Rasgos conductuales y presión arterial en ratas espontáneamente hipertensas [SHR]. = Behavioral traits and blood pressure in spontaneously hypertensive rats [SHR].

RESUMEN

Las ratas espontáneamente hipertensas (SHR) son hiperactivas y presentan bajos niveles de ansiedad, siendo la hiperactividad disociable de la hipertensión. Para estudiar la relación entre otros rasgos conductuales de las SHR y la presión arterial (PA), 35 machos SHR y 36 ratas macho Wistar-Kyoto (WKY) de 10-11 semanas de vida fueron evaluadas en el Laberinto en Cruz Elevado (LCE) y en el Campo Abierto (CA; 3 sesiones), luego de lo cual se midió la PA. La PA de las SHR fue superior a la de las WKY (p<.0001). En ambas pruebas, las SHR exhibieron una mayor actividad motora (AM) horizontal (LCE: p<.0001; CA: p<.0001 las 3 sesiones) y vertical (LCE: p<.0001; CA: p<.0001 las 3 sesiones) y fueron menos ansiosas (LCE: p=.0025; CA: p<.0001 las 3 sesiones). En ninguna prueba la AM horizontal y la ansiedad de las SHR y WKY correlacionaron con la PA. Por el contrario, la AM vertical (rearing) de las SHR correlacionó con la PA en las sesiones 1 y 2 del CA (r=.401, p=.017; r=.346, p=.042). Los resultados indican que la AM horizontal y los niveles de ansiedad en las SHR son rasgos disociables de la PA mientras que la AM vertical parecería no serlo.

ABSTRACT

Spontaneously hypertensive rats (SHR) are hyperactive and display low levels of anxiety, their hyperactivity being dissociable from their hypertension. To study the relationship between other behavioral traits of SHR and blood pressure (BP), 35 ten-eleven weeks old male SHR and 36 male Wistar-Kyoto (WKY) rats of the same age were tested in the Elevated Plus Maze (EPM) and in the Open Field (OF; 3 sessions) tests, after which BP was measured. SHR showed significantly higher BP than WKY (p<.0001). In both behavioral tests, SHR displayed higher horizontal locomotor activity (EPM: p<.0001; OF: p<.0001 in the 3 sessions), higher vertical locomotor activity (EPM: p<.0001; OF: p<.0001 in the 3 sessions) and were less anxious (EPM: p=.0025; OF: p<.0001 in the 3 sessions). The horizontal locomotor activity and anxiety levels of SHR and WKY did not correlate with BP either in the EPM or the OF. Positive correlations were found between vertical locomotor activity (rearing) and BP in sessions 1 and 2 of the OF (r=.401, p=.017; r=.346, p=.042). The results showed that in SHR
the low level of anxiety is, as in the case of hyperactivity, a behavioral trait dissociable from hypertension while vertical locomotor activity would not seem to be.