Rat Monty Pythons fare?

[Guest guest]

Hi All,

There is an article in the new issue of Nature Med that

piqued interest regarding the use of " sumo " .

Previously, it has been somewhat humorously

noted that:

" Sumo wrestlers, football players, and basketball players play an

important role in our world, their small numbers do not pose a threat

to our survival. However, their body habitus should not be the goal

for the average male of the future. "

This was previously subject of our grist mill, and is from:

http://tinyurl.com/4me67 ,

which is

Samaras TT, Elrick H.

Less is better.

J Natl Med Assoc. 2002 Feb;94(2):88-99.

PMID: 11853051 [PubMed - indexed for MEDLINE]

Another background paper Medline abstract that

has not been shared among us is, from the actively

exercising overweight group suggests that the above

paper is correct:

Nippon Eiseigaku Zasshi. 1995 Aug;50(3):730-6.

Risk factors for mortality and mortality rate of sumo wrestlers

Hoshi A, Inaba Y.

We compared the mortality rate of sumo wrestlers with that of the

contemporaneous Japanese male population, and inferred the usefulness

of an

index for predicting longevity in sumo wrestlers. The standardized

mortality

ratios (SMR) for sumo wrestlers were very high in each period, and

also high for

ages from 35 to 74. 's proportional hazards model analysis

revealed that the

variables in " nyuumaku " entry year and BMI were statistically

significant (p <

0.05) factors in mortality. In the survival curves, the lower BMI

group had good

life expectancy compared with the higher BMI group. In conclusion,

the higher

rate of mortality in sumo wrestlers seems to be due to the markedly

higher rate

of mortality from 35 to 74 years old. In sumo wrestlers, also, this

study

provides evidence that the higher overweight groups have

substantially higher

risks for mortality.

PMID: 7474495 [PubMed - indexed for MEDLINE]

And, here is the preview of prospective studies for

using a new rat model of human obesity. It was of

interest, I believe, that the rats die early, but

" their infertility is fully reversible with simple

measures such as diet restriction " .

Need we search further to generate interest in aging research

investment, as well as humor.

'Sumo' rats set researchers on hunt for obesity genes

Nature Medicine Feb 2005 11, 108

K. S. Jayaraman

" We are ready to start the project right away and hopefully

clone the gene in two years. " - Friedman, Rockefeller

University

The world's fattest rats are the focus of a new joint project for

scientists from India and the US. The researchers hope to identify

and clone the genes responsible for the 'sumo' rats that weigh in at

about 1.4 kilograms (3.1 pounds), about four times the standard

weight for a rat.

" If, as we believe, this is a new obesity gene, it could have

major implications, " says Nappan Veettil Giridharan, deputy director

of India's National Institute of Nutrition (NIN) in Hyderabad. The

NIN maintains a colony of about 400 sumo rats in their twenty-first

generation. Giridharan says all evidence indicates that the genes may

differ from all obese rat models currently available.

Like other rodent models, the sumo rats serve as good paradigms

for human disorders such as diabetes and infertility. But unlike the

other models, these rats also develop cataracts and tumors, and their

infertility is fully reversible with simple measures such as diet

restriction. The rats also have kinky tails, not seen in any other

obese models.

From day 35 on, the rats rapidly gain weight and their body shape

gradually becomes rotund. Too fat to move, they lie supine with their

heads close to the food pellets. They also show signs of rapid aging

and die in about 18 months, compared with the normal three years,

Giridharan says.

To map the mutation, Giridharan and his colleagues plan to cross

the Indian rat with unrelated strains such as the Brown Norway and

Fischer-344 strains. Genetic analysis on the resulting progeny will

then help localize the mutation and ultimately clone it. DNA analysis

will be carried out by the US collaborators, led by Friedman,

at Rockefeller University in New York.

In 1994, Friedman and his colleagues cloned the obese gene and, in

1995, identified its product, leptin. Friedman showed that overweight

mice with defective ob genes—and who cannot make leptin—respond to

injections of leptin by losing up to 30% of their body weight in two

weeks.

The $500,000 cost of the project is to be shared by the US

National Institutes of Health and the Indian Council of Medical

Research (ICMR).

" We are ready to start the project right away and hopefully clone

the gene in two years, " says Friedman. The ICMR is planning another

large study to use the NIN rat to screen for potential obesity and

diabetes drugs.

Cheers, Al Pater.