary and hypothalamic expression of these peptides by specific radioimmunoassays and mRNA analysis. In the anterior pituitary, following @entity1767 treatment, the contents of both @entity12180 and @entity16424 were suppressed to below detectable levels. Similarly, after @entity2847 treatment, the content of @entity12180 was decreased to below the detection limit of the assay while @entity16424 (14.2 +/- 1.3 vs control 21.0 +/- 2.1 fmol/mg, P less than 0.05) also showed a significant reduction. The levels of @entity12180 mRNA and @entity16424 mRNA in these groups showed the same qualitative change as their respective peptides. Concurrent treatment with high-dose @entity2931 modified the @entity12180 peptide response to @entity2847 (1368.7 +/- 149.2 vs @entity2847 843.4 +/- 82.7 fmol/mg, P less than 0.05) but not to @entity1767 . @entity2931 -induced decreases in @entity16424 content were not influenced by either treatment. The pituitary content of SP showed a fall after @entity2931 treatment (1.1 +/- 0.01 vs control 6.4 +/- 0.8 fmol/mg, P less than 0.05) which was not significantly altered by either @entity2847 or @entity1767 . Likewise, SP mRNA levels in the pituitary were decreased by 90% following @entity2931 treatment. Hypothalamic expression of these peptides did not change with any of the treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

XXXX anterior pituitary neuropeptides following chronic prolactin manipulation: a combined radioimmunoassay and mRNA study.

@entity2847 :: ('MESH:D001971', 'Chemical') :: ['bromocriptine'] @entity10133 :: ('2155', 'Species') :: ['P (SP'] @entity2931 :: ('CHEBI:50114', 'Chemical') :: ['oestrogen', 'Oestrogen'] @entity16424 :: ('MESH:D019004', 'Chemical') :: ['galanin'] @entity1767 :: ('MESH:D006220', 'Chemical') :: ['haloperidol'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity12180 :: ('117064(Tax:10116)', 'Gene') :: ['VIP']
@entity35 :: (10116,Species) :: ['Rat']
