[The measurement of baroreflex sensitivity in stress-induced hypertensive rats by spectral analysis].
Simultaneous spectral analysis of short-term systolic blood pressure variability (SBPV) and heart rate variability (HRV) was applied to determine the change of baroreflex sensitivity (BRS) in Sprague-Dawley (SD) rats. The modulus of the transfer function between fluctuations in systolic pressure and beat-to-beat interval would be an appropriate quantification of BRS. The animal experiment was performed on two groups of rats: normotensive rats and stress-induced hypertensive rats (SIHR). V1-receptor antagonist d(CH2)5Tye(Me) AVP of arginine vasopressin (AVP) was microinjected into intracerebroventricle. The results showed that, in base-line condition before administration, although the BRS in very low frequency band (0-0.035 Cycle/Beat, VLF), low frequency band (0.035-0.12 Cycle/Beat, LF), high frequency band (0.12-0.32 Cycle/Beat, HF) and total BRS(the sum of the three bands) were all decreased, the BRS in VLF(P < 0.05) and LF(P < 0.01) decreased significantly by statistics; and that, to the SIHR, the BRS in VLF was significantly lower after AVP-V1 administration than in base-line condition, while to normotensive rats, the BRS did not change. It indicates that the facilitating effect of AVP on the beroreflex in SIHR is mainly due to V1-receptor in central nerve system. In summary, the transfer function between SBPV and beat-to-beat interval fluctuation could be an index of BRS. This method can be developed for future clinical application.
Wu
G
G
Department of Biomedical Engineering, Shanghai Medical University, Shanghai 200032.
Hu
G
G
Shen
L
L
Tang
D
D
Lu
L
L
Li
P
P
D000818:Animals; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure; D006339:Heart Rate; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013312:Stress, Physiological / Q000150:complications*