Normal
Mouse
Average mean pressure =
111 mmHg
Heart rate = 580 beats per minute
Obese
Mouse
Average mean pressure =
109 mmHg
Heart rate = 560 beats per minute
Leptin is a hormone secreted from fat that regulates body weight. As fat stores increase, leptin secreted to the blood increases. Leptin causes an increase in metabolic rate and diminshed hunger. Naturally occuring mice that are missing leptin, called ob/ob, have a very low metabolic rate and are always hungry. If food is readily available, these animals become obese.
We had hypothesized that the high blood pressure observed in human obesity was caused by excessive amounts of leptin. Our hypothesis would predict that animals that are missing leptin should have very low blood pressure. This, however, turned out not to be the case. See our recent report for details.
Steven J.
Swoap. Altered leptin signaling is sufficient, but not required, for the
hypotension associated with caloric restriction. Amer. J. Physiology:
281(6): H2473-H2479, 2001. http://ajpheart.physiology.org/cgi/content/abstract/281/6/H2473