Sex differences in middle cerebral artery reactivity and hemodynamics independent from changes in systemic arterial stiffness in Sprague–Dawley rats

Figures

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  FIGURE 1. Transcranial Doppler ultrasound and pulsatility index (PI) of left middle cerebral artery (MCA) and left internal carotid artery in adult Sprague–Dawley (SD) rats. Color Doppler ultrasound was used to identify the LMCA which appeared as the first large branch arising from the intracranial internal carotid artery (Panel a). Waveforms obtained from pulse wave Doppler analysis provide maximum, minimum, and mean flow velocities which are used to calculate PI (Panel b). Left MCA (Panel c) and ICA (Panel d) PI in 25‐week‐old male versus female SD rats. Data are mean ± SD; n = 7–10.

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  FIGURE 2. Representative images of immunohistochemical staining and the analysis of COX‐2 (Panel a), eNOS (Panel b), PG synthase (Panel c) and TxA2‐R (Panel d) in the endothelial and vascular smooth muscle cell layer of the left MCA in adult male versus female SD rats. Data are mean ± SD; n = 3–7.

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  FIGURE 3. Cerebral blood flow velocities of left MCA and ICA in adult Sprague–Dawley (SD) rats. Left MCA (Panel a) and ICA (Panel b) Vmax, Vmin, and Vmean in adult male versus female SD rats. Data are mean ± SD, n = 7–10.

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  FIGURE 4. Aortic arch (Panel a) and left common carotid artery (Panel b) pulse wave velocity (PWV) in adult male versus female SD rats. Data are mean ± SD, n = 8–12.

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  FIGURE 5. Vasodilatory response to acetylcholine in LMCAs obtained from male and female SD rats. LMCAs from male and female SD were pre‐constricted with U‐46619 (10−7 M). Data are mean ± SD, n = 5 per group.

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  FIGURE 6. Contraction response of LMCAs to U‐46619 in male and female SD rats. LMCAs from male (n = 10) and female (n = 13) were exposed to U‐46619 as indicated. Parallel experiments in intact arteries (a) and arteries preincubated with indomethacin (b; 10−5 M) are shown. Data are mean ± SD.