Orbeli, Leon Abgarovich

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ORBELI, LEON ABGAROVICH

(b. Tsakhkadzor, Russia, 7 July 1882;d. Leningrad, U.S.S.R., 9 December 1958)

physiology.

Orbeli was the son of Abgar losifovich Orbeli, a well-known jurist in Transcaucasia. After graduating from the Gymnasium in Tbilisi in 1899, he entered the Military Medical Academy in St. Petersburg. Orbeli’s general biological views were formed under the influence of the lectures of the zoologist N. A. Kholodkovsky and the histologist M. A. Lavdovsky. While still a student in the second course, Orbeli studied physiology and began to work in the laboratory of i. P. Pavlov. Here he carried out his first experimental research—the activity of pepsin iron before and after the severing of the vagus nerves (1903). For the next thirty-live years, Orbeli’s life and scientific career were closely connected with the work of Pavlov.

Following his graduation from the Military Medical Academy (1904), Orbeli became an intern at the Nikolai Hospital in Kronshtadt. His move to the Naval Hospital in St. Petersburg gave him the opportunity to continue his experimental research in Pavlov’s laboratory. Orbeli joined Pavlov at the very height of Pavlov’s research on conditioned reflexes. In OrbelTs dissertation, “Conditioned Reflexes of the Eye in Dogs” (1908), he showed that a change in the intensity of light could serve as a conditioned stimulus for a dog, even though the dog could not distinguish the color. On Pavlov’s recommendation Orbeli worked for two years with Hering in Germany, Langley and Barcroft in England, and at the Marine Biological Station in Naples.

Orbeli’s scientific career was spent in the leading Russian physiological centers. He worked in the physiology departments of the Institute of Experimental Medicine; the Military Medical Academy, where he was chairman of the department from 1925 to 1950; and the First Leningrad Medical Institute, where he was also chairman from 1920 to 1930. He also worked in the physiology laboratory of P. F. Lesgaft at the Petrograd Scientific Institute in the Biological Station in Koltushakh.

After Pavlov’s death Orbeli was the most prominent physiological scientist in the U.S.S.R.; he directed the I. P. Pavlov Institute of Physiology of the Academy of Sciences of the U.S.S.R., the Institute of Evolutionary Physiology and Pathology of Higher Nervous Activity in Koltushakh (now Pavlovo). In 1956 Orbeli organized the I. M. Sechenov Institute of Evolutionary Physiology (now the Institute of Evolutionary Physiology and Biochemistry of the Academy of Sciences of the U.S.S.R.).

Orbeli wrote more than 200 works on experimental and theoretical science. They embrace a varied range of problems in physiology and theoretical medicine. Most of them are grouped around the following subjects: physiology of the higher nervous activity and the sense organs; of the regularities of cerebrospinal coordination; physiology of the autonomic nervous system, the rapid development of which led to his creation of the theory of the adaptive-trophic role of the sympathetic nervous system in the organism (the classic Orbeli-Ginedinsky phenomenon, 1923); the theory of the physiological role of the cerebellum as regulator of the autonomic functions; the physiology Of kidney activity and the problem of pain; and environmental physiology particularly in deep-sea diving.

Orbeli was responsible for the development of evolutionary physiology, and he proposed special experimental methods of research to study regularities of the evolution of functions. Orbeli’s basic ideas in this direction are generalized in his program report “Basic Problems and Methods of Evolutionary Physiology” (1956). He created a large physiological school, and among his students were Y. M. Kreps, A. G. Ginctsinsky, A. V. Lebedinsky, and A. V. Tonkikh.

Orbeli’s scientific and organizational talent was highly appreciated by the Soviet government. In 1935 he was elected an active member of the Academy of Sciences of the U.S.S.R., and in 1945 he was awarded the title of Hero of Socialist Labor, He was also a member of various foreign academies.