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Free Radicals Can Kill You: Lavoisier's Oxygen Revolution

2010; Wiley; Volume: 24; Issue: 3 Linguagem: Inglês

10.1096/fj.10-0301ufm

1530-6860

Gerald Weissmann,

Various Chemistry Research Topics

Jacques-Louis David: Portrait (1788) of Antoine-Laurent Lavoisier (1743–1794) and his wife, Marie-Ann (1758–1836). Mme LAVOISIER: Imagine what it means to understand what gives a leaf its color! What makes a flame burn. Imagine! C. Djerassi and R. Hoffmann, 2001 (1) Oxygen is nothing other than the most salubrious and purest portion of the air, such that … it appears in an eminently respirable state more capable than the air of the atmosphere of sustaining ignition and combustion. Antoine-Laurent Lavoisier, 1775 (2) …though pure dephlogisticated air [oxygen] might be useful as a medicine, it might not be so proper for us in the usually healthy state of the body; for as a candle burns out much faster in dephlogisticated than in common air, so we might, as may be said, live out too fast, and the animal powers be too soon exhausted in this pure kind of air. A moralist, at least, may say, that the air which nature has provided for us is as good as we deserve. Joseph Priestly, 1775 (3) …there are good reasons for assuming that the changes produced by irradiation and those which arise spontaneously in the living cell have a common source—the OH and HO2 radicals. Denham Harman, 1956 (4) Illustration for Lavoisier's Traité Elémentaire de Chimie (1789) by Mme Lavoisier. “. … In regard to aging, I felt that there had to be a basic cause which killed everything. Further, this basic cause should be subject to genetic and environmental influences.” (6) It is no accident that Gerschman's and Harman's laboratories were funded by the Atomic Energy Commission. As Harman later observed, the work “was of particular interest in 1954 because of concern over possible nuclear war” (6). Well, thanks to the Cold War and the last 50-odd years of research in the area, we've learned that Priestly was right about that burning candle (3). We've learned that we do “live out too fast”, and our animal powers are indeed “too soon exhausted” when we are bombarded by oxygen-derived free radicals, whether generated from without or within our own bodies. The flood of publications dealing with “oxidative stress” has risen almost dramatically in the past few years. Scanning papers with oxidative stress as Key Words in The FASEB Journal for 2009, I found 63 of a total of 410, triple the number from 5 years ago (7). Is this a phenomenon unique to our journal? I checked out the broader literature on the Web of Science®. Sure enough, the oxidative burst had increased by a log order between 2005 and 2009 (Table 1). Over 15,000 articles about oxidative stress appeared in the literature in 2009, a 16-fold increase in only 5 years! In 2005, papers dealing with low oxygen (hypoxia) exceeded in popularity the hyperoxic condition, but by 2009, articles about oxidative stress beat out work regarding hypoxia, by 3:1. Publications on ever-popular actin and RNA showed no significant change (8). The papers we've published in The FASEB Journal last year tell us that experimental biologists now hold oxidative stress responsible for almost every aspect of development, disease, and bodily decline. Oxidative stress clocked in at third on the list of all Key Words, preceded only by “inflammation” and “apoptosis” (7). Indeed, conditions ascribed to inflammation and/or apoptosis were regularly ascribed to—you guessed it—oxidative stress (Table 2). It is evident that the oils, being composed of hydrogen and charcoal combined, are true carbono-hydrous or hydrocarbonous radicals; and, indeed by adding oxygen, they are convertible to vegetable oxides and acids according to their degrees of oxidation. (13) And that was before hydroperoxy and peroxy fatty acids were dreamt of. Antoine-Laurent Lavoisier and his wife Marie-Anne Lavoisier are depicted in the most beautiful image of scientific co-workers ever put on canvas. Jacques-Louis David's 1788 portrait of this unusual couple is not only an image of Enlightenment grace and grandeur but also a document of a work-in-progress for which both of the principals are responsible—the revolutionary Traité Elémentaire de Chimie of 1789 (13). It justifies the later appellation of Lavoisier as the “Father” and Mme Lavoiser as the “Mother” of modern chemistry (14). Lavoisier is shown with quill on paper looking up at his wife, as if to take dictation or suggestion. The instruments on the table and floor are those used by Lavoisier to give “the first accurate accounts of burning, respiration and rusting” (15). Mme Lavoisier is depicted with her arm on husband's shoulder while the folio behind her holds drawings for some of the 13 plates she fashioned for the Traité de Chimie. Lavoisier's mid-script attention to his wife alludes to her important translation of Kirwan's polemical treatise on phlogiston from English to French. In turn, her modest smile directed at the viewer—and the portraitist—suggests a strong student/teacher bond. Marie-Anne was an