Navigation Links
Longer-Lived Rodents Have Lower Levels of Thyroid Hormone

The thyroid may play an important role in longevity, with longer-lived rodents showing significantly lower levels of a thyroid hormone that speeds metabolism, a new study has found.//

The study further strengthens the theory that the faster an animal’s metabolism, the shorter its life, and vice versa, said Mario Pinto, the study’s lead author. The thyroid releases hormones that regulate metabolic rate.

“Thyroid hormones are key regulators of metabolism and have been widely implicated to influence longevity,” the authors wrote. Pinto will present the study “Differential thyroid hormone activity in rodents with different life spans” at a poster session Oct. 9 at Comparative Physiology 2006: Integrating Diversity. The study was carried out by Pinto and Rochelle Buffenstein, City College of New York.

Thyroid key to metabolic rate

The thyroid gland produces thyroxine (T4) which converts to triiodothyronine (T3) in the presence of iodine. T3 is the active component of T4 and is the key hormone in regulating metabolism, Pinto said. When an animal becomes cold, for example, its body converts T4 to T3 to speed metabolism and warm the body, he explained.

'Mice strains that exhibit extended longevity tend to have lower thyroid hormone concentrations than shorter living strains,' the authors wrote. 'Significant declines in thyroid hormone correlate well with enhanced maximum lifespan.'

The study compared the levels of these thyroid hormones among four groups of rodents with different life spans: mice, guinea pigs, Damara mole-rats and naked mole-rats. Mice live to about three and a half years; guinea pigs live to six years; Damara mole-rats to 15 years; and naked mole-rats to 28 years.

The animals were of different ages, but at comparable points in their life spans. For example, the mole-rats, which live 28 years, were two years old. The mice, which live about 3.5 years, were six months old. The s tudy determined the levels of T3 and T4 for each animal.

T4 levels vary the most

T4 levels varied significantly between all of the groups, with the shorter-lived groups having higher levels of T4 than longer-lived groups. The mice, for example, had twice as much T4 as the Damara mole-rats and had and three times more than that of the naked mole-rats, Pinto reported. There was also a significant difference in T3 levels between the naked mole-rats and the guinea pigs, but not between any of the other groups.

'These hormone concentration differences correlate with maximum species lifespan and suggest an important regulatory role of thyroid hormone in longevity,' the researchers concluded. However, because T3 levels did not differ significantly among all the groups, further research in this area using larger sample sizes (numbers of rodents in each group) is needed, Pinto said.


Related medicine news :

1. Rodents to be replaced with Dogs for cancer Research
2. Glucose Causes Death of Brain Cells in Rodents Following Hypoglycemic Coma
3. Simvastatin Plus Niacin May Lower Heart Risks
4. Ritalin May Lower Cocaine Abuse
5. Eating More Often May Help Lower Cholesterol
6. Lower surgical volume linked to higher death rate
7. Lowering blood pressure beneficial for PAD patients
8. Lower chance of bone fracture with Vitamin D supplementation
9. Tea Pill Lowers Cholesterol
10. Aspirin Lowers Leukemia Risk
11. Almonds Help Lower Cholesterol
Post Your Comments:

(Date:11/26/2015)... ... 2015 , ... PRMA Plastic Surgery is updating their record books yet again ... free flap breast reconstruction surgery! , “What an accomplishment for the PRMA team, says ... and it’s an honor to have served all of these women.” , PRMA is ...
(Date:11/26/2015)... ... November 26, 2015 , ... Indosoft Inc., developer and distributor of the ... to improve system efficiency and reliability. , The new Q-Suite 6 platform is based ... system avoids locking itself into a specific piece of software for many key components ...
(Date:11/25/2015)... ... November 25, 2015 , ... Finnleo, a leader in ... on several models of traditional and far-infrared saunas. , For traditional saunas, ... the most traditional Finnish sauna wood, and Finnleo uses only European Grade A Nordic ...
(Date:11/25/2015)... ... November 26, 2015 , ... Ministers, senior government ... ANDI Pan African Centres of Excellence, and public R&D institutions, civil societies and ... opening of the 5th African Network for Drugs and Diagnostics Innovation, ANDI, Stakeholders ...
(Date:11/25/2015)... FL (PRWEB) , ... November 25, 2015 , ... ... center, is encouraging people across the country to celebrate their sobriety and show ... people to post “before and after” photos this Thanksgiving with the hashtag #FacesOfGratitude ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... 2015 --> ... blends immunotherapy with Bremachlorin-photodynamic therapy for advanced cancer. ... immunotherapy with Bremachlorin-photodynamic therapy for advanced cancer.   ... immunotherapy with Bremachlorin-photodynamic therapy for advanced cancer.   ... that immunotherapy can be efficiently combined with photodynamic therapy ...
(Date:11/26/2015)... --> --> Juntendo University ... contrast weighting of MRI for patients with Multiple Sclerosis ... agreement with SyntheticMR in order to use SyMRI in clinical ... to generate multiple contrast images from a single scan and ... making it possible to both fine tune images and recreate ...
(Date:11/26/2015)... SAN FRANCISCO , November 26, 2015 ... 1.82 billion by 2022, according to a new report by ... as Chronic Kidney Disease (CKD) which demands kidney transplantation is ... convenient and cost effective substitute for organ transplantation. --> ... 1.82 billion by 2022, according to a new report by ...
Breaking Medicine Technology: