1
|
Liu T, Mukosera GT, Blood AB. The role of gasotransmitters in neonatal physiology. Nitric Oxide 2019; 95:29-44. [PMID: 31870965 DOI: 10.1016/j.niox.2019.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 11/07/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022]
Abstract
The gasotransmitters, nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO), are endogenously-produced volatile molecules that perform signaling functions throughout the body. In biological tissues, these small, lipid-permeable molecules exist in free gaseous form for only seconds or less, and thus they are ideal for paracrine signaling that can be controlled rapidly by changes in their rates of production or consumption. In addition, tissue concentrations of the gasotransmitters are influenced by fluctuations in the level of O2 and reactive oxygen species (ROS). The normal transition from fetus to newborn involves a several-fold increase in tissue O2 tensions and ROS, and requires rapid morphological and functional adaptations to the extrauterine environment. This review summarizes the role of gasotransmitters as it pertains to newborn physiology. Particular focus is given to the vasculature, ventilatory, and gastrointestinal systems, each of which uniquely illustrate the function of gasotransmitters in the birth transition and newborn periods. Moreover, given the relative lack of studies on the role that gasotransmitters play in the newborn, particularly that of H2S and CO, important gaps in knowledge are highlighted throughout the review.
Collapse
Affiliation(s)
- Taiming Liu
- Department of Pediatrics, Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - George T Mukosera
- Department of Pediatrics, Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA
| | - Arlin B Blood
- Department of Pediatrics, Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA; Lawrence D. Longo Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, 92354, USA.
| |
Collapse
|
2
|
Diong C, Jones PP, Tsuchimochi H, Gray EA, Hughes G, Inagaki T, Bussey CT, Fujii Y, Umetani K, Shirai M, Schwenke DO. Sympathetic hyper-excitation in obesity and pulmonary hypertension: physiological relevance to the 'obesity paradox'. Int J Obes (Lond) 2016; 40:938-46. [PMID: 27001546 DOI: 10.1038/ijo.2016.33] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/10/2016] [Accepted: 01/28/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Within the lung, sympathetic nerve activity (SNA) has an important role in facilitating pulmonary vasodilation. As SNA is elevated in obesity, we aimed to assess the impact of sympathetic hyper-excitation on pulmonary vascular homeostasis in obesity, and its potential role in ameliorating the severity of pulmonary hypertension (PH); the well-documented 'obesity paradox' phenomenon. METHODS Zucker obese and lean rats were exposed to normoxia or chronic hypoxia (CH-10% O2) for 2 weeks. Subsequently, pulmonary SNA (pSNA) was recorded (electrophysiology), or the pulmonary microcirculation was visualized using Synchrotron microangiography. Acute hypoxic pulmonary vasoconstriction (HPV) was assessed before and after blockade of β1-adrenergic receptors (ARs) (atenolol, 3 mg kg(-1)) and β1+β2-adrenergic (propranolol, 2 mg kg(-1)). RESULTS pSNA of normoxic obese rats was higher than lean counterparts (2.4 and 0.5 μV s, respectively). SNA was enhanced following the development of PH in lean rats, but more so in obese rats (1.7 and 6.8 μV s, respectively). The magnitude of HPV was similar for all groups (for example, ~20% constriction of the 200-300 μm vessels). Although β-blockade did not modify HPV in lean rats, it significantly augmented the HPV in normoxic obese rats (β1 and β2 blockade), and more so in obese rats with PH (β2-blockade alone). Western blots showed, while the expression of pulmonary β1-ARs was similar for all rats, the expression of β2-ARs was downregulated in obesity and PH. CONCLUSIONS This study suggests that sympathetic hyper-excitation in obesity may have an important role in constraining the severity of PH and, thus, contribute in part to the 'obesity paradox' in PH.
