Stepping stones along the exercise stress response pathway
Two key factors cooperatively regulate the stress response to exercise


Date:
February 24, 2022
Source:
University of Tsukuba
Summary:
A research team confirmed that interference with the action
of arginine vasopressin and corticotrophin-releasing hormone
inhibits stress responses in rats during moderate-intensity
exercise. Their findings suggest that these factors cooperatively
regulate adrenocorticotropic hormone secretion.



FULL STORY ========================================================================== Athletes and the general population alike train to promote health
and physical fitness. With repeated exposure to the minimal stress of
exercise, the body adapts. Researchers at the University of Tsukuba have
sought to paint a detailed picture of the physiological stress response
to moderate-intensity exercise that occurs after the lactate threshold
is surpassed. In a recently published study in Neuroendocrinology,
the researchers have confirmed that arginine vasopressin and corticotrophin-releasing hormone regulate an important indicator of
stress: the adrenocorticotropic hormone.


==========================================================================
With sufficiently lengthy moderate-intensity exercise, anaerobic
respiration processes contribute to producing fuel for the brain and
muscles. Lactic acid can build up in the blood, at which point the stress response kicks in.

The researchers confirmed that, in response to exercise stress in rats, adrenocorticotropic hormone (ACTH) is secreted, which involves the release
of arginine vasopressin (AVP) and corticotrophin-releasing hormone (CRH)
from hypothalamic neurons into the pituitary portal vessels. They used an established animal exercise-stress model to represent human physiological responses and blockers for each factor. "This avoided the difficulties
of earlier studies that had used blood samples only, and were unable to identify the causal relationship between ACTH and AVP and CRH responses
during exercise stress," explains Professor Hideaki Soya. Because of
the study's design, the research team could evaluate each factor's
contribution separately and in combination, as well as factor-related activation in the brain, in response to the exercise protocol.

AVP blockers and CRH blockers had an effect on ACTH release from the
anterior pituitary only during running (not before running). Each blocker
had an effect alone, yet a larger effect was observed when blockers were administered in combination. Furthermore, both arginine vasopressin and corticotrophin- releasing hormone neurons were activated with exercise
stress; however, concentrations of adrenocorticotropic hormone in the
blood were only correlated with activation of arginine vasopressin
neurons. "Thus, both arginine vasopressin and corticotrophin-releasing
hormone may contribute to regulating adrenocorticotropic hormone
secretion, in different ways, but may do so cooperatively, and therefore together play an important role in the stress response," says first
author Kanako Takahashi.

By uncovering this piece of the puzzle, the precise point at which the
stress response is activated by exercise is one step closer to being
fully understood.

Because excessive stress has profound physiological effects, like delaying recovery from exercise, continued research may provide a clearer picture
of the stress response, which could contribute to improved athletic and
fitness training efficiency and outcomes.

========================================================================== Story Source: Materials provided by University_of_Tsukuba. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Kanako Takahashi, Takeru Shima, Mariko Soya, Jang Soo Yook, Hikaru
Koizumi, Subrina Jesmin, Tsuyoshi Saito, Masahiro Okamoto,
Hideaki Soya.

Exercise-Induced Adrenocorticotropic Hormone Response Is
Cooperatively Regulated by Hypothalamic Arginine Vasopressin and
Corticotrophin- Releasing Hormone. Neuroendocrinology, 2021; DOI:
10.1159/000521237 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220224112635.htm

--- up 11 weeks, 5 days, 7 hours, 13 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)