The fine structure of the cells of the mouse peritoneum

Summary The cells of the peritoneum of the mouse have been examined with the electron microscope both by studying the gastro-splenic omentum and by washing the cells out of the peritoneal cavity. They comprise mesothelial cells, mast cells, lymphocytes and macrophages. The mesothelial cells were probably nearly all degenerate. The mast cells released granules which were phagocytosed by the other cells. The lymphocytes were either classical small lymphocytes, or rather larger cells similar to previously described immunoblasts. The macrophages varied considerably in size. Some were probably derived from the covering cells of the milk spots. They contained varying numbers of dense bodies, with the structure of lysosomes. A series of appearances was seen which suggested that these were synthesized in the granular endoplasmic reticulum. A gradation of structure was seen between lymphocytes and small macrophages.The gastro-splenic omentum consisted of two layers of mesothelium, in places fenestrated. The milk spots which were scattered throughout this structure were covered by cells similar to macrophages, and had a core of lymphoid cells in which ran a small blood vessel. The most notable difference between the mesothelial cells and the macrophages was the presence of many small caveolae at the surface of the mesothelial cells, and of larger vacuoles and indentations at the surface of the macrophages. Acknowledgements. I am grateful to Professor R. Barer for much advice and criticism, to Dr. G. A. Meek for guidance on electron microscopy, and to Miss M. Tune and Mr. M. Turton for photographic assistance.This work was supported by a grant from the Medical Research Council and by grants to the Department from the S.R.C., Nuffield Foundation and Unilever Limited.     

Changes in the fine structure of the human testicular interstitial cells after treatment with human gonadotrophins

Summary Study of the fine structure of the human interstitial cells after prolonged stimulation with human gonadotrophin reveals a striking increase in the quantity of the agranular endoplasmic reticulum. This is accompanied by an increase in the number of mitochondria which exhibit more extensive cristae, collections of intramitochondrial lipid and aggregations of electron-dense granular deposits. A rise is also evident in the number of lipofuscin pigment deposits and granular membrane-bounded bodies, both of which exhibit acid phosphatase activity. These changes after gonadotrophic stimulation are discussed in relation to steroid biosynthesis.In the pretreatment biopsies of these patients aged between 25–35 years, some interstitial cells contain intranuclear crystals which exhibit a hexagonal structure. The relationship of these intranuclear crystals to the cytoplasmic crystals of Reinke is discussed.The author is indebted to Dr. J. W. Johnstone and Dr. A. Long for the human material used in this study. Thanks are also due to Dr. H. P. Taft for helpful suggestions in the management of these patients, to Professor B. Hudson for the estimations of plasma testosterone and to Dr. J. B. Brown for the supply of human pituitary gonadotrophin and the estimations of urinary oestrogens. The technical help of Mr. T. Mezciems and the photographic assistance of Mr. J. S. Simmons F. R. P. S. and Miss S. Flett is gratefully acknowledged.     

The fine structure of the mouse adrenal X zone

Summary Electron microscopically the adrenal X zone was examined in the fourteen SMA female mice aged 40 and 70 days. At these ages, the X zone showed no signs of degeneration. The X zone cell was somewhat smaller than the permanent cortical cell.The mitochondria in the X zone cell were quite bizarre in shape, provided with tubules or cristae. Many intramitochondrial bodies very similar to the cytoplasmic lipid droplets were found in the X zone. A few lipid droplets and globules were also noticed in this zone. The lipid droplets may possibly be formed within the mitochondria.The light and dark cells were differentiated. For the light cells, scant mitochondria and tubular granular endoplasmic reticulum were characteristic in contrast to the abundant mitochondria and multi-lamellated agranular endoplasmic reticulum in the dark cells. The cellular variety in density was discussed with regard to steroid synthesis.The author wishes to express his sincere appreciation to Prof. H. Tauchi, The 2nd Department of Pathology, Nagoya University School of Medicine, for kind advice, to Dr. M. Hoshino for helpful suggestion, and to Mr. J. Aoki for excellent technical assistance.     

