Role of the sympathetic nervous system in cerebrovascular responses to air-jet stress in rats

Figures & data

Figure 1.  Effects of air-jet stress on BP, CBFs, and vascular conductances in rats with unilateral cervical ganglionectomy. Rats were either untreated (control, n = 8) or were receiving an infusion of a β₂-adrenoceptor blocker (ICI 118551, n = 5). SE lines have been omitted for legibility. Vertical dashed lines show the onset of the stress trial. The inset graphs show a zoom in of the initial response of CBFs and vascular conductances. Note the much stronger increase in flow and conductance on the denervated side.

Table I.  Immediate cerebrovascular responses to air-jet stress in rats with unilateral cervical ganglionectomy.

		Δmax (%)		P
		Intact side	Denervated side
Carotid blood flows
	Control	49.5 ± 8.1	129 ± 11	0.0117
	ICI 118551	31.4 ± 3.7	118 ± 6	0.0431
Carotid vascular conductances
	Control	18.6 ± 4.3	78.4 ± 7.3	0.0117
	ICI 118551	NM	64.3 ± 4.3	–

Δ_max, peak increase; NM, non-measurable. Rats were either untreated (control, n = 8) or were receiving an infusion of a β₂-adrenoceptor blocker (ICI 118551, n = 5). P values refer to comparisons between intact and denervated sides carried out with the Wilcoxon signed-rank test. All comparisons between control and ICI 118551 groups were not significant by the Mann–Whitney test. Values are means ± SEM.

Figure 2.  Overall responses of BP, CBFs, and vascular conductances to air-jet stress in conscious rats with unilateral cervical ganglionectomy. Rats were either untreated (control, n = 8) or were receiving an infusion of a β₂-adrenoceptor blocker (ICI 118551, n = 5). For each variable, stress-induced changes were estimated as the sum of areas under and over the curves that were calculated from the stress onset up to the termination of the jet of air (5 min). Values are means ± SEM. *P < 0.05 versus respective control (Mann–Whitney test).