A solution of crystalline ribonuclease was injected intraperitoneally andintravenously into the blood stream of the mouse. A depletion of the ribonucleicacid together with a decrease of the calcium ash was observed in the corticalportion of the liver cell 12 minutes after the injection until recovery of normaldistribution 122 hours later. The possible association of calcium with ribonucleicacid in the cytoplasm constituents of the liver cell is discussed.

The celiac ganglia from 9 mature guinea pigs of both sexes were fixed in a mixture of 2％ glutaraldehyde and 2.5％ depolymerized paraformaldehyde. The SIF cells in cryostat sections were discerned out through their eatecholamine fluorescence induced by the fixative. These cells were processed through routine procedures for electron microscopy after or without incubation for acid phosphatase (AcP). The ultrastructure and AcP activity of these cells were observed under an H-600 electron microscope.The SIF cells were found to be present in clusters adjecent to fenestrated capillaries. The exocytosis of vesicular granules of SIF cells were seen on the surface of their cell membrane facing the capillaries. In addition, some dark SIF cells which were more osmiophilic and rich in mitochondria were discovered in this ganglion. These ultrastructural features of the SIF cells indicate that they may perform functions of an endocrine and/or paracrine nature.After one. hour incubation in a Gomori-typed medium at 37℃, some granules. besides the typical lysosomes display the AcP activity. Although the nature of the AcP-positive granules hasn't been elucidated a speculation is laid on that the presence of the enzyme on these granules may play a role of regulation in replacing the intragranular contents.

Fifty-two adult male rabbits, weighing 2～3kg, were divided into three groups. 1. Peptic ulcer were induced in 25 animals by injecting 0.3ml/kg of 40％ acetic acid into the submucosa of the stomach after laparotomy under aseptic conditions 2. 19 animals were operated as above but the same amount of normal saline were injcted instead of acetic acid 3. 8 normal rabbits were raised under the same conditions without any treatment and served as controls. The thyroid glands of three groups were taken at definite time intervals (1～40 days) after the operation. The right thyroids were prepared for cryostat sections after hexane quenching (-60℃) and subjected to enzyme histochemical studies. The left thyroids were fixed in Carnoy's fluid and subjected to histological and other histochemical studies. The following results were observed.The reactions of enzymes of follicular cells were weaker than the normal in the animals of the second group during the period of 3～21 days after the operation and injection of saline. The follicular ceils became flattened and follicular lumens increased in size. These changes began to show signs of recovery on the 28th day of the experiment. In the follicular cells of the first group of animals in which peptic ulcer developed after injection of acetic acid, the similar changes were observed as in the second groug of animals during the early period of 1～3 days after operation, but from 7 to 21 days after the operation, the reactions of Acid phosphatase, Succinate dehydrogenase, Glucose-6-phosphate dehydrogenase, Glycerphosphate dehydrogenase, Peroxidase, Adensine triphosphatase and Alkaline phosphatase were stronger and the sizes of follicular lumens were smaller, the colloid droplets were more numerous than those of the animals of the second group. These changes in the follicular cells of animals of the first group began to show signs of recovering toward norrnal on the 28 th day and became almost normal on the 40 th day after operation.These findings suggest that the thyroid follicular ceils were involved in the regulatory activities of the organism for the healing of the peptic ulcer.

The histological and histochemical changes in the C cells of the rabbit thyroid during experimental peptic ulcer were studied. Acetylcholinesterase was used as the marker enzyme to identify C cells. Forty-nine adult male rabbits were randomly divided into three groups: 1. In the experimental peptic ulcer group, 24 animals were induced to develop peptic ulcer by injecting 0.15 ml/kg of 40% acetic acid into the submucosa of the stomach after laparotomy under aseptic conditions. 2. In the saline control group, 18 animals were injected with 0.15ml/kg of normal saline into the submucosa of the stomach after laparotomy. 3. In the normal control group, 7 rabbits were raised under the same conditions as groups 1 and 2 without any treatment. Thyroid glands were removed at different time intervals (1-28 days) after the operation. The right thyroids were prepared for cryostat sections and subjected to enzyme histochemical studies. The left thyroids were fixed in Carnoy's fluid and subjected to histological and other histochemical studies. The findings were as follows.In the C cells from the normal control group, the reactions of acetylcholinesterase, nonspecific esterase and acid phosphatase were rather strong. Acetylcholinesterase can be taken as a specific marker enzyme for C cells. The reactions of thiamine pyrophosphatase, succinate dehydrogenase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase and ribonucleic acid were weak which suggested that normal C cells were a at a lower state of functional activity. In the saline control group, the histochemical changes showed that the C ceils were in an active functional state during the early period of the experiment, which may possibly reflect the response of C cells to the operation stress and wound healing. In the experimental peptic ulcer group, the reactions of acetycholinesterase, nonspecific esterase, acid phosphatase, succinate dehydrogenase, glucose-6-phosphate dehydrogenase, thiamine pyrophosphatase and ribonuclic acid of the C cells in the experimental peptic ulcer group were stronger than those of the saline control group 7-28 days after the operation. These histochemical changes of C cells duting this period may suggest that the C cells were active in function and perhaps participated in the regulatory activities of the organism during its recovery from the disease. In none of the three groups did the C cells show any conspicuous histological and morphological changes at any time in the experiment.