Histochemical localization of adenosinetriphosphatase in the testicular and pre-testicular nephridia of the Indian leech Hirudinaria granulosa (Savigny)

Summary Adenosinetriphosphatase has been histochemically demonstrated in the initiallobe cells and the central canal in its first round in the pre-testicular and testicular nephridia of the Indian leech Hirudinaria granulosa. The apical-lobe cells are positive in the pre-testicular and negative in the testicular nephridia. The functional significance of the enzyme at these sites has been discussed.I wish to express my gratitude to Dr. H. B. Tewari, under whose guidance the present work has been carried out. I am also indebted to Dr. M. L. Dhar, Director, Central Drug Research Institute, Lucknow; Dr. P. S. Krishnan, Professor of Biochemistry, University of Lucknow; and Dr. (Miss) Usha Gupta, Department of Pathology, University of Lucknow, for the hospitality which they have accorded me in their laboratories.     

Some aspects of the fine structure of the reticulo-endothelial system; the cells which clear colloids from the blood stream

Summary The macrophages in various sites in the mouse have been examined with the electron microscope in normal animals, and in animals which had recently received intravenous colloids. There was a general structural similarity at all sites. The most obvious common feature was the presence of small granules which stain with toluidine blue. These were of two types. One, the smaller had a finely granular substructure and may represent the primary lysosome; the other, the larger was heterogeneous, contains banded probably fibrillar material with a repeating pattern of 35–50 A, and may represent the residual body.Colloids given intravenously were cleared by phagocytosis by endothelial cells and endothelial macrophages, by leakage through patent intercellular junctions, and by phagocytosis by paravascular macrophages. Such clearance is commonly held to be a measure of reticulo-endothelial function. This measure is therefore clearly dependent on several cellular factors.I am grateful to Prof. R. Barer for his advice and criticism, to Dr. G.A. Meek for guidance on electron microscopy, and to Mrs. B. Romans and Miss M. Tune for technical and photographic assistance.This work was supported by grants from the M.R.C. and the University of Sheffield Tuberculosis Research Fund and by a grant to the Department from Unilever Ltd.     

On the alleged presence of non-argyrophile argentaffin cells in the human gastro-intestinal tract

Summary The relationship between the argentaffin and argyrophile cells of the human gastrointestinal tract has been studied, in foetal and adult material, by a technique involving the staining of sections first by an argentaffin method (Gomori-hexamine silver, Schmorl, Diazonium) and subsequently by an argyrophile method (Bodian). A comparison of the cells staining by the two methods shows that all argentaffin cells of the human gastrointestinal tract are also argyrophile and that there is no evidence to support the claim of Hellweg (1952) and of HamPerl (1952) regarding the presence of non-argyrophile argentaffin cells.W. H. O. fellow from the Department of Anatomy, Medical College, Rohtak, India. — I am very grateful to Professor J. D. Boyd and to the World Health Organisation for having made it possible for me to carry out this research at the Anatomy School, Cambridge. I am indebted to Dr. G. A. Gresham and his staff for their very willing cooperation in providing material from surgical resections. My thanks are also due to Mr. J. F. Crane for the photographs and to Mr. J. W. Cash and Mr. R. Smith for helpful discussions on staining techniques.     

Fluorescence studies on neural structures and endocrine cells in the pancreas of the cat

Summary With the use of the Falck-Hillarp histochemical technique for the detection of monoamines, nerve fibre fluorescence is observed throughout the tail of the pancreas of the cat and the arrangement and distribution of the nerve fibres can be studied in both the exocrine and endocrine tissue. In the exocrine pancreas, adrenergic nerve fibres innervate arterioles, larger veins and major pancreatic ducts. Adrenergic nerve fibres also appear to terminate on the non-adrenergic nerve cell bodies of the intrapancreatic ganglia. In the islets of Langerhans, adrenergic nerve fibres innervate both the endocrine cells and blood vessels. Some of the islet cells exhibit fluorescence with the Falck-Hillarp technique and these cells have been identified as alpha cells. In animals treated with reserpine, the fluorescence in nerve fibres and in alpha cells is absent.The author wishes to thank ProfessorG. C. Schofield and Dr.G. C. Smith for their encouragement and valuable criticism during the course of this study. The assistance of MissJ. Bennett and MissW. Kemp and the photographic help of Mr.J. S. Simmons, F.R.P.S., are gratefully acknowledged. The diagram was drawn by MissS. Flett.     

