Public Health
08.10.2013

Level of growth hormone in the brain is good indicator of longevity

The statement is research performed at USP in partnership with the University of Rochester, USA

Foto: Marcos Santos/USP Imagens
Results benefit understanding of evolution and aging of species
Results benefit understanding of evolution and aging of species

The IGF1R hormone, growth factor known as insulin-like and used to measure the levels of aging may be a good indicator of the longevity of rodents, but only when considering the brain tissues. This is one of the findings of a survey conducted at the Faculty of Veterinary Medicine and Animal Science (FMVZ) USP in partnership with the University of Rochester, USA. The study compared the dose of 16 IGF1R rodent species with different life spans and body weights as capybara, paca, mice, rats, ramsters, chinchillas and guinea pigs, among others.

According to Professor Augusto Coppi, Laboratory of Stochastic Stereology and Chemical Anatomy (LSSCA) Department of Surgery FMVZ, the scientific literature on the subject suggests that IGF1R levels in organs such as brain, heart, kidneys and lungs could indicate the longevity of rodents. In our studies, we noticed that the greater longevity of the animal, the lower levels of the hormone in the brain. However, this is not true when we analyzed the kidneys, the lungs and heart of these animals, says the researcher. According to estereologista, the results benefit the general understanding of the evolution and aging of the species and may be beneficial for interventional medicine geriatric. A paper on the research was published in April 2013 the journal Aging, which has 4,696 impact factor is one of the most respected in the field of aging. The text can be accessed at this link.

The peripheral shape is IGF1R growth hormone, or can be measured in organs like lungs, kidneys, heart and brain, whereas the growth hormone GH can be dosed only in the pituitary (gland in the brain). With the IGF1R have peripheral insulin action: it leaves the pancreas, enters the bloodstream and is taken up by the organs, explains.

The species with a life cycle have a greater reduction in the levels of IGF1R with aging, as observed in rodents lower body weight used in the laboratory as guinea pigs, rats and mice. Researchers FMVZ and the University of Rochester wanted to check whether this same pattern also applies to wild rodents and higher body weight. The research objective was to determine whether the responses of IGF1R were different according to the life cycle and the body weight as it will reach senility, says estereologista.

The study was conducted based on the count of IGF1R levels in the heart, lungs, kidneys and brains of 16 species of rodents in different age and body mass cycles, using molecular biology techniques (immunoblot), used to measure protein associated Stereology

Coppi explains the longevity of approximately 16 species varies greatly among themselves. For mice, is four years. For the wild rat (naked mole rat) is 31 years, for the capybara, 15 years; paca for 16 years. But the weight of the 16 species is also quite varied: about 20 grams for a mouse and an average of 55 pounds for capybaras.

Results

The main results show that levels of IGF1R showed a strong negative correlation with age only for the rodent brain and no correlation with body mass. These results suggest that the regulation occurs during aging IGF1R only to nervous tissue but not in peripheral tissues [lung, heart and kidneys] clarifies the researcher.

Another finding of this study the researchers FMVZ and the University of Rochester is the fact that some worms, mosquitoes and mutant mice have a lower index of IGF1R as they age. Our question was: does the animal live longer if you have less IGF1R? Our hypothesis was confirmed: animals with greater longevity have lower levels of the hormone, he says.

These results may perhaps be useful to assist in the creation of a drug acting at different periods of longevity in specific brain regions, avoiding side effects in peripheral tissues, ie without presenting the drug effects on other organs suggests Coppi. This drug could enhance memory and cognitive functions, acting in the limbic system and hippocampus, and this treatment would be true regardless of body weight, pointing hypothetically the teacher.

Source: USP