Prolongation of life of Tribolium confusum apparently due to small doses of x‐rays

Abstract

Prolongacihn de la vida de Tribolium confusum debida aparentemente a pequeiias dosis de 10s rayos X.En un trabajo publicado anteriormente (Journ. Exp. Zool., t. 22, m6m. 3, hbril 1917) se describieron experimentos que demuestran: 1) Que una cantidad suficiente de rayos X pueden acortar la vida de Tribolium confusum, y, 2 ) Que la duracihn de la vida despues de la accihn de dichos rayos puede expresarse por una f6rmula matemhtica, cuya derivacihn tebrica fu6 expuesta en dicho trabajo. El presente trabajo contiene 10s resultados de nuevos experimentos, 10s cuales demuestran : 1) Que es posible, aparentemente, el prolongar de un modo material la vida de Tribolium confusum susministrhdole pequefias dosis de rayos X. 2) Que la prolongacihn de la vida, cuando se administran diariamente pequefias dosis, es mayor que en el caso de administrarse dosis mayores de una sola vex. 3) El efecto letal de una dosis de rayos X es menor si se divide en una serie de dosis pequefias administradas diariamente que cuando se somete a1 organismo a la acci6n de una sola dosis mayor. 4) El autor describe un m6todo de anhlisis grAfico de 10s resultados obtenidos, mediante el cual el nl'lmero de causas de muerte puede determinarse por la cantidad de individuos muertos y tambidn estudiarse el efecto de un agente externo sobre cada una de estas causas. 5) Habiendose enipleado la misma clase de organismo durante todo el experiment0 10s resultados comunicados en el presente trabajo y en el publicado anteriormente demuestran que por una simple variacibn de la dosis, un agente puramente fisico (rayos X), puede producir a voluntad: a) una estimulacibn; b) un efecto destructivo que tiene Lugar solarnente despuds de un periodo latente y c) un efecto destructivo instantheo. Translation by JosO F. Nonidez Colurribia Uniwr6ity

HORMESIS: A Fundamental Concept with Widespread Biological and Biomedical Applications

“…This has been recognized for nearly a century as Davey [33,34] published the findings of an extremely well-designed series of experiments that demonstrated that X-ray exposure enhanced the lifespan of the confused beetle ( Tribulium confusum ). While the striking findings of Davey [33,34] would fail to inspire researchers to extend his research efforts in the first half of the 20th century, numerous investigators did develop an interest in aging research by the late 1950s, using insect models and ionizing radiation.…”

Radiation hormesis — fact or fiction?

“…He therefore suggested in 1919 that a low level of ionising radiation might stimulate rather than depress biological functions and health. Davey's view was based on experimental work which he had carried out and as a result of which he had been able to verify a prolongation of life in PriboIium confusum populations exposed to small doses of X-rays (Davey, 1919). Together with Atkinson, who had even earlier in 1898 made the observation that r6ntgen-irradiated algae grew faster than their non-irradiated controls (Atkinson, 1898;Webster, 1993), Davey may have been the first to speak in favour of the idea of radiation hormesis.…”

Hormetic Interventions in Aging

“…One of the earliest studies to show the life prolonging effects of irradiation were performed on flour beetle, Tribolium confusum, in which repeated exposure of beetles to low doses of Xrays (100-500 mA/min at 25 cm at 50 kV) reduced their death rates as compared with unexposed organisms [52,53] . Similar observations on the lifeextending effects of gamma-rays and X-rays on flour beetles were later reported by other authors [54,55] .…”