The histophysiology of antibody-forming sites in the marine toad

Summary The normal histologioal features of the lymphatic organs — pericardial nodes, jugular bodies, spleen, and kidney — of the marine toad, Bufo marinus, are decribed. The lymph nodes and spleen of the marine toad lack the compartmental organization of corresponding mammalian organs and contain relatively less internal connective tissue. The cellular stroma composed of reticulum cells and fixed macrophages plays a more important role in maintaining structural organization than do the connective tissue.Changes in the cellular composition of the lymphatic parenchyma were observed in animals immunized with bovine serum albumin suspended in Freund's complete adjuvant. In addition to an increase in the number of lymphocytes and the presence of lymphoid hemocytoblasts, cells occurred which possessed many of the morphological characteristics of mammalian plasma cells. These plasma cells, which exhibited positive fluorescent antibody reaction, were more abundant in the kidney than in the lymph nodes or spleen of an immunized animal.Granulomas developed at the site (gastrocnemius muscle) of injection of antigen in complete adjuvant, and similar cystic lesions arose in the kidney. Apparently, the antigen-adjuvant mixture found its way from the site of injection (gastrocnemius muscle) into the kidney, probably via the renal portal system, and established lesions in the kidney. Appreciable numbers of antibody-forming cells, or plasma cells, were found in the muscle granulomas and in the kidney lesions.The lymphoid tissue of the kidney is considered the principal site of antibody formation in the marine toad, Bufo marinus.This investigation was supported by grants HD-2614-1 and GM-11782 from the United States Public Health Service administered by Dr. Ronald R. Cowden and Dr. E. Peter Volpe, respectively.     

Mast cells in the lymphatics of the frog tongue

Summary In Rana catesbiana (10 adults) and Rana nigromaculata (2 adults), a number of mast cells are found within the lymphatics of the tongue. The round mast cells cluster in a monocellular layer in certain parts of the lymphatic walls and are either in close adhesion to the endothelial cells, or in contact with them with a slender cytoplasmic process.Microscopic examination of the lymph taken from the sublingual lymph sac reveals that the mast cells on the lymphatic wall can become free to move into the lymph only by vigorous massage of the tongue. Otherwise the lymph contains only a few free mast cells.The origin of the mast cells in this peculiar, supra-endothelial position is discussed. A figure that might suggest the migration of mast cells from the connective tissue into the lymphatics was encountered only rarely.This work is dedicated to Dr. Berta Scharrer on her 60th birthday.     

Further evidence for the proposed way of spermatogonial stem cell renewal in the rat and the mouse

Summary By means of ³H-thymidine and autoradiography it could be established that in rats and mice the A₁, A₂ and A₃ spermatogonia do not give rise to a significant number of stem cells.The number of A₀ spermatogonia was found to be circa 20% of the number of A₀+A₁ spermatogonia in the rat and circa 10% in the mouse.The author wishes to thank Prof. Dr. M. T. Jansen and Dr. M. F. Kramer for helpful discussions and Mr. J. G. van Essen for technical assistance.     

