Cricetus Research Articles

Reaction of hibernators to various low temperatures of the environment.

IN order to establish the conditions in which hibernators do not maintain their constant body temperature and enter hibernation in summer, the following experiments were made with European hamsters (Cricetus cricetus L.) in July and September 1959. Animals were exposed to various low temperatures and their oxygen consumption and rectal temperature recorded for 4 hr. Examples of the results of these experiments are given in Figs. 1 and 2, and mean values of the oxygen consumption in Table 1.

Body temperature, thyroid and adrenal cortex hamsters during cold exposure and hibernation, with comparisons to rats.

Since the early part of the twentieth century, many studies have been made to assess the activity of the endocrine glands in mammals before and after entrance into hibernation (Kayser, 1950, 1953). It has been frequently reported for the hibernating species that there is an involution of the anterior pituitary, thyroid and adrenal cortex during the autumn and that this condition persists during hibernation [e.g., marmot (Marmota), Coninx-Girardet, 1927; 13-lined ground squirrel (Citellus), Foster, Foster and Meyer, 1939; hedgehog (Erinaceus), Skowron and Zajaczek, 1947; European hamster (Cricetus) and dormice (Myoxus, Muscardinus), Kayser and Aron, 1950]. Kayser supports Adler’s (1926) hypothesis that hibernation is a direct result of a polyglandular depression in the autumn which reduces the ability of the animal to maintain its normal homeothermic adjustment when exposed to cold. The observations which form the basis for the Adler-Kayser hypothesis were made for the most part on animals which were kille...

EVOLUTIONARY STUDIES ON THE DISTRIBUTION AND DYNAMICS OF MELANISM IN THE HAMSTER (CRICETUS CRICETUS L.). II. SEASONAL AND ANNUAL CHANGES IN THE FREQUENCY OF BLACK HAMSTERS

EVOLUTIONARY STUDIES ON THE DISTRIBUTION AND DYNAMICS OF MELANISM IN THE HAMSTER (CRICETUS CRICETUS L.). II. SEASONAL AND ANNUAL CHANGES IN THE FREQUENCY OF BLACK HAMSTERS

Detection of Human Influenza Virus in Throat Washins by Immunity Response in Syrian Hamster (Cricetus auratus)

In a previous communication the serial passage of the human influenzal virus in the European hamster (Cricetus cricetus) was reported. While this hamster was shown to be susceptible to a recently isolated virus strain, it was not demonstrated, because of lack of material at the time, whether or not infection could be transferred directly from humans. This present report deals with the infection of the Syrian hamster (Cricetus auratus) from throat-washings of persons ill with epidemic influenza. Material. The washings were collected in buffered broth during the early months of 1939 from persons acutely ill with influenza. The presence of virus originally in these specimens had been demonstrated by the inoculation of ferrets. The washings had been preserved for 9 to 10 months in a low-temperature cabinet at −76°C when the inoculation of the hamsters was made. The hamsters employed were from 3 to 5 months of age and weighed approximately 100 g each. Method. Preceding inoculation, 1 cc of blood was withdrawn by cardiac puncture from each hamster. From 0.3 to 0.4 cc of unfiltered throat-washing was administered intranasally while the animal was under light ether-anesthesia. Twelve to 14 days after the intranasal inoculation a second blood sample was taken. The blood serum obtained before and following inoculation was then titrated for neutralizing antibodies against the PR8 strain of influenzal virus. Results. So far, 4 preserved washings obtained during the 1939 epidemic, but from separate localities, have been tested. All of these specimens were known to contain virus originally. None of the blood samples taken before inoculation showed any neutralizing effect upon the virus in a 1:2 serum-mixture, but samples taken 12 to 14 days after inoculation of the hamsters with each of these 4 washings all neutralized 1000 M.L.D. of the virus in dilutions above 1:32. Despite the immune response, these animals manifested no symptoms or gross pathological lesions which could be used as diagnostic criteria.

Serial Passage of the Human Influenza Virus in the European Hamster (Cricetus cricetus),

The study of viruses pathogenic for man is largely dependent on having an animal host suitable for experimentation. So far in the study of human influenza, ferrets and mice have proved to be best suited to this purpose, although both animals are far from being ideal. A number of others such as the hedgehog,1 white rat, guinea pig2 guinea pig foetus,3 Chinese mink, and David's squirrel4 have been shown to be susceptible only to varying degrees. However, search for additional suitable animals is being continued by most investigators engaged in the study of viruses, and the purpose of the present communication is to report briefly the results of the attempts to infect the European hamster (Cricetus cricetus)† with influenza virus.The strain of virus employed in these experiments was obtained 4 months previously from a person suffering from a rather typical attack of influenza. This virus had been identified immunologically as belonging to the group of human influenza viruses. In ferrets it produced character...

IV.—Hamster Remains from the Norfolk Forest Bed

Mr. A. Savin, of Cromer, has been kind enough to send me for examination a large number of small vertebrate remains which he has recently collected from the Upper Freshwater Bed of the Norfolk Forest Bed Series at West Runton. Among these there is one little specimen which deserves to be recorded, as it represents a genus not hitherto recognized in the ‘Forest Bed’. The specimen is a right maxilla with three grinders in place, indubitably belonging to the genus Cricetus; in size it is distinctly larger than the common Hamster Cricetus vulgaris (= C. frumentarius), which is the largest species of the genus living at the present day. Only once before has Cricetus been recognized in Britain, W. A. Sanford having identified from the Hutton Cave, Mendip Hills, remains of a small mouse-like species which he referred to Cricetus songarus.