Isolation and Characterization of Lamellar Bodies and Tubular Myelin From Rat Lung Homogenates

Abstract

Three surface-active fractions which differ in their morphology have been isolated from rat lung homogenates by ultracentrifugation in a discontinuous sucrose density gradient . In order of increasing density, the fractions consisted, as shown by electron microscopy, primarily of common myelin figures, lamellar bodies, and tubular myelin figures . The lipid of all three fractions contained approximately 94% polar lipids and 2 % cholesterol . In the case of the common myelin figures and the lamellar bodies, the polar lipids consisted of 73% phosphatidylcholines, 9 % phosphatidylserines and inositols, and 8 % phosphatidylethanolamines. In the case of the tubular myelin figures, the respective percentages were 58, 19, and 5 . Over 90% of the fatty acids of the lecithins of all three fractions were saturated . Electrophoresis of the proteins of the fractions in sodium dodecyl sulfate or Triton X-100 revealed that the lamellar bodies and the tubular myelin figures differed in the mobilities of their proteins . The common myelin figures, however, contained proteins from both of the other fractions. These data indicate that, whereas the lipids of the extracellular, alveolar surfactant(s) originate in the lamellar bodies, the proteins arise from another source . It is further postulated that the tubular myelin figures represent a liquid crystalline state of the alveolar surface-active lipoproteins.

Detection and partial characterization of antibacterial factor(s) in alveolar lining material of rats.

“…Bronchoalveolar lavage fluid from [10][11][12] Sprague-Dawley rats (-30 ml) was freed of leukocytes and concentrated 20-fold by filtration through an Amicon membrane (10,000-mol wt exclusion). The concentrate was incubated with washed, log-phase pneumococci at 370C and serial cultures were performed (Fig.…”

“…This view is based (10). Lamellar bodies in surfactant were purified on a discontinuous sucrose density gradient as described by Gil and Reiss (11) and were tested for bactericidal activity on the day of preparation. Purified phospholipids and lysophospholipids were purchased (Sigma Chemical Co., St. Louis, MO).…”

Effects of Dietary Choline and N,N-Dimethylaininoethanol on Lung Phospholipid and Surfactant of Newborn Rats

“…In the CD-DM€ p u p of pup, tha specific activity of ~L l i n o kinme was lower nrrt only t h n t b t in tho CD group of pup but olwr t b t i n tha CS group. A plou~ibla sxplonotlon for this finding moy be rhe 1-t thot thir axyms war a~wryed i n the 100,CM g s~crrmtonn of h e lung h a - Table 4 show, thir rcrtio i n our pmpmtims was about 6.6 which ir ~mparable b, u Better h n , thaa r a p & for lung wtfactont isolated by other mothodr (13,14,19). Althwgh the auriaca octivlv of tha lrrrlated surfoctant w s M t m w r u d , ulhostr~tumlly, ow uudactant p+ratiorrr wara fad b carbin h t h thm lnhoce$lular -1 within the Immallar inclurian Mien) or well or Ib ~axhocallvl0r prewnt as tubular mftlin figmar 1141) swfoctont.…”

“…L I t h n of sirnilor sir= (10)(11)(12)(13)(14) were no signifiwnt differences i n tho concentmti~s of DNA, RNA end pmkinr betwoan h e vorlwr gm+s OF pyu. In pp delivcrsd by h a CD and CD-DME group o I dons, h e coraccntmtimr of sphingwnyalins md phosphotidyl cholinm ware !ewer t h those i n p u p dallvarad by dam Icd the CS diet (Toble 3).…”

Seven great achievements in pediatric research in the past 40 y

“…Investigations then centered on identifying the cells that synthesize and secrete pulmonary surfactant (42)(43)(44), and on characterizing its complex composition (45-47). Animal trials followed (48-50) with Fujiwara successfully treating premature infants with RDS using surfactant prepared from cow lungs (51).…”