Submitted on June 8, 2006
Accepted on October 2, 2006
Naturally occurring hypertension in New World non-human primates: potential role of the perifornical hypothalamus
Orville A. Smith1* and Cliff A. Astley2
1 National Primate Research Center, Physiology and Biophysics, University of Washington, Seattle, Washington, United States
2 National Primate Research Center, University of Washington, Seattle, Washington, United States
* To whom correspondence should be addressed. E-mail: oas{at}u.washington.edu.
Hypertension is a prominent underlying factor in the genesis of cardiovascular (CV) related morbidity and mortality. A major impediment to the investigation into the causes of the disease is the paucity of naturally occurring animal models of the disease. There is evidence that some species of New World primates spontaneously become hypertensive. The mean arterial blood pressure (MAP) levels of a group of one of these (Aotus sp.) was investigated using chronically implanted pressure transducers to assess normally occurring blood pressure and heart rate levels at rest and during routine laboratory procedures. Resting MAP ranged from 72 to 130 mmHg. Three individuals were judged to have resting MAP levels in the hypertensive range (
110 mm Hg). Exaggerated pressor responses occurred in all animals in response to routine laboratory events (average highest mean pressure during one-minute from any session ranged from 97 to 196 mmHg).
Subsequently, the region of the perifornical/lateral hypothalamus known to produce elevated blood pressure and heart rate responses to electrical stimulation was removed and the blood pressure responses to the laboratory routines were significantly decreased and in some cases, eliminated. Control lesions in nearby tissue had no effect on these responses. This region may play a critical role in initiating or exacerbating CV responses that contribute to the development of essential hypertension.
