Related Experiment Video
Updated: Jun 18, 2026
04:14
In vivo Characterization of Endocrine Disrupting Chemical Effects via Thyroid Hormone Action Indicator Mouse
Published on: October 6, 2023
Expression of preproNPY and precursor VIP mRNAs in rats under hypo- or hyperthyroid conditions
L Huffman1, M Michalkiewicz, K E Vrana
1Department of Physiology, West Virginia University Health Sciences Center, Morgantown, West Virginia 26506, USA.
Molecular and Cellular Neurosciences
|November 17, 2009
Summary
Thyroid activity is influenced by neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP). This study found that while thyroid conditions don't alter NPY/VIP mRNA in major nerves, hypothyroidism increases NPY mRNA within the thyroid gland.
Area of Science:
- Neuroendocrinology
- Thyroid physiology
- Molecular biology
Background:
- Neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) are neurotransmitters found in thyroid nerves, potentially modulating thyroid function.
- Understanding the regulation of these neuropeptides during altered thyroid states is crucial for comprehending thyroid-gland neural control.
Purpose of the Study:
- To investigate changes in NPY and VIP mRNA expression in thyroid-innervating ganglia and the thyroid gland itself under hypo- and hyperthyroid conditions.
- To determine if thyroid dysfunction affects the central or peripheral neural regulation of neuropeptide synthesis.
Main Methods:
- Induction of hypothyroidism (propylthiouracil) and hyperthyroidism (thyroxine) in rats.
- Analysis of preproNPY and precursor VIP mRNA levels using Northern blot in superior cervical ganglia, local thyroid ganglia, and thyroid tissue.
Main Results:
- No significant alterations in preproNPY or VIP mRNA were observed in the superior cervical ganglia or local thyroid ganglia in response to induced hypo- or hyperthyroidism.
- A notable increase in preproNPY mRNA levels was detected within the thyroid gland following propylthiouracil-induced hypothyroidism.
Conclusions:
- Altered thyroid states (hypo- and hyperthyroidism) do not significantly impact the expression of NPY and VIP precursor mRNAs in the major nerve ganglia supplying the thyroid.
- Hypothyroidism, induced by propylthiouracil, leads to an upregulation of intrathyroidal NPY mRNA, suggesting localized adaptive changes within the thyroid gland.
Related Concept Videos
01:27Hyperthyroidism II: Pathophysiology
Hyperthyroidism is a hypermetabolic state caused by elevated levels of thyroid hormones, triiodothyronine (T3) and thyroxine (T4). It results from dysregulation at the thyroid, pituitary, or immune system level and affects multiple organ systems.PathophysiologyThe most common cause of hyperthyroidism is Graves’ disease, an autoimmune disorder in which antibodies, specifically thyroid-stimulating antibodies (TSAb), a subtype of TSH receptor antibodies (TRAb), bind to and activate TSH receptors...
01:25Hyperthyroidism I: Introduction
Hyperthyroidism is a type of thyrotoxicosis characterized by the thyroid gland's overproduction of the thyroid hormones triiodothyronine (T3) and thyroxine (T4). This hormone excess increases the basal metabolic rate and enhances sensitivity to catecholamines.DiagnosisDiagnosis is based on clinical features and biochemical testing. It typically shows suppressed thyroid-stimulating hormone (TSH) levels below 0.4 mIU/L, with elevated free T3 and/or T4. Additional tests, including thyroid...
01:20Synthesis and Regulation of Thyroid Hormones
Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:23Hypothyroidism II: Pathophysiology
Hypothyroidism is a disorder characterized by insufficient production of thyroid hormones, which regulate metabolism, energy balance, and multiple organ systems.TypesHypothyroidism is classified based on the level of dysfunction. Primary hypothyroidism results from intrinsic thyroid gland dysfunction, causing reduced hormone production despite normal or increased stimulation. Secondary hypothyroidism arises from inadequate thyroid-stimulating hormone (TSH) secretion by the pituitary. Tertiary...
01:24Graves Disease II: Pathophysiology
Graves’ disease is an autoimmune disorder characterized by the production of thyroid-stimulating immunoglobulins (TSI) that activate TSH receptors, leading to excessive synthesis and release of thyroid hormones (T3 and T4) and resulting in hyperthyroidism.Among all causes of hyperthyroidism, Graves’ disease is the most common and can happen at any age, though it is more frequent in women. It produces a hypermetabolic state with features such as weight loss, tachycardia, tremor, and heat...
01:28Graves' Disease I: Introduction
Graves' disease is an autoimmune disorder that causes hyperthyroidism, or overactivity of the thyroid gland. It results from autoantibodies called thyroid-stimulating immunoglobulins (TSIs), which bind to thyroid-stimulating hormone (TSH) receptors, leading to overstimulation of hormone production and a hypermetabolic state.EtiologyAlthough considered idiopathic, Graves’ disease has well-established contributing factors. There is a strong genetic component, with increased prevalence in...