Naturally occurring hypertension in New World nonhuman primates: potential role of the perifornical hypothalamus

Abstract

Smith OA, Astley CA. Naturally occurring hypertension in New World nonhuman primates: potential role of the perifornical hypothalamus. Am J Physiol Regul Integr Comp Physiol 292: R937-R945, 2007. First published October 5, 2006; doi:10.1152/ajpregu.00400.2006.-Hypertension is a prominent underlying factor in the genesis of cardiovascular-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. We used chronically implanted pressure transducers to assess normally occurring blood pressure and heart rate levels at rest and during routine laboratory procedures in a group of one of these New World primates (Aotus sp.). Resting mean arterial pressure ranged from 72 to 130 mmHg. Three animals were judged to have resting mean arterial pressure levels in the hypertensive range (Ն110 mmHg). In all of the animals, pressor responses to routine laboratory events were exaggerated (average highest mean pressure during 1 min from any session was 97-196 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 cardiovascular responses that contribute to the development of essential hypertension. essential hypertension; environment; perifornical/lateral hypothalamus TWO SPECIES of New World monkeys, the "woolly" (Lagothrix lagotricha) and the "owl" (Aotus sp.) monkey, are potentially valuable models of naturally occurring hypertension. These species came to our attention because of the elevated rates of cardiovascular (CV)-related mortality of these monkeys in captivity and the subsequent pathological findings. The woolly monkeys show hyaline arteriolar nephrosclerosis, one of the earliest histological changes associated with hypertension in humans (7), and the Aotus shows cardiomegaly and cardiomyopathy (8, 27), which are also associated with hypertension in humans. The causes of the mortality in these animals include stroke, renal failure, aortic aneurysm rupture, and congestive heart failure, all of which are strongly suggestive of hypertensive disease.To follow up on these observations, we performed preliminary surveys on both species by direct measurement of blood pressure via arterial puncture. The animals were under ketamine sedation, and the pressures in most animals exceeded the accepted "normal" blood pressure levels for primates. Many of the levels were excessively high. The results of the study of the woolly monkeys in zoos and in private hands have been reported elsewhere (7). The survey of the owl monkeys took place at the Battelle Pacific Nort...

Evaluation of blood pressure in feline night monkeys (Aotus azarae infulatus) under different restraint protocols

“… in Cebus apella . In the physical restraint group, the blood pressure values were higher compared to the resting pressure . This probably happened because of the stress caused by restraint, which causes the release of catecholamine, thereby increasing the values of BP.…”

“…HR was considered high in all protocols tested compared to data obtained by Smith and Astley in Aotus nancymai in resting condition. However, the values found confirm what was described in other studies for anesthetized Aotus azarae infulatus .…”

The normal and abnormal owl monkey (Aotus sp.) heart: looking at cardiomyopathy changes with echocardiography and electrocardiography

“…Cardiomyopathy has a decreased prevalence in owl monkeys that have not been in captivity for an extended period of time [13]. A previous study indicated that owl monkeys react to laboratory disturbances with significant, prolonged elevations in blood pressure [21] The study of cardiomyopathy in owl monkeys is not only important in maintaining a self-sustaining breeding colony, but it may be a useful model for human cardiomyopathy.…”

Influência de diferentes protocolos de contenção nosvalores do eletrocardiograma de macacos-da-noite (Aotus azarae infulatus)

“…Os valores da frequência cardíaca (FC) observados neste trabalho estão de acordo com os encontrados por Baer (1994), Rajendra et al (2010) e Galante (2013) em Aotus submetidos à anestesia, no entanto foram considerados elevados em comparação aos dados obtidos por Smith & Astley (2007) em Aotus nancymai em condição de repouso. Sabe-se que, tanto os anestésicos utilizados quanto fatores estressantes como a contenção física elevam a FC de forma considerável (Smith & Astley 2007).…”

“…Sabe-se que, tanto os anestésicos utilizados quanto fatores estressantes como a contenção física elevam a FC de forma considerável (Smith & Astley 2007).…”