ABSTRACT
BACKGROUND: We previously demonstrated that neuronal nitric oxide synthase (nNOS) in epidermal keratinocytes is associated with epidermal permeability barrier homeostasis. OBJECTIVES: In the present study, we examined the contributions of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) to epidermal permeability barrier homeostasis. METHODS: We measured the barrier recovery rate after tape stripping of the epidermis of iNOS and eNOS knockout mice, and carried out electron-microscopic observation of the epidermis after acetone treatment. RESULTS: The barrier recovery rate of eNOS knockout mice was significantly faster than that of the wild-type control, while no significant difference was observed between iNOS knockout mice and wild-type mice. Electron-microscopic observation at 1 h after acetone treatment indicated that barrier recovery of both nNOS and eNOS mice was faster than that of wild-type mice, and lamellar body secretion was accelerated in both types of knockout mice. CONCLUSIONS: These results suggested that both nNOS and eNOS play roles in epidermal barrier homeostasis and lamellar body secretion.
Subject(s)
Epidermis/drug effects , Nitric Oxide Synthase Type III/pharmacology , Nitric Oxide Synthase Type II/pharmacology , Water Loss, Insensible/drug effects , Acetone , Animals , Epidermis/immunology , Epidermis/pathology , Immunohistochemistry , Mice , Mice, Knockout , Microscopy, Electron , Permeability/drug effectsABSTRACT
In lung transplantation, cold preservation is an important process. However, the mechanical changes in the airway and tissue during cold preservation, especially before reperfusion, are unknown. To test the hypothesis that the mechanical changes in the airway and lung parenchyma start during cold preservation, we investigated the mechanical properties of the rat lung as a whole organ and in excised lung strips. In the 0 h group, the lungs were not preserved. In the 9 and 24 h group, the lungs were preserved for 9 and 24 h at 4 degrees C. After preservation, we evaluated the static compliance (Csta) of the whole lung as obtained from the pressure volume curves (n=5 in each group). Also, we measured the input impedance taken by a computer-controlled small-animal ventilator (n=9 in each group). All data were analyzed using a homogeneous linear model, which includes airway resistance (Raw), tissue elastance (H), and tissue resistance (G). Hysteresivity (eta) was calculated as G/H. Moreover, the tissue elasticity (Eqs) obtained from the quasi-static stress-strain curves was compared. There was no significant difference in Csta among the three groups. Raw was significantly lower in the 24 h group than in the 0 h group (p<0.01). Eqs was significantly higher in the preserved groups than in the 0 h group (p<0.01). These results demonstrated that the changes in the three mechanical properties of the airway and the tissue started within 9 h of preservation.
Subject(s)
Cryopreservation , Lung Compliance/physiology , Lung/physiology , Animals , Cold Temperature , Extracellular Matrix/physiology , In Vitro Techniques , Lung Transplantation , Male , Rats , Rats, Wistar , Respiration, Artificial , Stress, MechanicalABSTRACT
BACKGROUND: Ischemia reperfusion (I-R) injury of the lung frequently occurs after cardiopulmonary bypass, pulmonary thromboendarterectomy, lung transplantation, and major pulmonary resection with vascular reconstruction. Mild hypothermia ameliorates ischemia reperfusion injury of the brain and the liver. However, the effect of mild hypothermia on I-R injury of the lung has not been investigated. METHODS: The lungs of Lewis rats underwent 80 min of ischemia followed by 60 min of reperfusion in an ex vivo perfusion model. The ambient temperature was maintained at either normothermia (38 degrees C, n=6) or mild hypothermia (35 degrees C, n=6) during the ischemia and reperfusion. RESULTS: Pulmonary shunt fraction, peak inspiratory pressure, mean pulmonary arterial pressure during reperfusion, and the wet/dry weight ratio of the lung tissue at the end of reperfusion in the mild hypothermia group were significantly (p<0.05) lower than those in the normothermia group. Total adenine nucleotide, adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate after reperfusion in the mild hypothermia group were significantly (p<0.05) higher than those in the normothermia group. CONCLUSION: Mild hypothermia attenuates I-R injury of the lung with maintained levels of intrapulmonary high-energy phosphate compounds after reperfusion, suggesting its beneficial effect on warm lung I-R in clinical settings.
Subject(s)
Hypothermia, Induced , Lung Injury , Reperfusion Injury/prevention & control , Adenine Nucleotides/metabolism , Animals , Cardiopulmonary Bypass/adverse effects , In Vitro Techniques , Lung/blood supply , Lung/physiology , Male , Pulmonary Circulation , Rats , Rats, Inbred Lew , Reperfusion Injury/etiology , Reperfusion Injury/physiopathologyABSTRACT
A DNA fragment of 550 bp was specifically amplified by PCR with primers based on the N-terminal sequence of the purified 3-hexulose-6-phosphate synthase from Methylomonas aminofaciens 77a and on that of a lysyl endopeptidase-derived peptide. Using this PCR product as a probe, a gene coding for 3-hexulose-6-phosphate synthase in M. aminofaciens 77a chromosomal DNA was cloned in Escherichia coli JM109. Sequencing analysis revealed that the gene encoding 3-hexulose-6-phosphate synthase contained a 624-bp open reading frame, encoding a protein composed of 208 amino acid residues with a calculated relative molecular mass of 21,224.
