Impact of peripheral skin cooling on neuroendocrine leukocytic and hematological reactions during Hypergravity

Michael Nordine; Niklas Kagelmann; Jan Kloka; Hanns-Christian Gunga; Viktor Heinz; Niklas Pilz; Oliver Opatz; Tomas L Bothe

doi:10.1038/s41526-025-00486-9

Impact of peripheral skin cooling on neuroendocrine leukocytic and hematological reactions during Hypergravity

NPJ Microgravity. 2025 Jul 2;11(1):30. doi: 10.1038/s41526-025-00486-9.

Authors

Michael Nordine¹, Niklas Kagelmann², Jan Kloka³, Hanns-Christian Gunga², Viktor Heinz², Niklas Pilz², Oliver Opatz^#², Tomas L Bothe^#²

Affiliations

¹ Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, Goethe University Frankfurt, University Hospital Frankfurt, Theodor-Stern Kai 7, 60590, Frankfurt, Germany. nordine@med.uni-frankfurt.de.
² Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Charité -Universitätsmedizin Berlin, Berlin, Germany.
³ Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, Goethe University Frankfurt, University Hospital Frankfurt, Theodor-Stern Kai 7, 60590, Frankfurt, Germany.

^# Contributed equally.

Abstract

Optimal neuroendocrine responses are essential during hypergravity (+Gz) exposure. Peripheral skin cooling (PSC) may enhance neuroendocrine function, potentially improving +Gz resiliency and influencing leukocyte and hematologic factors. This study investigated whether PSC augments the cumulative +Gz stress index (CGSI) and shifts it toward noradrenergic dependency. Eighteen men underwent a graded +Gz profile in a crossover design, with PSC applied using Arctic Sun cooling pads. Neuroendocrine and blood profiles were assessed pre- and post-+Gz. CGSI did not differ between groups, but serum osmolality increased only in PSC (p = 0.03). In PSC, CGSI correlated with norepinephrine (p < 0.01, r = 0.71) and other markers, suggesting enhanced norepinephrine responsiveness despite similar serum levels. This response may be cardio-protective for space missions and ICU patients. Additionally, baseline serum metanephrine emerged as a potential marker for +Gz resilience, with PSC showing potential leukocytic and hematologic involvement in CGSI.