An antagonist of growth hormone-releasing hormone protects against LPS-induced increase of bronchoalveolar lavage fluid protein concentration

Bronchopulmonary dysplasia is a leading cause of mortality and morbidity in preterm infants despite improved treatment modalities. Pentoxifylline, a phosphodiesterase inhibitor, inhibits multiple processes that lead to neonatal hyperoxic lung injury, including inflammation, coagulation, and edema. Using a preterm rat model, we investigated the effects of pentoxifylline on hyperoxia-induced lung injury and survival. Preterm rat pups were exposed to 100% oxygen and injected subcutaneously with 0.9% saline or 75 mg/kg pentoxifylline twice a day. On day 10, lung tissue was harvested for histology, fibrin deposition, and mRNA expression, and bronchoalveolar lavage fluid was collected for total protein concentration. Pentoxifylline treatment increased mean survival by 3 days ( P = 0.0018) and reduced fibrin deposition by 66% ( P < 0.001) in lung homogenates compared with untreated hyperoxia-exposed controls. Monocyte chemoattractant protein-1 expression in lung homogenates was decreased, but the expressions of TNF-α, IL-6, matrix metalloproteinase-12, tissue factor, and plasminogen activator inhibitor-1 were similar in both groups. Total protein concentration in bronchoalveolar lavage fluid was decreased by 33% ( P = 0.029) in the pentoxifylline group. Pentoxifylline treatment attenuates alveolar fibrin deposition and prolongs survival in preterm rat pups with neonatal hyperoxic lung injury, probably by reducing capillary-alveolar protein leakage.

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Isolation of rat trachea interstitial fluid and demonstration of local cytokine production in lipopolysaccharide-induced systemic inflammation

Journal of Applied Physiology ◽

10.1152/japplphysiol.00846.2007 ◽

2008 ◽

Vol 104 (3) ◽

pp. 809-820 ◽

Cited By ~ 14

Author(s):

Elvira Semaeva ◽

Olav Tenstad ◽

Athanasia Bletsa ◽

Eli-Anne B. Gjerde ◽

Helge Wiig

Keyword(s):

Bronchoalveolar Lavage ◽

Osmotic Pressure ◽

Protein Concentration ◽

Interstitial Fluid ◽

Bronchoalveolar Lavage Fluid ◽

Protein Pattern ◽

Fluid Phase ◽

Lavage Fluid ◽

Colloid Osmotic Pressure ◽

High Protein Concentration

Access to interstitial fluid from trachea is important for understanding tracheal microcirculation and pathophysiology. We tested whether a centrifugation method could be applied to isolate this fluid in rats by exposing excised trachea to G forces up to 609 g. The ratio between the concentration of the equilibrated extracellular tracer 51Cr-labeled EDTA in fluid isolated at 239 g and plasma averaged 0.94 ± 0.03 ( n = 14), suggesting that contamination from the intracellular fluid phase was negligible. The protein pattern of the isolated fluid resembled plasma closely and had a protein concentration 83% of that in plasma. The colloid osmotic pressure in the centrifugate in controls ( n = 5) was 18.8 ± 0.6 mmHg with a corresponding pressure in plasma of 22 ± 1.5 mmHg, whereas after overhydration ( n = 5) these pressures fell to 9.8 ± 0.4 and 11.9 ± 0.4 mmHg, respectively. We measured inflammatory cytokine concentration in serum, interstitial fluid, and bronchoalveolar lavage fluid in LPS-induced inflammation. In control animals, low levels of IL-1β, IL-6, and TNF-α in serum, trachea interstitial fluid, and bronchoalveolar lavage fluid were detected. LPS resulted in a significantly higher concentration in IL-1β and IL-6 in interstitial fluid than in serum, showing a local production. To conclude, we have shown that interstitial fluid can be isolated from trachea by centrifugation and that trachea interstitial fluid has a high protein concentration and colloid osmotic pressure relative to plasma. Trachea interstitial fluid may also reflect lower airways and thus be of importance for understanding, e.g., inflammatory-induced airway obstruction.

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Association of pituitary adenoma with neuronal christoma: A TEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016889x ◽

1994 ◽

Vol 52 ◽

pp. 232-233

Author(s):

Eva Horvath ◽

Kalman Kovacs ◽

B. W. Scheithauer ◽

R. V. Lloyd ◽

H. S. Smyth

Keyword(s):

Growth Hormone ◽

Pituitary Adenoma ◽

Pituitary Tumor ◽

Nervous Tissue ◽

Alternative Explanation ◽

Growth Hormone Releasing Hormone ◽

Cell Hyperplasia ◽

Releasing Hormone ◽

Secretory Neurons

The association of a pituitary adenoma with nervous tissue consisting of neuron-like cells and neuropil is a rare abnormality. In the majority of cases, the pituitary tumor is a chromophobic adenoma, accompanied by acromegaly. Histology reveals widely variable proportions of endocrine and nervous tissue in alternating or intermingled patterns. The lesion is perceived as a composite one consisting of two histogenetically distinct parts. It has been suggested that the neuronal component, morphologically similar to secretory neurons of the hypothalamus, may initiate adenoma formation by releasing stimulatory substances. Immunoreactivity for growth hormone releasing hormone (GRH) in the neuronal component of some cases supported this view, whereas other findings such as consistent lack of growth hormone (GH) cell hyperplasia in the lesions called for alternative explanation.Fifteen tumors consisting of a pituitary adenoma and a neuronal component have been collected over a 20 yr. period. Acromegaly was present in 11 patients, was equivocal in one, and absent in 3.

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