Title: Differential response of neuropeptide Y, substance P and vasoactive intestinal polypeptide in the rat anterior pituitary gland to alterations in thyroid hormone status
Abstract: We have compared the effects of thyroidectomy with those of thyroxine (T4) replacement and excess T4 treatment on neuropeptide Y (NPY) in the rat anterior pituitary, and compared these with the effects on substance P (SP) and vasoactive intestinal peptide (VIP). Thyroidectomy produced large increases in the peptide content of NPY (335 +/- 58 fmol/gland vs 15 +/- 4 fmol/gland in controls), SP (581 +/- 90 vs 199 +/- 32 fmol/gland) and VIP (1386 +/- 395 vs 417 +/- 77 fmol/gland) together with large increases in the respective prohormone encoding mRNAs, NPY 21,760% +/- 1290%, preprotachykinin-A (PPT-A; which encodes the substance P precursor) 1744% +/- 190% and VIP 680% +/- 129%. Thyroidectomy together with T4 replacement produced an increase in both NPY peptide (426 +/- 72 vs 15 +/- 4 fmol/gland) and mRNA content (970% +/- 156% of controls). The peptide contents of SP and VIP were not significantly different from controls. PPT-A and VIP mRNA levels were decreased relative to controls (31% +/- 8% and 23% +/- 10% respectively). In intact animals treated with excess T4 (hyperthyroid animals), SP and VIP peptide contents were significantly reduced (55 +/- 13 vs 199 +/- 32 fmol/gland and 226 +/- 24 vs 417 +/- 77 fmol/gland respectively) and the SP and VIP encoding mRNAs were also decreased (8% +/- 3% and 11% +/- 4% respectively). In this group there was no detectable alteration in either the peptide or mRNA content of NPY.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication Year: 1994
Publication Date: 1994-11-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 16
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