Napoleon Cybulski (1854 - 1919)

Between 1894 and 1895, through a series of experimental studies conducted on animal models alongside his assistant Władysław Szymonowicz, Cybulski demonstrated that the adrenal glands produce a biologically active substance that affects blood pressure and heart function. Simultaneously, they showed that the substance, which they named suprarenin (nadnerczyna), is present in the adrenal vein, from which it enters the circulatory system to exert its effects on the living organism. Today, we know that Cybulski and Szymonowicz, independently of two British scientists, George Oliver and Edward Schäfer, who were exploring the same research problem at the time, discovered adrenaline. For this reason, Cybulski and Szymonowicz should be considered co-founders of the field of global endocrinology.

The adrenal glands were first described by the Italian anatomist Bartolomeo Eustachi (d. 1527), whose name is still associated with the Eustachian tube, the structure connecting the middle ear's tympanic cavity to the upper part of the throat, found in humans and certain vertebrates. However, the function of the adrenal glands remained unknown for centuries, despite various attempts to elucidate their role in biological organisms. In the 17th century, Nathaniel Highmore (1613–1685) suggested that the adrenal glands "absorbed" excess fluid secretions from the large blood vessels nearby. Thomas Wharton (1610–1673), on the other hand, speculated that the adrenal glands extracted some substance from the nervous system and secreted it into circulating blood—a hypothesis surprisingly prescient in hindsight, though he lacked evidence to support it. Numerous other hypotheses were proposed, but none provided a conclusive solution.

In 1716, the Bordeaux Academy of Sciences announced a competition seeking definitive research on the adrenal glands' function. Despite multiple submissions, none met the committee's criteria. This is unsurprising, given that modern chemistry began taking shape only in the latter half of the 18th century, while experimental physiology emerged in the early 19th century. Moreover, the structural analysis of adrenal glands through microscopic studies was only resolved in 1852 by Albert von Kölliker (1817–1905). Just three years earlier, English physician Thomas Addison (1793–1860) demonstrated that degenerative changes in the adrenal glands were linked to specific clinical symptoms of an unknown disease, later termed Addison's disease. However, Addison could not explain its causes or mechanisms.

Charles Brown-Séquard took the next step in solving the mystery of the adrenal glands by showing that adrenal removal in animals invariably led to death. He concluded that the adrenal glands produced a substance essential for life but was unable to prove its existence.

Significant progress came in the early 1890s. British physician George Oliver, intrigued by experimental medicine, observed that an extract from adrenal glands caused a noticeable rise in arterial blood pressure. Being primarily a practitioner, Oliver reached out to Edward Schäfer, a professor at University College London. Initially skeptical, Schäfer's own animal experiments soon validated Oliver's findings, leading to a productive collaboration. They demonstrated that extracts from the adrenal medulla, when introduced into a living organism, significantly affected cardiac activity and arterial blood pressure. Additionally, they observed marked skeletal muscle responses, characterized by heightened tension (hypertension). Their first joint publication appeared in 1894.

Simultaneously, at the Physiology Department of the Jagiellonian University in Kraków, Professor Napoleon Nikodem Cybulski, along with his 24-year-old assistant Władysław Szymonowicz, was investigating adrenal gland functions. Szymonowicz conducted in-depth studies on the developmental anatomy and histological structure of adrenal glands. He then examined the effects of complete or partial adrenalectomy and the impact of administering adrenal extracts to healthy and adrenalectomized animals. Together with Cybulski, they experimented with various extracts, initially using water-based solutions and later alcohol-based ones. Their findings confirmed that adrenal extracts primarily affected the circulatory system, evidenced by well-documented changes in heart rate and blood pressure, as well as the respiratory system. It appears they were unaware of Oliver and Schäfer’s contemporaneous discoveries.

Cybulski and Szymonowicz advanced beyond their British counterparts, demonstrating that the same effects observed with adrenal extracts could be achieved using blood from the adrenal vein after gland stimulation. This confirmed that the adrenal glands contained a substance that traveled through the blood to produce the observed physiological responses. Using the Latin term suprarenalis ("adrenal"), Cybulski proposed naming this unknown factor suprarenin (nadnerczyna). In 1895, the Kraków researchers published their results and conclusions, which garnered significant interest and drew the attention of Oliver and Schäfer, who acknowledged their contributions in subsequent articles.

Today, we recognize that in observing and describing the effects of the mysterious "suprarenin," Cybulski and Szymonowicz were studying adrenaline, one of the primary hormones produced by the adrenal glands. The first step toward understanding the composition of "suprarenin" was taken in 1897 by American chemist and pharmacologist John Jacob Abel, who identified it as a compound with an active component he called epinephrine. However, he was unable to determine its structure. That breakthrough came from Abel’s collaborator, Japanese chemist Jokichi Takamine, who also gave it the new name adrenaline.