apt pupil of David: Her skillful student drawings, with David's comments, remain extant in the Paris museum, Musée des Arts et Métiers (16). The portrait also documents a concurrence of three revolutions: the American, the French, and the Chemical. It is set in the Arsenal of Paris, to which Lavoisier had been appointed as commissioner of the Royal Gunpowder and Saltpeter Administration. His charge, so to speak, was to greatly improve the purity and efficacy of French explosives. He fulfilled this task admirably: In aid of his American friends, Thomas Jefferson and Benjamin Franklin, he guaranteed the colonists a trusty supply of neat gunpowder to fight the Redcoats (17). Indeed, Franklin was a good friend of both Lavoisiers. Recovering from an attack of gout back in Philadelphia, Franklin wrote to Marie-Anne in 1783 to thank her for a portrait she had painted of him for its “great merit as a picture in every respect; but what particularly endears it to me, is the hand who drew it” (18). He was only one of Marie-Anne's many admirers, who included Gouverneur Morris, P. S. du Pont de Nemours, and Benjamin Thompson, Count Rumford. As Roald Hoffmann lamented: “There is no biography of Mme Lavosier. I think she deserves an opera” (15). Dispute has raged over which of the three chemists who came across oxygen between 1772 and 1778 deserves credit for the air of life. It is now agreed that a Swede discovered it first, the “fire air” of Carl Wilhelm Scheele in 1772 (19); a Brit published it first, the “dephlogisticated air” of Joseph Priestly in 1775 (3), and a Frenchman understood it first, the “oxygen” of Lavoisier in 1775–1778 (2). Recent studies (20) suggest that Lavoisier may have heard about Scheele's and/or Priestly's work directly or indirectly: But, there's surely credit enough for all three to split the “retro-Nobel” awarded by Carl Djerassi and Roald Hoffmann in their sparkling play, “Oxygen” (1). “Thus, while I thought myself employed only in forming a Nomenclature, and while I proposed to myself nothing more than to improve the chemical language, my work transformed itself by degrees, without my being able to prevent it, into a treatise upon the Elements of Chemistry.” (13) The treatise helped him to formulate the law of the conservation of matter: Nothing is lost in a chemical reaction. In perhaps his most vital work, he showed that living beings transform oxygen in the course of respiration, that they consume energy and generate heat, and that muscular exercise burns calories as a candle does. One can measure this process. He called it calorimetry (1). Alas, Lavoisier fell to the guillotine, not for his science but his business interests. Lavoisier was one of approximately two dozen partners—among them, Mme. Lavoisier's father—in a private, for-profit corporation, the Ferme général. The Ferme functioned as a crop-inspection and tax-collecting agency working on behalf of the crow. The proceeds from Lavoisier's share of Ferme général revenue are said to have paid for his experiments at the Arsenal (17). After July 14, 1789, Lavoisier became a staunch supporter of the liberal constitutional monarchy set up in response to the Bastille uprising. In the up-beat interregnum of 1790, he wrote to Benjamin Franklin of the two revolutions that were still in progress. Lavoisier, supported by his colleagues at the Academy of Sciences, had overthrown the reigning “phlogiston” theory. He exulted to Franklin: “Here then a revolution has taken place in an important part of human knowledge since your departure from Europe.” He was equally happy with the change in French political life: “After having brought you up to date on what is going on in chemistry, it would be well to speak to you about our political revolution. We regard it as done and without possibility of return to the old order” (21). Measurement of air moving in and out of the lung at Lavosier's laboratory at the Arsenal. From a drawing by Marie-Anne Lavoisier (ca. 1777). I denounce … the leader of the chorus of charlatans, Sieur Lavoisier, son of a land-grabber, apprentice-chemist, pupil of the Genevan stock-jobber [Necker], a Fermiergéneral, Commissioner for Gunpowder and Saltpeter, Governor of the Discount Bank, Secretary to the King, Member of the Academy of Sciences. (22) Together with the constitutional monarchy, the Ferme général was swept aside in the course of the Revolution. The radical Jacobins moved from mass protest to mass murder in what came to be called “the September massacres” of 1792. Lavoisier's laboratory at the Arsenal was shut forever. The Academy of Sciences dissolved shortly thereafter. In November 1793, Lavoisier, his father-in-law, and 26 others of the Ferme général were imprisoned and accused of “having plundered the people and the treasury of France, and of having adulterated the nation's tobacco with water, etc.” They were each found guilty after a 1-day trial and condemned to the guillotine on May 8, 1794 (22). “It took them only a moment to sever that head, and a hundred years perhaps will not suffice to produce another like it.” (24) Close enough: Albert Einstein was born in 1879.