Serial cryostat sections of five hearts and seven atria of rats were prepared. Falck's fluorescent histochemical method, and histological staining methods wereutilized in succession on the same section. Small intensely fluorescent cells in rat's heart are round, oval or polyhedral in shape. A few of them possess processes. These cells are found in the heart in four major forms: dense spheroid groups, loosely associated clusters, linear alignment, and isolated cells.The number of small intensely fluorescent cell varies between 442-664 cells in the adult rat's heart. 86-92% of them are localized in subepicardium of atrium, especially several areas on the dorsum of atrium. No small intensely fluorescent cell was found in endocardium. The rest of these cells are scattered in other parts of the heart. The distribution areas of atrial nerve ganglia and small intensely fluorescent cells in subepicardium are similar. There are no such cells in some atrial ganglia and there is no relation between the number of these cells in the ganglion and its size. Parts of these cells are often found near the blood vessels. Small intensely fluorescent cells are not morphologically associated with the conduction system in the rat.

Monoamine oxidase and thiamine pyrophosphatase activities were demonstrated ultracytochemically in the celiac ganglion and adrenal medulla of the guinea pig by Shannon's and Novikoff's method respectively. Monoamine oxidase activity was found frequently on the nuclear evelope, and ocassionally in mitochondrial outer compartment and cell membrane of the small intensely fluorescent (SIF) cells of the ganglion. Similar Iocalizations were also observed in chromaffin cells of the adrenal medulla. In pricipal neurons of the ganglion, a large amount of products of the monoamine oxidase reaction were found on the endoplasmic reticulium in addition to the nuclear envelope and mitochondrial membranes. Abundant thiaminepyrophosphatase activity was seen at the tran-face of the Golgi complex in the pricipal neurons, in contrast to which, both SIF cells and chromaffin cells exhibited little thiamine pyrophosphatase activity. The results suggested that catecholamine metabolism and the mode of functional activity in the SIF cells were different from those in the pricipal neurons but similar to those in the chromaffin cells of adrenal medulla.

By means of the fluorescent histochemistry the small intense fluorescent (SIF) cells of the rat heart were identified under the fluorescent microscope, then the tissue containing these cells were prapared for electron microscopy. Ultrastracturally SIF cells were small in size and contained a lot of granules which can be distinguished into two types of electric density, and abundant number of mitocondria which appeared about 20 in each section of SIF cell at the nuclear level, and a large Golgi complex which consisted of 4-7 cisternae arranging in paralled array and some vesicles. Many single cisternae of rough endoplasmic reticulum were distributed in their cytoplasm. Adhesion zones and interdigitated processes were often observed between two SIF cells. Cholinergic nerves formed afferent synapses with SIF cells. SIF cells often occured near fenetrated capillaries. We found that the core of the granulated vesicles of some SIF cells were released into the perivascular space. These results indicated that SIF cells of the rat heart may have a local regulatory fnuction either as endocrinal or paracrinal cells.

The distribution of atriopeptins in the rat's heart was studied with immunohis-tochemical method. It was noticed that the immuno-reactive granules existed in most atriaI muscle cells. It was abundant in the cytoplasm about the paranuclear position. The cardiocytes of both atrial appendages gave an intense immuno-reaetion. Most cardiocytes of right atrium were more reactive than those of left atrium. Parts of atrial muscle cells which were distributed in the back of the left atrium, atrial septum and coronary sinus were negative in reaction.

In this paper the distribution of the atriopeptin-like immunoreactive substance in the ventricles of rat embryos of 13-19 days old was investigated by immunohistochemistry and electron microscopy. The results showed that atriopeptin-like immunoreactive granules were located around the nucleus in some cardiocytes of the ventricles of rat embryos. Most of these cells were distributed in the pectinated or trabecular structures in the luminal surface of left ventricle and a few of them in the myocardium of left and right ventricles. In the same embryo ventricle muscle cells contained less immunoreactive granules than those in the atria. Under electron microscope the atrial specific granule-like granules were found mainly near the Golgi complex. Some cells were devoid of such granules in cytoplasm. In the ventricles the distribution of the muscle cells containing atrial specific granule-like granules corresponds to the sites of muscle cells containing atriopeptin-like substance from the immunohistochemical study. The results suggest that the so-called "atriopeptin" is also present in some ventricular myocytes in rat embryos. The presence of atriopeptin-like substance may be related to the unique type of embryonic circulation.

Eighty adult male Wistar rats were randomly divided into three groups: 1. In the experimental peptic ulcer group, 35 animals were induced to develop peptic ulcer by injecting 0.05 ml/kg of glacial acetic acid (more than 99%) into the submucosa of the stomach after laparotomy under aseptic conditions. 2.In the saline control group, 35 animals were injected with 0.05 ml/kg of saline into the submucosa of the stomach after laparotomy. 3.In the normal control group, 10 normal animals without any treatment were raised under the same condition as group 1 and group 2. The thyroid glands of three groups were taken at definite time intervals (1-28 days) after the operation. The right thyroids were prepared for cryostat sections after hexane quenching (-60℃) and subjected to the histochemical studies of acid phosphatase (AcP), alkaline phosphatase(AIP), a-glycerophosphate dehydrogenase (a-GPD), succinate dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (G6PD), and nonspecific esterase (NsE). The left thyroids were fixed in Carnoy's fluid, stained with HE and subjected to histological study. The reactions of enzymes of the follicular cells in the group 2 were weaker than those in the group 3 (normal control) during the period of 2-21 days after the operation. The follicular cells became flattened and follicular lumens increased in size. These changes recovered to normal on the 28th day after the operation. In the follicular cells of group 1. In which peptic ulcer developed after injection of glacial acetic acid, the reaction of A1P was weaker than those in the group 3, but stronger than those in the group 2. The reations of a-GPD, SDH, and G6PD were stronger than those in the group 2, and as well as those in group 3. The reaction of AcP was stronger than those in the group 2 and group 3 during the 6-21 days after the operation. The follicular cells in the group 1 became flattened and the follicular lumens increased in size only during the period of 4-10 days after the operation and recovered on the 14th day after the operation. These findings suggested that the thyroid follicular cells of rat involved in the metabolic activities of the repair of gastric ulcer.