Table 6.

Epinephrine and norepinephrine at rest and incremental exercise during normoxia and hypoxia in men and women

	Normoxia			Hypoxia
	Rest	10%	20%	Rest	10%	20%
Young adults
Men (n = 16)
Arterial norepinephrine	133 ± 9	139 ± 10	159 ± 9†	147 ± 10	160 ± 10†	172 ± 10†
Venous norepinephrine	191 ± 10	181 ± 8	186 ± 8	226 ± 17*	210 ± 13*†	208 ± 11†
v-a norepinephrine difference	58 ± 10	42 ± 6†	28 ± 8†	79 ± 12*	50 ± 8†	36 ± 7†
Arterial epinephrine	41 ± 6	46 ± 5	52 ± 5†	66 ± 7*	86 ± 9*†	91 ± 8*†
Venous epinephrine	17 ± 3	34 ± 4†	42 ± 4†	22 ± 3	56 ± 5*	73 ± 7*†
Women (n = 15)
Arterial norepinephrine	120 ± 22	131 ± 25	137 ± 25†	139 ± 28	136 ± 23	144 ± 25†
Venous norepinephrine	180 ± 26	165 ± 25	172 ± 25	218 ± 24*	185 ± 22*†	179 ± 21†
v-a norepinephrine difference	59 ± 8	34 ± 6†	35 ± 6†	79 ± 9*	49 ± 6†	35 ± 7†
Arterial epinephrine	30 ± 2	28 ± 3‡	36 ± 4‡	48 ± 5*	56 ± 6*‡	72 ± 11*†
Venous epinephrine	14 ± 1	25 ± 3†‡	30 ± 3†‡	20 ± 3	48 ± 4*†	70 ± 8*†
Older adults
Men (n = 5)
Arterial norepinephrine	204 ± 7	219 ± 13	240 ± 14†	231 ± 10*	256 ± 20	264 ± 25
Venous norepinephrine	298 ± 27	275 ± 21	286 ± 19	351 ± 37*	330 ± 29*	318 ± 20*
v-a norepinephrine difference	93 ± 22	55 ± 10†	47 ± 8†	121 ± 27	74 ± 11	55 ± 7†
Arterial epinephrine	69 ± 6	68 ± 8	69 ± 11	93 ± 9*	106 ± 10*	148 ± 21*†
Venous epinephrine	41 ± 8	48 ± 7	66 ± 9†	49 ± 7	84 ± 15*	106 ± 18*†
Women (n = 6)
Arterial norepinephrine	234 ± 47	270 ± 54†	282 ± 44†	272 ± 43	308 ± 29	356 ± 47*†
Venous norepinephrine	410 ± 49	369 ± 61†	363 ± 50†	508 ± 74	431 ± 35	438 ± 49*
v-a norepinephrine difference	175 ± 14‡	99 ± 18†	82 ± 12†	237 ± 52‡	123 ± 15†	88 ± 19†
Arterial epinephrine	59 ± 11	66 ± 15	61 ± 13	99 ± 13*	125 ± 23*	184 ± 58*†
Venous epinephrine	49 ± 21	54 ± 15	75 ± 22†	70 ± 27	104 ± 27*†	134 ± 32*†

Values are means ± SE in pg/ml; n, no. of subjects.

^*P < 0.05 vs. normoxia.

^†P < 0.05 vs. rest.

^‡P < 0.05 vs. men.