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Published on: April 28, 2016
Neuropeptide Y has a central inhibitory action on the hypothalamic-pituitary-thyroid axis
1Tupper Research Institute and Department of Medicine, Division of Endocrinology, Diabetes, Metabolism and Molecular Medicine, New England Medical Center, Boston, Massachusetts 02111, USA.
Endocrinology
|May 18, 2001
Summary
Neuropeptide Y (NPY) may inhibit the thyroid axis during fasting. Studies show NPY suppresses thyroid hormones and proTRH, mimicking fasting effects and suggesting a key role in central hypothyroidism.
Area of Science:
- Neuroendocrinology
- Metabolic Regulation
Background:
- Neuropeptide Y (NPY) is implicated in mediating leptin's central nervous system effects.
- NPY neurons in the arcuate nucleus innervate paraventricular nucleus (PVN) neurons producing thyrotropin-releasing hormone (TRH).
Purpose of the Study:
- To investigate the role of NPY in regulating the hypothalamic-pituitary-thyroid (HPT) axis during fasting.
- To determine if NPY administration mimics the HPT axis alterations observed during fasting.
Main Methods:
- Intracerebroventricular administration of NPY in animal models.
- Radioimmunoassay (RIA) to measure circulating thyroid hormones (T3, T4) and TSH.
- In situ hybridization histochemistry to quantify proTRH messenger RNA in the PVN.
Main Results:
- NPY administration significantly suppressed circulating T3 and T4 levels.
- TSH levels were inappropriately normal or low following NPY infusion.
- ProTRH messenger RNA levels in the PVN were significantly reduced.
- Observed changes mimicked the effects of fasting on the HPT axis, even in pair-fed controls.
Conclusions:
- NPY plays a significant role in the inhibition of the HPT axis during fasting.
- NPY administration induces a state of central hypothyroidism.
- These findings highlight NPY as a key mediator in the fasting-induced suppression of thyroid function.
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