Collapse
Affiliation(s)
- C Diong
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - P P Jones
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - H Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - E A Gray
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - G Hughes
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - T Inagaki
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - C T Bussey
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| | - Y Fujii
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - K Umetani
- Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - M Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - D O Schwenke
- Department of Physiology-HeartOtago, University of Otago, Dunedin, New Zealand
| |
Collapse
|
3
|
Bai Z, Voituron N, Wuren T, Jeton F, Jin G, Marchant D, Richalet JP, Ge RL, Pichon AP. Role of glutamate and serotonin on the hypoxic ventilatory response in high-altitude-adapted plateau Pika. Respir Physiol Neurobiol 2015; 212-214:39-45. [PMID: 25890014 DOI: 10.1016/j.resp.2015.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 10/23/2022]
Abstract
The highland "plateau Pika" is considered to be adapted to chronic hypoxia. We hypothesized that glutamate N-methyl-D-aspartate (NMDA) and non-NMDA receptors, nitric oxide (NO) synthase, and serotonin are involved in hypoxic ventilatory response (HVR) in Pikas. We tested the effects of NMDA (memantine) and non-NMDA receptors (DNQX) antagonists, NO synthase inhibitor (L-NAME), and selective serotonin reuptake inhibitors (fluoxetine) on ventilation and HVR in Pikas. Ventilatory parameters were measured before and after drug (or vehicle) injections in conscious Pikas at their natural living altitude (PIO2 86 mmHg) and after a hypoxic challenge (PIO2 57 mmHg, 3 min) to assess the influence of peripheral chemoreceptor on HVR. Minute ventilation (VI) and tidal volume (Vt) increased during hypoxic challenge after vehicle injection, whereas the Ti/Ttot ratio remained unchanged. The increase in VI and Vt observed with vehicle at PIO2-57, when compared with PIO2-86, was inhibited after memantine and fluoxetine injection, whereas the DNQX injection increased HVR. At PIO2-57, L-NAME induced an increase in the Ti/Ttot ratio when compared with vehicle. Therefore, the glutamate through NMDA-R/AMPA receptor bindings and serotonin pathway are implicated at the peripheral chemoreceptor level in HVR in Pikas. However, NO influences the ventilatory pattern of Pikas at their habitual living altitude.
Collapse
Affiliation(s)
- Zhenzhong Bai
- Research Centre for High Altitude Medicine, Qinghai University Medical College, Xining, Qinghai, PR China
| | - Nicolas Voituron
- Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie & Poumon" EA2363, Bobigny, France; Laboratory of Excellence GR-Ex, PRES Sorbonne Paris Cité, Paris, France
| | - Tana Wuren
- Research Centre for High Altitude Medicine, Qinghai University Medical College, Xining, Qinghai, PR China
| | - Florine Jeton
- Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie & Poumon" EA2363, Bobigny, France; Laboratory of Excellence GR-Ex, PRES Sorbonne Paris Cité, Paris, France
| | - Guoen Jin
- Research Centre for High Altitude Medicine, Qinghai University Medical College, Xining, Qinghai, PR China
| | - Dominique Marchant
- Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie & Poumon" EA2363, Bobigny, France
| | - Jean-Paul Richalet
- Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie & Poumon" EA2363, Bobigny, France; Laboratory of Excellence GR-Ex, PRES Sorbonne Paris Cité, Paris, France
| | - Ri-Li Ge
- Research Centre for High Altitude Medicine, Qinghai University Medical College, Xining, Qinghai, PR China.