Microbial production of xylitol from D-xylose using Candida tropicalis

Candida tropicalis DSM 7524 was used to produce xylitol from d-xylose. The fermentation conditions were optimized during continuous cultivation. The strain employed showed no great dependence upon temperature in a range between 30° C and 37° C. It achieved its best yield of xylitol from d-xylose at a pH value of 2.5. Such low pH values allow non sterile cultivation, which is a major economic factor. With an oxygen uptake rate of 0.8–1 ml oxygen per litre culture medium, the C. tropicalis produce xylitol at a yield of between 77% and 80% of the theoretical value. Higher yeast extract concentrations prevent the conversion of d-xylose into xylitol. d-xylose acts as a growth inhibitor in higher concentrations. The maximum xylitol yield was reached at a d-xylose concentration of around 100 g/l. In a non sterile batch culture with substrate shift 220 g/l xylitol were produced from 300 g/l d-xylose at a xylitol productivity rate of 0.37 g/(lh). In order to increase the specific yield, C. tropicalis was immobilised on porous glass and cultivated in a fluidized bed reactor. In a continuous non sterile cultivation with immobilised cells 155 g/l d-xylose produced 90–95% g/l xylitol with a productivity of 1.35 g/(lh).Mr. S. S. da Silva was a visiting scientist to the GBF. He was supported by a scholarship from the National Council of Scientific and Technological Development, Brasilia, Brazil (CNPq).We also would like to gratefully acknowledge the support of Prof. Dr. Michele Vitolo of the University of Sao Paulo, and the Centre for Biotechnology and Chemistry, Lorena, S. P. Brazil, in particular the Department of Fermentative Process.We are grateful to Prof. Rainer Jonas, head of the International Cooperation between Germany/Brazil for the helpful discussions and Dr. Heinrich Lönsdorf (GBF) for the Scanning electron micrographs.Dedicated to the 65th birthday of Prof. Dr. Fritz Wagner.     

Electron microscopic observations of lung alveolar epithelial cells of normal young mice,with special reference to formation and secretion of osmiophilic lamellar bodies

Summary Using the electron microscopy and electron microscopic histochemistry the authors studied the lung alveolar epithelial cell of normal young mice.Type II cell of the alveolar epithelium has characteristically numerous osmiophilic lamellar bodies. The lamellar boies are formed in the cytoplasmic vesicle, and never originate from the mitochondrion. These bodies have abundant acid phosphatase activity in their limiting membrane therefore it is considered to be lysosomal origin, but the mitochondria have no such enzyme activity.The body which is newly formed in the cytoplasmic vesicle grows up to the large lamellar body as a result of an accumulation of the fibrous dense substance, migrates to the free margin of the type II cell of alveolar epithelium, and then is discharged into the alveolar lumen as a merocrine type secretion.Acknowledgement is given to Professor Dr. Y. Sano and Professor Dr. H. Fujita, Department of Anatomy, and Assistant Professor Dr. S. Fujita, Department of Pathology, for their kind advice and criticism.     

Light-microscope studies of the cytology of the adenohypophysis of the white-crowned sparrow,Zonotrichia leucophrys gambelii

Summary Adenohypophyses from more than two hundred white-crowned sparrows of both sexes and different ages, and from different periods of their annual reproductive cycle, have been used for this investigation. In addition to examination of these normal birds, we have also studied the adenohypophyses of 23 castrates and 24 controls held in different photoperiodic conditions.Cytologically the pars distalis of the adenohypophysis of the white-crowned sparrow is typically avian with distinct cephalic and caudal lobes, each with characteristic cell-types.Four basic cell-types, the acidophils, basophils, amphophils, and chromophobes, have been identified in the pars distalis by means of Matsuo tetrachrome and Matsuo modified PAS-methyl blue staining methods.Three types of acidophils, orange, red, and small, are confined to the caudal lobe of the pars distalis. Their possible functions are discussed.Light basophils (PAS-light red cells) and deep basophils (PAS-deep red cells) are equally distributed in both lobes. It is suggested that basophils may be involved in gonadotropic function since their appearance correlates well with the annual gonadal cycle and photoperiodic stimulation of gonadal growth and with the results of castration.The amphophils or PAS-purple cells (aldehyde-fuchsin positive) are found only in the cephalic lobe. Their probable function is discussed.Two types of chromophobes, specific and ordinary chromophobes, have been observed. The specific chromophobes are found only in the cephalic lobe and are similar to the Kernhaufen described by Romeis (1940). The ordinary chromophobes are similar to those of the pars distalis of other avian species and of mammals.The castration cells are found in both lobes of the photosensitive castrates under natural photoperiodic conditions as well as in those subjected artificially to photostimulation (20-hour daily photoperiods). Similar cells have also been observed in the pars tuberalis of the castrated photostimulated birds.The relations of the rostral and caudal groups of the portal vessels to the cell-types found in the cephalic and caudal lobes are discussed.Dedicated to Professor Dr. Y. Kato, Department of Anatomy of the Domestic Animals, Kyushu University, Fukuoka, Japan, and to President Dr. H. Mimura, Shinshu University, Matsumoto, Japan, in honor of their retirement.The investigation reported herein was supported by a research grant (5RO 1-HEO7240 NEUA) from the National Institutes of Health to Professor Vitums, by funds for biological and medical research made available by State of Washington Initiative Measure No. 171 to Professor Vitums; by a Research Career Development Award (5K3 AM-18, 370) from the National Institutes of Arthritis and Metabolic Diseases to Professor King; and by a research grant (5RO 1 NB 06 187) from the National Institutes of Health to Professor Farner. The senior author is greatful to Professor Dr. Hideo Murai and Doctor Yasukuni Watanabe, Department of Animal Science, Shinshu University,Ina,Japan, for their cooperation and support in this investigation. We wish to thank Mrs. Sumiko Sumida for technical assistance, and Miss Kathleen Reinhardt for the preparation of the drawings.     

