1. Depressed Hypoxic and Hypercapnic Ventilatory Responses at Early Stage of Lethal Avian Influenza A Virus Infection in Mice
- Author
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Kevin S. Harrod, Jianguo Zhuang, Peng Gao, Fadi Xu, and Zemmie Pollock
- Subjects
RNA viruses ,0301 basic medicine ,Pulmonology ,Physiology ,viruses ,Fluorescent Antibody Technique ,lcsh:Medicine ,Hypercapnia ,Mice ,0302 clinical medicine ,Zoonoses ,Medicine and Health Sciences ,Respiratory system ,Hypoxia ,lcsh:Science ,Pathology and laboratory medicine ,Mice, Inbred BALB C ,Carotid Body ,Multidisciplinary ,H5N1 ,Arteries ,Hematology ,Medical microbiology ,Body Fluids ,Infectious Diseases ,Blood ,medicine.anatomical_structure ,Influenza A virus ,Viruses ,Female ,Pathogens ,Anatomy ,medicine.symptom ,Research Article ,Viremia ,Biology ,Microbiology ,Tachypnea ,Virus ,03 medical and health sciences ,Respiratory Failure ,Virology ,Influenza, Human ,medicine ,Animals ,Humans ,Influenza viruses ,Lung ,Influenza A Virus, H5N1 Subtype ,Biology and life sciences ,lcsh:R ,Organisms ,Viral pathogens ,Hypoxia (medical) ,medicine.disease ,Viral Replication ,Microbial pathogens ,Biological Tissue ,030104 developmental biology ,Respiratory failure ,Respiratory Infections ,Immunology ,Cardiovascular Anatomy ,Blood Vessels ,Ganglia ,lcsh:Q ,Viral Transmission and Infection ,030217 neurology & neurosurgery ,Orthomyxoviruses - Abstract
H5N1 virus infection results in ~60% mortality in patients primarily due to respiratory failure, but the underlying causes of mortality are unclear. The goal of this study is to reveal respiratory disorders occurring at the early stage of infection that may be responsible for subsequent respiratory failure and death. BALB/c mice were intranasally infected with one of two H5N1 virus strains: HK483 (lethal) or HK486 (non-lethal) virus. Pulmonary ventilation and the responses to hypoxia (HVR; 7% O2 for 3 min) and hypercapnia (HCVR; 7% CO2 for 5 min) were measured daily at 2 days prior and 1, 2, and 3 days postinfection (dpi) and compared to mortality typically by 8 dpi. At 1, 2, and 3 dpi, immunoreactivities (IR) of substance P (SP-IR) in the nodose ganglion or tyrosine hydroxylase (TH-IR) in the carotid body coupled with the nucleoprotein of influenza A (NP-IR) was examined in some mice, while arterial blood was collected in others. Our results showed that at 2 and 3 dpi: 1) both viral infections failed to alter body temperature and weight, [Formula: see text], or induce viremia while producing similarly high lung viral titers; 2) HK483, but not HK486, virus induced tachypnea and depressed HVR and HCVR without changes in arterial blood pH and gases; and 3) only HK483 virus led to NP-IR in vagal SP-IR neurons, but not in the carotid body, and increased density of vagal SP-IR neurons. In addition, all HK483, rather than HK486, mice died at 6 to 8 dpi and the earlier death was correlated with more severe depression of HVR and HCVR. Our data suggest that tachypnea and depressed HVR/HCVR occur at the early stage of lethal H5N1 viral infection associated with viral replication and increased SP-IR density in vagal neurons, which may contribute to the respiratory failure and death.
- Published
- 2016