| | - Aurélien P Pichon
- Université Paris 13, Sorbonne Paris Cité, Laboratoire "Hypoxie & Poumon" EA2363, Bobigny, France; Laboratory of Excellence GR-Ex, PRES Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
4
|
Schwenke DO, Pearson JT, Kangawa K, Cragg PA, Shirai M. Exogenous ghrelin accentuates the acute hypoxic ventilatory response after two weeks of chronic hypoxia in conscious rats. Acta Physiol (Oxf) 2010; 200:279-87. [PMID: 20426772 DOI: 10.1111/j.1748-1716.2010.02142.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
AIM Ghrelin has been implicated as a modulator of numerous physiological pathways. To date, there have not been any studies describing the role of ghrelin in modulating the chemoreflex control of pulmonary ventilation. Yet the respiratory system impacts, at least to some degree, on virtually all homeostatic control systems. Chronic hypoxia (CH) can cause fundamental changes in ventilatory control, evident by alterations in the acute hypoxia ventilatory response (HVR). As ghrelin plays an important role in metabolic homeostasis, which is tightly linked to ventilatory control, we hypothesized that ghrelin may modulate HVR, especially following CH. METHODS Whole body plethysmography was used to measure the HVR (8% O(2) for 10 min) in male Sprague-Dawley rats (body wt ∼180-220 g) before and after 14 days of CH (CH=10% O(2)). During CH, rats received daily subcutaneous injections of either saline (control; n=5) or ghrelin (150 μg kg(-1) day(-1); n=5). The HVR was measured in another four rats that had received daily injections of ghrelin during normoxia for 7 days. RESULTS Ghrelin did not significantly alter basal ventilatory drive or acute HVR in normoxic rats. However, the acute HVR was accentuated following CH in ghrelin-treated rats compared with saline-treated rats. CONCLUSIONS These results describe the impact that ghrelin has in altering ventilatory control following CH and, although the mechanisms remain to be fully elucidated, provide guidance for future ghrelin-based studies interpreting physiological data indirectly related to the chemoreflex control of pulmonary ventilation.
Collapse
Affiliation(s)
- D O Schwenke
- Department of Physiology, School of Medical Sciences, University of Otago, Dunedin, New Zealand.
| | | | | | | | | |
Collapse
|
5
|
Teppema LJ, Dahan A. The Ventilatory Response to Hypoxia in Mammals: Mechanisms, Measurement, and Analysis. Physiol Rev 2010; 90:675-754. [DOI: 10.1152/physrev.00012.2009] [Citation(s) in RCA: 257] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The respiratory response to hypoxia in mammals develops from an inhibition of breathing movements in utero into a sustained increase in ventilation in the adult. This ventilatory response to hypoxia (HVR) in mammals is the subject of this review. The period immediately after birth contains a critical time window in which environmental factors can cause long-term changes in the structural and functional properties of the respiratory system, resulting in an altered HVR phenotype. Both neonatal chronic and chronic intermittent hypoxia, but also chronic hyperoxia, can induce such plastic changes, the nature of which depends on the time pattern and duration of the exposure (acute or chronic, episodic or not, etc.). At adult age, exposure to chronic hypoxic paradigms induces adjustments in the HVR that seem reversible when the respiratory system is fully matured. These changes are orchestrated by transcription factors of which hypoxia-inducible factor 1 has been identified as the master regulator. We discuss the mechanisms underlying the HVR and its adaptations to chronic changes in ambient oxygen concentration, with emphasis on the carotid bodies that contain oxygen sensors and initiate the response, and on the contribution of central neurotransmitters and brain stem regions. We also briefly summarize the techniques used in small animals and in humans to measure the HVR and discuss the specific difficulties encountered in its measurement and analysis.
