Increased Plasma Norepinephrine Response to Yohimbine in Elderly Men

Abstract

Background. The effects of aging on sympathetic nervous system and adrenomedullary outflow were estimated by the measurement of plasma norepinephrine (NE) and epinephrine (EPI) responses to yohimbine and clonidine in healthy young and healthy older subjects.

Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

“…Yohim bine is a member of the yohimb ane family, a large group of indole alkaloids derived from botanical sources. Pharmacologically, yohimbine is well-characterized as an alpha-2-adrenergic receptor antagonist and has been demonstrated to increase lipolysis in vitro [ 3 ], possibly due to its ability to stimulate a reliable increase in blood norepinephrine (NE); a finding evident in multiple studies involving human subjects receiving single dosages [ 4 - 7 ]. While not as universal a finding, other work has also demonstrated a significant increase in blood epinephrine (EPI) levels with yohimbine intake [ 7 , 8 ].…”

“…Pharmacologically, yohimbine is well-characterized as an alpha-2-adrenergic receptor antagonist and has been demonstrated to increase lipolysis in vitro [ 3 ], possibly due to its ability to stimulate a reliable increase in blood norepinephrine (NE); a finding evident in multiple studies involving human subjects receiving single dosages [ 4 - 7 ]. While not as universal a finding, other work has also demonstrated a significant increase in blood epinephrine (EPI) levels with yohimbine intake [ 7 , 8 ]. The increase in NE with acute yohimbine ingestion has been associated with an increase in blood free fatty acid levels [ 4 , 5 , 8 ], indicating a lipolytic effect of this nutrient.…”

Interactions between the cardiovascular and pain regulatory systems: an updated review of mechanisms and possible alterations in chronic pain

“…Of greatest relevance to this review are cardiovascular indices that reflect SNS arousal, including BP and heart rate [159][160][161]. Chronic pain patients with myofascial pain, orofacial pain, and arthritic pain all display greater resting heart rates than do pain-free healthy controls [3,162].…”

Presynaptic α-2C Adrenoceptor-mediated Control of Noradrenaline Release in Humans: Genotype- or Age-Dependent?

“…Finally, clonidine-induced maximal decrease in BPsyst was larger in elder WT a-2C AR than in young WT a-2C (and a-2CDel) AR subjects. The mechanism underlying this agedependent difference in BPsyst response to clonidine, which has been also observed by others, 35,36 is not completely understood at present. Possibly, age-dependent differences not only in pre-but also in postsynaptic a-2 AR might be involved.…”

“…Data, however, are controversial with some studies finding no age‐related changes in platelet α ‐2 AR density, other studies finding age‐related decreases in α ‐2 AR density and at least one study finding an age‐related increase in α ‐2 AR density 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 . A few studies have tested a possible age dependency of the effects of clonidine on pNA levels, but failed to show any age‐related differences in decreases in pNA following oral application of clonidine (usually 1.5–5 μ g/kg) 34 , 35 , 36 . We do not know the reason for the discrepancy between these and this study (age‐related decline in pNA response), but it might be owing to differences in the route of clonidine application: we applied clonidine i.v., whereas in the other studies, clondine was applied orally.…”