Nuclear membranous whorls

Summary Membranous whorls have been seen in the nuclei of peritoneal and testicular cells which had been subjected to various experimental manoeuvres. It seems likely that this is an early manifestation of cell degeneration which is demonstrated readily only by glutaraldehyde fixation, and to that extent can be regarded as a glutaraldehyde artifact. Acknowledgements. This work was supported by grants from the Medical Research Council, and the University of Sheffield Tuberculosis Research Fund, and by a grant to the Department from Unilever Ltd.I am grateful to Professor R. Barer for his advice and criticism, to Dr. G. A. Meek for guidance on electron microscopy, to Dr. E. J. Clegg for permission to use material from joint experiments. Technical and photographic assistance was provided by Messrs. P. GarLick and L. Murgatroyd and by Miss M. Tune.     

On the glycocalyx,the external coat of the plasma membrane,of some secretory cells

Summary The free surface of epithelial cells of secretory organs (human placenta, lactating mammary gland of the rat, choroid plexus of man and rat) and of the accessory organs of the genital tract of the male rat is characterized by a plasmalemmal differentiation named glycocalyx or surface mucous coat. This structure is built up by filamentous or globular substructures.Two main ultrastructural types of the glyeocalyx were observed: 1) The filamentous type such as in the rat epididymis, which resembles the cat intestinal glyeocalyx (Ito, 1965) and that one of human transitional epithelium (Monis and Zambrano, 1968), and 2) The globular type, as observed in the lumen of the lactating mammary gland of the rat.Sialic acid was demonstrated histochemically in the luminal glyeocalyx of all organs studied. In addition, the glyeocalyx of acinar cells of the lactating mammary gland contains sulfate and phosphate groups which were identified by histochemical technics, using enzymatic digestion procedures, suggesting the chemical heterogeneity of this glyeocalyx.Present investigations follow the working hypothesis that the complex carbohydrates of glycocalyces become part of the product of activity of secreting cells.We thank Mr. Luis Iwakawa, Miss Silvia Falcón, Miss Elsa M. Orgnero for technical help, Miss Graciela Aliaga for secretarial assistance. Photography by Mr. H. Magnani. Dr. Hugo F. Carrer cooperated in the initial stages of this investigation.The authors acknowledge the use of the electron microscope of the Department of Pathology, Córdoba University Medical School, for which they thank Prof. E. Mosquera and Dr. E. Hliba. Dr. Hliba photographed picture number 4.     