Collapse
Affiliation(s)
- Luc J. Teppema
- Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Albert Dahan
- Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
6
|
Pichon A, Zhenzhong B, Favret F, Jin G, Shufeng H, Marchant D, Richalet JP, Ge RL. Long-term ventilatory adaptation and ventilatory response to hypoxia in plateau pika (Ochotona curzoniae): role of nNOS and dopamine. Am J Physiol Regul Integr Comp Physiol 2009; 297:R978-87. [PMID: 19641133 DOI: 10.1152/ajpregu.00108.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We assessed ventilatory patterns and ventilatory responses to hypoxia (HVR) in high-altitude (HA) plateau pikas, repetitively exposed to hypoxic burrows, and control rats. We evaluated the role of neuronal nitric oxide synthase (nNOS) and dopamine by using S-methyl-l-thiocitrulline (SMTC) inhibitor and haloperidol antagonist, respectively. Ventilation (Vi) was measured using a whole body plethysmograph in conscious pikas (n = 9) and low-altitude (LA) rats (n = 7) at different Pi(O(2)) (56, 80, 111, 150, and 186 mmHg) and in HA acclimatized rats (n = 9, 8 days at 4,600 m) at two different Pi(O(2)) (56 and 80 mmHg). The effects of NaCl, SMTC, and haloperidol on ventilatory patterns were assessed in pikas at Pi(O(2)) = 56 and 80 mmHg. We observed a main species effect with larger Vi, tidal volume (VT), inspiratory time/total time (T(i)/T(tot)), and a lower expiratory time in pikas than in LA rats. Pikas had also a larger VT and lower respiratory frequency compared with HA rats in hypoxia. HVR of pikas and rats were not statistically different. In pikas, SMTC induced a significant increase in Vi and VT for a Pi(O(2)) of 56 mmHg, but had no effect for a PiO(2) of 80 mmHg, i.e., the living altitude of pikas. In pikas, haloperidol injection had no effect on any ventilatory parameter. Long-term ventilatory adaptation in pikas is mainly due to an improvement in respiratory pattern (VT and T(i)/T(tot)) with no significant improvement in HVR. The sensitivity to severe acute hypoxia in pikas seems to be regulated by a peripheral nNOS mechanism.
Collapse
Affiliation(s)
- Aurélien Pichon
- Laboratoire Réponses Cellulaires et Fonctionnelles à l'Hypoxie, Université Paris 13, Bobigny, France.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Reeves SR, Simakajornboon N, Gozal D. The role of nitric oxide in the neural control of breathing. Respir Physiol Neurobiol 2008; 164:143-50. [DOI: 10.1016/j.resp.2008.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 08/10/2008] [Accepted: 08/11/2008] [Indexed: 11/16/2022]
|
8
|
Schwenke DO, Bolter CP, Cragg PA. Are the carotid bodies of the guinea-pig functional? Comp Biochem Physiol A Mol Integr Physiol 2006; 146:180-8. [PMID: 17107820 DOI: 10.1016/j.cbpa.2006.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 09/28/2006] [Accepted: 10/08/2006] [Indexed: 10/24/2022]
Abstract
We have previously observed that the guinea-pig appears to have a relatively poor ventilatory (V (E)) response to hypoxia, compared to other mammals. Therefore, in this study, we questioned the ability of the carotid bodies (primary peripheral chemoreceptors) in the guinea-pig to detect hypoxia. The ventilatory responses to poikilocapnic hypoxia (8% O(2)), poikilooxic hypercapnia (8% CO(2)), hyperoxia (100% O(2)) and cyanide (NaCN - 200 mug/kg, i.v.) were assessed before and after carotid body denervation (CBD) in anaesthetized guinea-pigs. Although CBD attenuated the V (E) responses to hypercapnia and cyanide, it had no effect on normoxic breathing or the V (E) responses to hypoxia or hyperoxia. In a separate group of guinea-pigs, nerve activity was recorded from single or few-fibre preparations of the carotid sinus nerve (CSN). Basal chemoreceptor activity could not be detected from any of the nerve preparations. NaCN and hypercapnia consistently provoked an increase in neural activity. In contrast, hypoxia never clearly increased activity in any of the single or few-fibre preparations isolated from the CSN. In conclusion, although the carotid bodies of the guinea-pig, like those of other mammals, are able to detect hypercapnia and histotoxic hypoxia and elicit a reflex increase in V (E), they are essentially hypoxia-insensitive. The latter may explain, at least in part, the relatively poor V (E) response to hypoxia shown by the guinea-pig.
Collapse
Affiliation(s)
- Daryl O Schwenke
- Department of Physiology, University of Otago, Dunedin, New Zealand.
| | | | | |
Collapse
|