While elucidating the adrenal glands’ critical function was one of Cybulski's most remarkable scientific achievements, his other contributions to medicine are equally noteworthy. Together with his assistant Adolf Beck, he conducted extensive neurophysiological research. Beck became a pioneer in brain neurophysiology studies. Cybulski also achieved significant advances in characterizing electrocardiographic recordings under physiological and pathological conditions, collaborating with Marian Eiger.

Cybulski maintained a consistent interest in studying blood flow dynamics in the venous-arterial system and muscle electrophysiology. He also conducted detailed analyses of the swallowing mechanism and investigated the phenomenon of taste perception. Moreover, he explored the physiological underpinnings of hypnotism, a topic of considerable scientific interest in the late 19th and early 20th centuries.

Biography

Napoleon Cybulski was born on September 14, 1854, in the Krzywonosy estate, located in the Kobylnik municipality of the Vitebsk region. His father, Józef Napoleon, managed the estate, while his mother, Marcjanna (née Hutorowicz), dedicated herself to the household and to the early education of her son. Cybulski attended secondary school in Minsk Litewski, graduating in 1875. After passing his final exams, he enrolled in medical studies at the Military Medical Academy in Saint Petersburg. Even as a student, he displayed a particular interest in physiology. In 1877, he began working in the Department of Physiology under Professor Ivan Tarkhanov. Just three years later, in 1880, he earned his medical degree with distinction, officially conferred cum eximia laude (with exceptional praise).

This achievement opened the path for him to serve as a full assistant to Professor Tarkhanov. Five years later, in 1885, Cybulski obtained a doctorate in medicine by presenting his dissertation titled Issledowanija nad skorostju dwiżenija krowi posredstvom fotogiemotachometra (Investigations on the Velocity of Blood Movement Using a Photohemotachometer). In this work, he introduced an original device designed to accurately record variations in blood flow in vessels onto photographic plates. This innovation, called the photohemotachometer, was later refined and became a standard tool in physiological laboratories. While working on his dissertation, with Tarkhanov's support, Cybulski received an offer to take the Chair of Physiology at the Jagiellonian University. He accepted both the professorship and the chair.

This marked the beginning of the so-called Kraków School of Physiology. The dynamic and energetic professor attracted numerous individuals interested in science. Among Cybulski’s assistants and collaborators were notable figures such as Adolf Beck (1863–1942), later a professor of physiology at Lviv University; Władysław Szymonowicz (1875–1939), who became a professor of histology and embryology at the same institution; and Marian Eiger (1873–1939), who eventually held a professorship in physiology at Vilnius University. These were just a few among the many who regarded Cybulski as their mentor. His reputation earned him respect and trust not only among students but also within the academic community.

The university’s faculty twice entrusted Cybulski with the position of Dean of the Faculty of Medicine at the Jagiellonian University. In the 1904/1905 academic year, he was elected Rector of the university, and from 1905 to 1909, he served as Vice-Rector. As early as 1887, Cybulski became a corresponding member of the Academy of Learning, achieving full membership in 1891.

Beyond his scientific pursuits, Cybulski often addressed social issues. He was a moderate advocate of reform, supporting the idea of granting women access to university studies. Together with Professor Odon Bujwid and his wife, Kazimiera, he contributed to the establishment of the first girls’ secondary school in 1891, subsequently overseeing its development. He showed a keen interest in the welfare of the rural population, authoring an article on the nutritional challenges faced by peasants and closely examining the economic conditions of Galicia's villages. This engagement led him to accept the position of Chairman of the Supervisory Board of Agricultural Circles.

Author: Ryszard W. Gryglewski

References

• Beck, A., Napoleon Cybulski, Lviv, 1910.
• Pawlik, W. W., Konturek, S. J., Bilski, R., Napoleon Cybulski - Polish pioneer in developing the device for measuring blood flow velocity, Journal of Physiology and Pharmacology, 2006, 57 (Suppl.), pp. 107–118.
• Coenen, A., Zayachkivska, O., Adolf Beck: A pioneer in electroencephalography in between Richard Caton and Hans Berger, Advances in Cognitive Psychology, 2013, 9 (4), pp. 216– 221.
• Gryglewski, R. W., Cybulski Napoleon Nikodem, in Polish Petersburg. Retrieved from http://www.polskipetersburg.pl/hasla/cybulski-napoleon-nikodem.
• Kaulbersz, J., Napoleon Cybulski (1854–1919), in Grochowski, J. (ed.), Złota księga Wydziału Lekarskiego UJ, Kraków, 2000, pp. 281–292.
• Rola, R., Napoleon Cybulski – a pioneer of neurophysiology in Poland, Neurologia i Neurochirurgia Polska, 2011, 45 (1), pp. 88–91.