Surface active materials from dog lung. I. Method of isolation

King, RJ; Clements, J. A.

doi:10.1152/ajplegacy.1972.223.3.707

Cited by 185 publications

(61 citation statements)

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“…During a single compression, the change in surface tension as the surface area of the balance decreased is related to the surfactant content of the aliquot layered onto the hypophase (3,16). The quantity of surfactant applied to the balance was quantitated by multiplying the surface area at 12 mN/m surface tension by 0.7 and using the known dilutions (16,22,24).…”

Section: Quantitative Surface-tension Measurementmentioning

confidence: 99%

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Augmentation of Pulmonary Surfactant Secretion by Lung Expansion at Birth

et al. 1979

Pediatr Res

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SummaryTo study the effect of lung expansion at birth on surfactant secretion, we delivered by hysterotomy 11 litters of rabbit pups at 30 days of gestation and divided them into three groups that were killed: 1) after 30 min air-breathing, 2) after 30 min nitrogenbreathing, and 3) after 30 min tracheal occlusion. Each group was compared to a littermate group killed at birth. Groups 2) and 3) continued respiratory efforts for 30 min despite progressive asphyxia. Six additional litters were pretreated with atropine; at delivery one-half of each litter was killed, the remaining pups were subjected to 30 min of hypoxic gas breathing. After sacrifice, alveolar surfactant was recovered by saline lavage and estimated quantitatively on a surface-tension balance. Surfactant concentration at birth was 1.40 + 0.22 mg/g dry lung and increased to 1.86 f 0.19 (k SEM) after 30 min air-breathing (P < 0.01). Also, surfactant was increased in the nitrogen-breathing pups (from 1.61 , f 0.35 in littermate controls to 2.41 f 0.58, P < 0.03), but not to a significant degree in the occluded group (1.34 + 0.33 vs. 1.41 k 0.28), or the atropine pretreated breathing pups (1.77 + 0.29 vs. 1.89 + 0.25). SpeculationThe data indicate that lung expansion at birth enhances surfactant release from intracellular sites and suggest that the vagus nerve mediates this effect. It is possible that the effect of maternal atropine may have clinical significance in preterm infants.Studies with newborn rabbits have shown that the percent of acetone precipitable lecithin in pulmonary lavage (12), pulmonary stability (29), and pulmonary lavage phospholipid content (25) increase after birth. These findings indicate that immediately after birth the secretion of surfactant into the alveoli is increased over and above the fetal secretion rate. With the onset of breathing, augmented surfactant secretion may be due to mechanical, neuronal, or humoral factors. Both lower surface tension and increased saturated lecithin in alveolar wash result from constant air-expansion of excised adult dog lungs (8), a mechanical stimulus. In rabbits, fetal injection of pilocarpine or P-adrenergic stimulants (e.g., isoxsuprine) also result in increased alveolar surfactant (5,6,7,18,30). These pharmacologic effects suggest autonomic control of surfactant secretion.To determine the physiologic stimulus for increased alveolar surfactant after birth, we measured quantitatively the surfacebreathing and the occluded pups differentiate the effects of asphyxia with and without gas ventilation of the lungs. The findings in the atropine pretreated groups establish that neural factors mediate surfactant secretion at birth. MATERIALS AND METHODS ANIMAL PROCEDURESTwenty litters of New Zealand white rabbits were used. The gestation of each litter was known to be 30 days within 3 hr (term = 31 days). In 11 litters, the does were sacrificed immediately before laparotomy with an iv infusion of 300 mg pentobarbital. Within 2 min, all the pups of a litter were gently delivered within their amnioti...

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Section: Quantitative Surface-tension Measurementmentioning

confidence: 99%

“…The quantity of surfactant applied to the balance was quantitated by multiplying the surface area at 12 mN/m surface tension by 0.7 and using the known dilutions (16,22,24). The surface balance measurement had a reproducibility of +7% on repeated determinations, and a minimum sensitivity of 6 pg surfactant.…”

Section: Quantitative Surface-tension Measurementmentioning

confidence: 99%

Augmentation of Pulmonary Surfactant Secretion by Lung Expansion at Birth

et al. 1979

Pediatr Res

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“…Surfactant protein A and D (SP-A and SP-D), which are expressed and secreted by alveolar type II cells (Walker et al 1986), could keep pulmonary alveoli from collapsing at the end of expiration (King and Clements 1972). In addition to their roles in surfactant homeostasis, SP-A and SP-D can participate in innate immune response and inflammatory processes (LeVine et al 2000).…”

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confidence: 99%

Polymorphisms in the Surfactant Protein A Gene Are Associated with the Susceptibility to Recurrent Urinary Tract Infection in Chinese Women

Liu

Liang

et al. 2010

Tohoku J. Exp. Med.

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Recurrent urinary tract infection (r-UTI) remains one of the common infections affecting adult female. Almost 27% of women developed a recurrent UTI within the 6 months (Foxman 1990) and nearly 50% of women developed a recurrence within the first year following the initial infection (Mabeck 1972). Clinical studies showed that only a fraction of r-UTI patients had obvious functional, anatomic and behavioral risk factors, which were considered to be strongly associated with an increased risk of r-UTI. Recently, genetic studies have reported the associations of polymorphisms within innate immune molecules such as Toll-like receptor 2 and 4 (TLR2 and TLR4) with r

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“…The isopycnic density of material in the lavage returns was determined by centrifuging the returns to sedimentation equilibrium in a continuous density gradient of sodium bromide. The gradient was formed from two solutions; one of density 1.174 g/ml, obtained by adding the required salts (10) to the lavage returns, and the other of density 1.008 g/ml. The resulting gradient was linear and ranged in density from 1.05 to 1.12 g/ml.…”

Section: Methodsmentioning

confidence: 99%