Related Experiment Video
Updated: Jul 24, 2026
11:28
Analytical Techniques for Assaying Nitric Oxide Bioactivity
Published on: June 18, 2012
Thyroid status and nitric oxide in rat arterial vessels
R M McAllister1, I Albarracin, E M Price
1Department of Anatomy and Physiology and Kinesiology, Kansas State University, Manhattan, Kansas 66506, USA. mcallist@vet.ksu.edu
The Journal of Endocrinology
|April 9, 2005
Summary
Thyroid disease impacts cardiovascular health by altering vascular nitric oxide (NO) production and response. Both NO formation and the body's ability to respond to NO are significantly affected by hypo- and hyperthyroidism.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Vascular Biology
Background:
- Thyroid disease profoundly influences cardiovascular function.
- Hypothyroidism and hyperthyroidism are linked to altered vasodilation, suggesting a role for vascular nitric oxide (NO).
Purpose of the Study:
- To investigate the hypothesis that vascular NO formation capacity is decreased in hypothyroidism and increased in hyperthyroidism.
- To examine how thyroid status affects the capacity for NO production and the vascular response to NO.
Main Methods:
- Rats were induced into hypothyroid (using propylthiouracil) or hyperthyroid (using triiodothyronine) states for 3-4 months.
- Nitric oxide synthase (NOS) activity was measured in aortic extracts.
- Vascular responsiveness to NO was assessed by measuring cyclic guanosine monophosphate (cGMP) concentrations.
Main Results:
- Hypothyroid rats showed blunted growth and reduced soleus muscle citrate synthase activity.
- Hyperthyroid rats exhibited left ventricular hypertrophy and increased soleus muscle citrate synthase activity.
- Thyroid status significantly modulated NOS activity and cGMP formation, with hyperthyroidism increasing NOS activity and hypothyroidism increasing cGMP response.
Conclusions:
- Thyroid status significantly alters the capacity for both the formation of and the response to nitric oxide (NO).
- These alterations in NO pathways may explain the observed vascular dysfunction in thyroid disease states.
More Related Videos
Related Concept Videos
01:28Nitric Oxide Signaling Pathway
Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...
01:23Antihypertensive Drugs: Vasodilators
Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...