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Quantification of catecholamine neurotransmitters released from cutaneous vasoconstrictor nerve endings in men with cervical spinal cord injury.

Authors :
Tomonori Nakata
Manabu Shibasaki
Yukihide Nishimura
Tokio Kinoshita
Takamasa Hashizaki
Yoshi-ichiro Kamijo
Ken Kouda
Yasunori Umemoto
Fumihiro Tajima
Source :
American Journal of Physiology: Regulatory, Integrative & Comparative Physiology; Mar2023, Vol. 324 Issue 3, pR345-R352, 8p
Publication Year :
2023

Abstract

Control of cutaneous circulation is critically important to maintain thermoregulation, especially in individuals with cervical spinal cord injury (CSCI) who have no or less central thermoregulatory drive. However, the peripheral vasoconstrictor mechanism and capability have not been fully investigated after CSCI. Post- and presynaptic sensitivities of the cutaneous vasoconstrictor system were investigated in 8 CSCI and 7 sedentary able-bodied (AB) men using an intradermal microdialysis technique. Eight doses of norepinephrine (NE, 10<superscript>-8</superscript> to 10<superscript>-1</superscript> M) and five doses of tyramine (TY, 10<superscript>-8</superscript>, 10<superscript>-5</superscript> to 10<superscript>-2</superscript> M) were administered into the anterior right and left thigh, respectively. Endogenous catecholamines, noradrenaline, and dopamine, collected at the TY site, were determined by high-performance liquid chromatography with electrochemical detection. Regardless of vasoconstrictor agents, cutaneous vascular conductance decreased dose-dependently and responsiveness was similar between the groups (NE: Group P = 0.255, Dose P = 0.014; TY: Group P = 0.468, Dose P < 0.001), whereas the highest dose of each drug induced cutaneous vasodilation. Administration of TY promoted the release of noradrenaline and dopamine in both groups. Notably, the amount of noradrenaline released was similar between the groups (P = 0.819), although the concentration of dopamine was significantly greater in individuals with CSCI than in AB individuals (P = 0.004). These results suggest that both vasoconstrictor responsiveness and neural functions are maintained after CSCI, and dopamine in the skin is likely to induce cutaneous vasodilation. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03636119
Volume :
324
Issue :
3
Database :
Complementary Index
Journal :
American Journal of Physiology: Regulatory, Integrative & Comparative Physiology
Publication Type :
Academic Journal
Accession number :
161956065
Full Text :
https://doi.org/10.1152/ajpregu.00063.2022