Changes in the functional activity of macrophages of the skin and regional lymph node after exposure of albino rats to total deep hyperthermia

In the experiments performed on white male rats (150-170 g of body mass) effect of total deep hypothermia has been studied in macrophages of the skin and regional suprascapular lymph node of various localization: Langerhans cells of the epidermis, histiocytes of the derm and hypoderm, macrophages of medullary sinuses, interdigitating cells of T-zones in the lymph node. After narcotization the animals are cooled with the rate 1 degree C per 5 min up to the rectal temperature of 18 degrees C. They are kept at this temperature for 2 h, and then are warmed with the same rate up to 37 degrees C. Actively phagocytizing macrophages of the skin and lymph node are revealed by their adsorption of trypan blue. The Langerhans and interdigitating cells of the lymph node are revealed by means of the ATP-ase method. After the cooling effect functional activity of macrophages with various localization increases. For the Langerhans cells it is manifested as a greater amount of the cells and their processes, for the interdigitating cells--as an elevated ATP-ase activity in 7 and 30 days after the experiment. Dermal histiocytes and macrophages of the lymph node sinuses respond to the cooling with an increasing adsorption of tripan blue. Amount of the cells, that adsorb the dye also increases. A conclusion is made that after the hypothermal effect protective-barrier properties of the dermal region increase.     

Magnitude and modulation of pancreatic β-cell gap junction electrical conductance in situ

The parallel gap junction electrical conductance between a -cell and its nearest neighbors was measured by using an intracellular microelectrode to clamp the voltage of a -cell within a bursting islet of Langerhans. The holding current records consisted of bursts of inward current due to the synchronized oscillations in membrane potential of the surrounding cells. The membrane potential record of the impaled cell, obtained in current clamp mode, was used to estimate the behavior of the surrounding cells during voltage clamp, and the coupling conductance was calculated by dividing the magnitude of the current bursts by that of the voltage bursts. The histogram of coupling conductance magnitude from 26 cells was bimodal with peaks at 2.5 and 3.5 nS, indicating heterogeneity in extent of electrical communication within the islet of Langerhans. Gap junction conductance reversibly decreased when the temperature was lowered from 37 to 30°C and when the extracellular calcium concentration was raised from 2.56 to 7.56 mm. The coupling conductance decreased slightly during the active phase of the burst. Activation of adenylate cyclase with forskolin (10 m) resulted in an increase in cell-to-cell electrical coupling. We conclude that -cell gap junction conductance can be measured in situ under near physiological conditions. Furthermore, the magnitude and physiological regulation of -cell gap junction conductance suggest that intercellular electrical communication plays an important role in the function of the endocrine pancreas.The authors thank Dr. Arthur Sherman for sharing his insights on in situ coupling measurements, and for helpful discussions throughout the work. DM acknowledges partial support by a National Institutes of Health training grant to the Johns Hopkins University, Department of Biomedical Engineering (5 T32 GM7057). This work was supported in part by a National Science Foundation PYI award (ECS-9058419) to NFS.     

An electron microscope study of spermiogenesis in Spirorbis (Laeospira) mörchi Levinsen (Polychaeta)

Summary 1. In the hermaphroditic polychaete Spirorbis (Laeospira) mörchi, early spermatids develop in clusters within the coelom of the male segments. The cells within a single cluster are all in the same stage of development and are connected by an extensive cytoplasmic bridge system. 2. The acrosome forms in a single lamella of the Golgi apparatus which bears a close association to the plasma membrane. The final position of the acrosome is at a point considerably removed from the site of formation. 3. The nuclear changes culminating in condensation and elongation of the head are described. A rearrangement of cytoplasmic microtubules occurs simultaneously with nuclear elongation. 4. Redundant nuclear envelope, resulting from nuclear volume reduction, is pinched off in the form of four vesicles. The latter structures are lost with the residual cytoplasm. 5. Pour spherical mitochondria elongate to become incorporated into the middle-piece. A rearrangement of microtubules also occurs simultaneously with mitochondrial elongation. Cytoplasmic microtubules are absent from the fully formed sperm.This investigation was made possible through a Postdoctoral Fellowship from the National Science Foundation, 44150. — I wish to express my gratitude to Dr. John Luft for the training I received in the techniques of electron microscopy. Dr. James Koehler and Dr. Daniel Szollosi are thanked for their many helpful suggestions.     

