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摘要
This study examines (a) the temporal stability of hemodynamic indices of systolic and diastolic function in C57BL/6 mice under 1.5% isoflurane (ISO) (v/v) anesthesia conditions in 50:50 O-2/N2O (v/v) within 90 min post-induction, and (b) the effects of Mn2+ on the mouse hemodynamic response in male C57BL/6 mice (n = 16). Left ventricular catheterizations allowed estimation of the hemodynamic indices. Hypertonic saline infusion (10%) allowed absolute volume quantification in conjunction with a separate series of aortic flow experiments (n = 3). In a separate cohort of mice (n = 6), MnCl2 (190 nmoles/g/bw) was infused via the left jugular for 29-39 min, following 11 min of baseline recording, to assess temporal responses. Stable temporal hemodynamic responses were achieved in control mice under ISO anesthesia. Hemodynamic indices during control, time-matched-control, baseline-Mn, and Mn-infused periods, were within normal expected ranges. No chronotropic changes were observed. Significant differences in systolic and diastolic cardiac indices of HR, EF, ESP, dP/dt(max), dP/dt(min), PAMP, tau(glantz), and tau(weiss)) resulted between baseline-Mn and Mn-infused time periods in Mn-treated mice at the 1% significance (p < 0.001). Transient positive, or negative, or positive followed by negative evoked pressure-volume loop shifts were observed (exemplified through changes in the endsystolic pressure-volume relationship and dP/dt(max)) in Mninfusion studies. It is concluded that Mn2+ can be used safely for prolonged mouse imaging studies, however, the significant variations elicited in cardiovascular hemodynamics post-manganese infusion, necessitate further investigations for its suitability and appropriateness for quantification of global cardiac function in image-based phenotyping.
- 出版日期2011-11
