CLINICAL ANATOMY OF THE EUROPEAN HAMSTER CRICETUS CRICETUS, L. LIBRARY JUN 1 6 1993 Mationsi Institutes of Heeltb For sale by the Superintendent of Documents, U.S. Government Printing Office Wastiington, D.C. 20402 Stoclt Number 01 7-042-00122-6 CLINICAL ANATOMY OF THE EUROPEAN HAMSTER Cricetus cricetus, L. By Gerd Reznik, D.V.M. Hildegard Reznik-Schiiller, D.V.M. Ulrich Mohr, M.D. Abteilung f iir Experimentelle Pathologic Medizinische Hochschule Hannover Hannover, West Germany Prepared For The Carcinogenesis Program Division Of Cancer Cause And Prevention National Cancer Institute Under Contract No. NOl-CP-55687 Edited by Peter Dodson, Ph.D. School of Veterinary Medicine University of Pennsylvania Philadelphia, Penna. 19174 With Editorial Assistance From Paul C. Walter, M.D. Ronald B. Levine Science Information Services Department The Franklin Institute Philadelphia, Penna. 19103 1979 FOREWORD The European hamster has proved to be a very useful animal for research in pulmonary carcinogenesis. However, prior to the publication of this handbook there has been little useful anatomical information on the animal. In 1974, Drs. Mohr, Reznik and Reznik-Schiiller of the Medizinische Hochschule Anatomical of Hannover produced an illustrated manuscript entitled "The European Ham- ster, An Anatomical Atlas." The manuscript was reviewed by Drs. Robert E. Habel and Howard E. Evans of the Cornell University Veterinary School, and in 1975 a contract was awarded by the National Cancer Institute to the Franklin Institute Research Laboratories (FIRL) for publication of the manuscript. Dr. Stephen Tauber of FIRL directed this project, with Dr. Paul Walter of FIRL editing the publication and Dr. Peter Dodson of the University of Pennsylvania School of Veterinary Medicine acting as anatomical consultant. This volume is not an all-inclusive atlas. Clinically relevant systems such as the respiratory system are emphasized and the anatomical orientation is focused on regions rather than systems. Details of the anatomy of the appendages or of other regions not covered in this volume may be obtained by writing to the authors. Likewise, emphasis is not given to microanatomy; however, when the his- tology of structures is described, it is noted in smaller typeface to alert the reader. Nomenclature was standardized by using the Nomina Anatomica Veter- inaria (N.A.V. 1968, 1973) as an authority, except insofar as it failed to denote structures unique either to rodents or hamsters (i.e., bursa buccalis). Each anatomical structure is introduced with its Latin (N.A.V.) term but the English term is used subsequently throughout the text. The German manuscript was translated in the authors' laboratory and edited by Dr. Waher and Dr. Dodson and Mr. Ronald Levine of FIRL. Dr. Walter also contributed significant segments of original text, especially with regard to limits and landmarks of thoracic and abdominal cavities, peritoneal relationships, and clinical considerations. Any editorial addition was read and approved by the authors who accept full responsibility for the text. The typing help of Francine Davis, Barbara Knox, Brenda Allen, and Clare M. Byrnes is most gratefully acknowledged. This monograph is part of Contract No. NOl-CP-55687 awarded by the National Cancer Institute, Division of Cancer Cause and Prevention, Dr. Thomas P. Cameron, Project Officer. Hi ERRATA P 38 Figure 2-33 Upside down Figure 2-34 P 41 Figure 2-40 Upside down P 42 Figure 2-42 Upside down P 147 Figure 5-11 Upside down P 159 Figure 5-32 Upside down PREFACE Since our research has been oriented for many years towards lung cancer, especially studies in etiology, we have been consistently seeking sensitive experi- mental animals. Such models should fulfill the following stipulations: 1. that lesions be induced within a survevable time period after administration of known carcinogens; 2. that well-differentiated tumor types (adeno- and squamous cell carcinomata) should originate in the respiratory tract; and 3. that no infectious diseases of the respiratory tract should interfere with the experimental results. About 10 years ago, our work was confined to the use of the Syrian golden hamster {Mesocricetus auratus) which had been recognized as the model for res- piratory tract carcinogenesis (Saffiotti 1969, 1974; Saffiotti, et ai, 1968; Althoff, et ai, 1971a, b; Nettesheim. 1972; Laskin and Sellakumar, 1975; Wynder and Hoffman. 1964. 