Histochemical demonstration of monoamine oxidase in the hypothalamo-hypophysial system of the tree sparrow and the rat

Summary Localization of monoamine oxidase (MAO) was investigated essentially according to the method of Glenner et al. (1957) in the hypothalamo-hypophysial system of the tree sparrow and the rat. The hypothalamic neurosecretory cells of both species showed relatively weak MAO activity. A similar localization of MAO activity was observed in the median eminence of both species: (1) slight or no MAO activity was observed in the ependymal layer, (2) relatively strong activity was revealed in the tissue just beneath the ependymal layer, (3) strong activity was revealed in the outer layer, particularly in the tissues surrounding capillary loops of the primary plexus. It is suggested that an adrenergic mechanism functions in the median eminence. In the pars nervosa, strong reaction was observed in the rat, while a weak reaction occurred in the tree sparrow. However, the color and the size of formazan crystals deposited in the rat pars nervosa differed from those in the hypothalamus. As a whole, the distribution of the neurosecretory material differed from the localization of MAO activity in the hypothalamo-hypophysial system. It is discussed that the neurosecretory neuron is not adrenergic but cholinergic.Aided by Grant A-3678 from the United States Public Health Service. The authors are indebted to Dr. S. Kambara, Zoological Institute, and Dr. H. Hirano, Department of Anatomy, University of Tokyo, for their valuable advice, and also to Assoc. Prof. S. Yamamoto, Department of Hygiene, University of Tokyo, for making available some facilities. They also wish to thank Dr. L. M. Barbato, University of Illinois, and Mr. K. Asami, National Institute of Radiological Sciences, Chiba, and Mr. Suzuki, Research Laboratory, Chugai Pharmaceutical Company Ltd., Tokyo, for the kind supply of MAO inhibitors.     

Some studies on the fluorescence of mast cells after paraformaldehyde treatment

Summary Air dried peritoneal fluid and tissue spreads from rat, mouse, hamster, rabbit, guinea pig, cat, chicken, and frog were treated with paraformaldehyde (pCHO) at 80 ° C for 1 hr. Only rat and mouse mast cells fluoresced. In the rat, mast cells fluoresced whether present in vascular or avascular areas of mesentery, in fat depots, or in peritoneal fluid. Photographs were obtained by fluorescence microscopy, the preparations were then stained and the same fields rephotographed in white light. Comparison of the photographs showed that every fluorescent rat mesentery mast cell also stained with acidified toluidine blue and with Astrablau; a few fluorescent cells did not stain with toluidine blue and an occasional cell that did not fluoresce stained with this dye or with Astrablau. Paraformaldehyde depressed somewhat toluidine blue, inhibited strongly Astrablau, and abolished Alcian blue binding. It had no effect on the staining of purified heparin in model experiments.Reserpine administration in the rat did not prevent visualization of mast cells by the pCHO method.These experiments indicate that all rat mast cells contain serotonin, regardless of cell size (age ?) or site and suggest that no massive, cyclic release of this amine occurs either physiologically or in response to reserpine treatment.Some of the experiments for this paper were carried out in the laboratory of Dr. G. Bloom, Department of Cell Research and Genetics, Karolinska Institutet, Stockholm, Sweden, (September and October, 1963). I wish to acknowledge the help and cooperation of the members of his staff, and especially Dr. Martin Ritzén, whose open, warm, efficient and enthusiastic manner enabled me to accomplish much in a relatively short time. Availability of darkroom facilities to pursue much of the work in the laboratories of Dr. W. Bargmann, Anatomisches Institut, Neue Universität, Kiel, Germany and of Dr. R. Robineaux, Hôpital St. Antoine, Paris, is also gratefully acknowledged. Grant support was furnished by the American Heart Association (62 G 118) and NSF (GB-4166) (to the author), by NIH 5 T 1 GM 102, and by the Swedish Medical Research Council (to Prof. B. Uvnäs and Dr. G. Bloom).This paper is dedicated to Dr. Berta Scharrer on the occasion of her 60th birthday.