Related Experiment Video
Updated: Jul 6, 2026

Experimental Approach to Examine Leptin Signaling in the Carotid Bodies and its Effects on Control of Breathing
Published on: October 25, 2019
Role of locus coeruleus heme oxygenase-carbon monoxide-cGMP pathway during hypothermic response to restraint
Maria Ida Bonini Ravanelli1, Luiz G S Branco
1Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Abstract:
Central heme oxigenase-carbon monoxide (HO-CO) pathway has been shown to play a pyretic role in the thermoregulatory response to restraint. However, the specific site in the central nervous system where CO may act modulating this response remains unclear. LC is rich not only in sGC but also in heme oxygenase (HO; the enzyme that catalyses the metabolism of heme to CO, along with biliverdin and free iron). Therefore, the possible role of the HO-CO-cGMP pathway in the restraint-induced-hypothermia by LC neurons was investigated. Body temperature dropped about 0.7 degrees C during restraint. ZnDPBG (a HO inhibitor; 5 nmol, intra-LC) prevented the hypothermic response during restraint. Conversely, induction of the HO pathway in the LC with heme-lysinate (7.6 nmol, intra-LC) intensified the hypothermic response to restraint, and this effect was prevented by pretreatment with ODQ (a sGC inhibitor; given intracerebroventricularly, 1.3 nmol). Taken together, these data suggest that CO in the LC produced by the HO pathway and acting via cGMP is implicated in thermal responses to restraint.
Related Concept Videos
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Other Factors Affecting Respiration Centers
However, the ability to hold one's breath voluntarily is not limitless. When the CO2 concentration in the blood reaches a critical level,...
Physiology of Respiration II: Neurogenic Control of Respiration
Central Control
The brainstem is the primary site of central control, hosting respiratory centers:
Oxygen Transport in the Blood

