Elevated shear rate-induced by exercise increases eNOS ser¹¹⁷⁷ but not PECAM-1 Tyr⁷¹³ phosphorylation in human conduit artery endothelial cells

Figures & data

Table 1. Summary of participants’ characteristics.

	Exercise (n = 6)	Control (n = 5)	P value
Age (years)	27± 7	25 ± 5	0.466
BMI (m/kg^2)	26.0 ± 1.5	22.2 ± 0.8	0.001
VO2peak (ml/kg/min)	51.2 ± 10.8	53.3 ± 13.0	0.800
MVC (kg)	43.2 ± 4.4	38.1 ± 4.1	0.429

BMI: body mass index; VO_2peak: peak oxygen consumption; MVC: maximal voluntary contraction.

Figure 1. Mean shear rate in the exercise (n = 6) and control groups (n = 5) prior to intervention (Baseline) and at 10, 20 and 30 min. Results are presented as mean ± SD, P < 0.05. *Significantly different from Baseline, ^†Significantly different from 10 min, ^#Significantly different from control group.

Table 2. Radial artery haemodynamics in the exercise (n = 6) and control groups (n = 5), prior to intervention (Baseline) and at 10, 20 and 30 min.

		Baseline	10 min	20 min	30 min	Group	Time	Interaction
Diameter (mm)	Exercise	2.77 ± 0.20	2.99 ± 0.27	2.93 ± 0.12	3.02 ± 0.17	P = 0.015	P = 0.046	P = 0.205
	Control	2.33 ± 0.35	2.39 ± 0.45	2.45 ± 0.43	2.37 ± 0.37
Blood velocity (cm/min)	Exercise	4.84 ± 4.01	13.74 ± 7.48*	16.97 ± 6.92^*†	17.88 ± 8.45^*†	P = 0.016	P < 0.0001	P < 0.0001
	Control	3.05 ± 1.27	2.41 ± 1.03	2.81 ± 1.46	2.99 ± 1.60
Blood flow (ml/min)	Exercise	16.56 ± 12.69	54.73 ± 27.28*	68.17 ± 26.64^*†	72.25 ± 32.73^*†	P = 0.009	P < 0.0001	P < 0.0001
	Control	8.47 ± 4.63	7.02 ± 3.51	8.54 ± 4.51	8.83 ± 5.24
Anterograde flow (ml/min)	Exercise	18.23 ± 12.01	66.15 ± 26.20*	82.32 ± 21.85^*†	84.50 ± 29.99^*†	P = 0.044	P < 0.0001	P < 0.0001
	Control	11.34 ± 6.25	10.94 ± 5.05	12.85 ± 6.12	12.57 ± 7.23
Retrograde flow (ml/min)	Exercise	-1.72 ± 2.30	−11.42 ± 4.86	−14.15 ± 10.65	−10.24 ± 6.70	P = 0.051	P = 0.022	P = 0.096
	Control	−2.31 ± 2.07	−3.67 ± 2.10	−4.44 ± 1.97	−4.40 ± 2.32
Anterograde shear rate (1/s)	Exercise	79.32 ± 58.53	232.55 ± 117.69*	283.51 ± 84.54^*†	277.70 ± 121.14^*†	P = 0.011	P < 0.0001	P < 0.0001
	Control	68.39 ± 23.11	61.23 ± 21.76	67.29 ± 41.16	68.71 ± 31.40
Retrograde shear rate (1/s)	Exercise	−6.93 ± 8.56	−42.05 ± 31.63	−50.11 ± 37.19	−35.99 ± 22.53	P = 0.315	P = 0.035	P = 0.095
	Control	−17.23 ± 9.55	−21.55 ± 7.11	−21.95 ± 13.79	−20.50 ± 7.96
Heart rate (beats per min)	Exercise	65 ± 15	65 ± 13	67 ± 14	66 ± 12	P = 0.612	P = 0.646	P = 0.877
	Control	59 ± 17	61 ± 11	63 ± 8	63 ± 10
Mean arterial pressure (mmHg)	Exercise	101 ± 8	105 ± 11	109 ± 8*	108 ± 14*	P = 0.006	P = 0.147	P < 0.0001
	Control	91 ± 6	86 ± 6	88 ± 6	87 ± 7*

Notes: Results are presented as mean ± SD, P < 0.05.

*Significantly different from Baseline, ^†Significantly different from 10 min

Figure 2. eNOS, eNOS Ser¹¹⁷⁷ phosphorylation (peNOS), PECAM-1 and PECAM-1 Tyr⁷¹³ phosphorylation (pPECAM-1) in the exercise and control groups pre- and post-intervention. A, Representative confocal microscopy images of radial artery endothelial cells (EC)s stained for eNOS (a, b) and peNOS Ser¹¹⁷⁷ (c, d) pre (a, c) and post (b, d) handgrip exercise, images are taken from the same participant from the exercise group. B, Representative confocal microscopy images of radial artery EC stained for PECAM-1 (a, b) and pPECAM-1 Tyr⁷¹³ (c, d) pre (a, c) and post (b, d) handgrip exercise, images are taken from the same participant from the exercise group. Mean fluorescence intensity of eNOS; C, peNOS Ser¹¹⁷⁷; D, PECAM-1; E, and pPECAM-1 Tyr⁷¹³; F is summarised. The mean fluorescence intensity pre intervention was assigned a value of 1, and the relative intensity post intervention was calculated. Results are mean ± SD, *Significantly different from Pre (P < 0.05).