1967; Delia Porta, et ai, 1958; Dontenwill and Mohr, 1961; Montesano and Saffiotti, 1968, 1970). This animal, however, frequently pre- sented with early tracheal papillomata, resulting in premature death by asphyxi- ation; consequently, the time required for induction of lung carcinomata, whose histopathologv would be significantly differential (adenocarcinoma, squamous cell carcinoma) could not be realized (Feron, et ai, 1972; Montesano, 1970; Lijinsky, et al., 1970; Haas, et al., 1973; Herrold and Dunham, 1963). More- over, the pulmonary tumors in this experimental animal have been suspected as originating from parts of tracheal papillomata ''transplanted'' to the lungs (Spit and Feron, 1975; Stenback, et ai, 1973; Creasia and Nettesheim, 1974). Studies on respiratory tract sensitivity to known carcinogens in Chinese hamsters led to mainly negative results, so that this animal species had to be rejected (Mohr, etai, 1966, 1967, 1970; Althoff, a/., 1971b; Reznik, a/., 1976a, b, c). VVe have finally verified that the European hamster, which lives wild in West Germany, fulfills the set stipulations for an animal model and that, in comparison to the .Syrian golden hamster (Fig. 0-1), offers additional advantages. With known nitroso- compounds, respiratory tract tumors have developed within a relatively short time of 13 weeks (Mohr, et ai, 1972); moreover, these tumors are for the most part well-differentiated. With corresponding doses of carcinogens, tumors are produced in all animals (100%) (Mohr, et ai, 1972, 1973, 1974a, b; Reznik-Schiiller and Mohr, 1975; R^mk, etal., 1977). The European hamster is comparable in size to the guinea pig and therefore offers sufficiently large anatomical dimensions for the execution of clinical test procedures (radiology, bronchography, cytology) throughout the period of tumor development (Freyschmidt, etai, 1975; Reznik, etai, 1975a; Eckel, etai, 1973, 1 974a, b, 1 975). The value of such studies in determining early tumor recognition cannor be under-estimated. Moreover, Cricetus cncetus is quite appropriate for special treatment techniques such as intratracheal and intrabronchial instillation of a carcinogen; this procedure can be performed without difficulty and much more easily than in other rodents. It also appears that the European hamster will prove to be better for studies on inhalation because its tidal volume is larger than that of the Syrian golden hamster (Kmoch, et al., 1975; Reznik, et al., 1975b, c; Kmoch, et ai, 1976). Moreover, it has been demonstrated in inhalation experi- ments with labelled cigarette smoke that about 30% more particulate matter is deposited in the lungs of the European hamster than in the Syrian golden hamster (Kmoch, et ai, 1975; Reznik, et ai, 1975b; Kmoch, et ai, 1976). Its size also means that biochemical studies to establish metabolites of carcinogens in the larynx, trachea and lungs are likely to be more successful than similar studies in th'e Syrian golden hamster, since the experimenter has significantly more tissue at his disposal. As is well known, C. cncetus is a hibernator (Fig. 0-2) (Kayser, 1961; Precht, et ai, 1973) and, according to the reports of zoologists, should live up to 8 years of age (Gaffrey, 1961; Zimmermann, 1965). Accordingly, we attempted to establish a breeding colony under laboratory conditions (Mohr, et ai, 1973; Reznik-Schiiller, et ai, 1974a). The problem of breeding has now been solved and we presently have a well established colony of seven generations with suffi- cient numbers of animals for experimental use. From all observations, the Euro- pean hamster has adapted quite well to laboratory life and, under standard conditions, the animals demonstrate no inclination toward hibernation. However, in the absence of hibernation, the lifespan of the hamsters may be shortened from the reported 8 years to 5 years. Nevertheless, this survival time still doubles the average span of the Syrian golden hamster. Of course, a longer survival time is a definite advantage for inhalation studies in carcinogenesis of the nasal and para- nasal spaces, larynx, trachea and lungs. Thus, our experimental animal has higher sensitivity to already known carcinogens and lives substantially longer than conventional laboratory rodents such as the mouse, rat and Syrian golden hamster. In addition, the European hamster, similar to the Syrian golden hamster, is free of infectious diseases of the respiratory tract. It is clear, then, that the European hamster is the animal of choice for studies in chemical carcinogenesis. Accordingly, yve are engaged in enlarging our breeding colony and maintain the hope that other scientists will also use this species in their investigations. We are making everv effort to place enough breeding pairs at the disposal of others. For studies in experimental carcinogenesis, it became apparent that a knowledge of the anatomy of C. cncetus would be especially useful. It must be possible to detail exactly the location of lesions to establish higher confirmation of species sensitivity to carcinogenic challenge. For this reason the present work on the anatomy