Inhaled Vitamin D: A Novel Strategy to Enhance Neonatal Lung Maturation.

INTRODUCTION: The physiologic vitamin D (VD), 1α,25(OH)2D3 (1,25D) is a local paracrine/autocrine effecter of fetal lung maturation. By stimulating alveolar type II cell and lipofibroblast proliferation and differentiation, parenterally administered 1,25D has been shown to enhance neonatal lung maturation; but due to the potential systemic side effects of the parenteral route, the translational value of these findings might be limited. To minimize the possibility of systemic toxicity, we examined the effects of VD on neonatal lung maturation, when delivered directly to lungs via nebulization. METHODS: One-day-old rat pups were administered three different doses of 1,25D and its physiologic precursor 25(OH)D (25D), or the diluent, via nebulization daily for 14 days. Pups were sacrificed for lung, kidneys, and blood collection to determine markers of lung maturation, and serum 25D and calcium levels. RESULTS: Compared to controls, nebulized 25D and 1,25D enhanced lung maturation as evidenced by the increased expression of markers of alveolar epithelial (SP-B, leptin receptor), mesenchymal (PPARγ, C/EBPα), and endothelial (VEGF, FLK-1) differentiation, surfactant phospholipid synthesis, and lung morphology without any significant increases in serum 25D and calcium levels. CONCLUSIONS: Inhaled VD is a potentially safe and effective novel strategy to enhance neonatal lung maturation.

Evidence of enhanced non-enzymatic generation of nitric oxide on the skin surface of acupuncture points: An innovative approach in humans.

The present study quantified total nitrate and nitrite (NOx-) collected from the skin surface along acupuncture points (acupoints) and determined whether non-enzymatic reduction of nitrate by bacteria is involved in chemical generation of nitric oxide (NO) on acupoints. A small plastic tube (0.5 x 7 cm) cut in half lengthwise was taped to the forearm or leg in 50 healthy volunteers. NO-collecting solutions with NO-scavenging compounds, hemoglobin or 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide, was placed inside the tubing attached to the skin surface for 20 min. The concentrations of NOx- in the collected samples were quantified by using chemiluminescence. NOx- concentration was significantly enhanced in four acupoints on the pericardium meridian and in two acupoints on the bladder meridian compared with those collected on non-meridian control areas. The time intervals of NOx- levels were significantly higher at the first 20 min of acupoint collection, but the concentrations were similar among the study groups collected at 20-40, 40-60, and 60-80 min. NOx- concentrations and numbers of bacteria colonies detected on the skin surface were markedly reduced by pretreatment of skin with sodium hypochlorite compared to water treatment. This is the first evidence showing that NO has been successfully quantified on skin acupoints by a non-invasive device in humans. We conclude that NO is physiologically released from the skin surface with a higher level at acupoints, and that the non-enzymatic reduction of nitrate by bacteria is involved in chemical generation of NO on skin acupoints in addition to l-arginine-derived NO synthesis.