Immunocytochemical Localization of Vasopressinergic and Oxytocinergic Neurons in the Hypothalamus of the Rat by Monoclonal Antibodies

To investigate the distribution of vasorpressin and oxytocin neurons, tissue sections of the hypothalamus were examined by irnmunoperoxidase technique and light microscopy using monoclonal antibodies to ox~ ytocin and arginine vasopressin Our immunocytochemical investigations reveal both vasopressin and oxytocin neurons in the supraoptic nucleus(SON) , the paraventricular nucleus(PVN) , the arcuate nucleus, the suprachiasmatic nucleus, the accessory supraoptic nucleus, the perifornical area and the periventricular area. Perikarya of these two types neurons did not show distinct morphological differences at the level of light microscopy. Among these nuclei, they were mainly distributed in the SON and PVN, and the ratio of the number of vasopressin neurons to that of oxytocin neurons was 6 : 5 in the SON, and 1 : 2 in the PVN. So the SON and PVN are indistinguishable in that both cell types are present in both nuclei, but impressively vasopressin neurons were found only in the posterior half of the PV

Experimental Microvascular Grafts in Rats and Its Histological Studies.

Histopathological features of microvascular anasto! TIGses using "Invagination technique," end-to-end anastomoses and long term results of interposed venous grafts were studied in the femoral vessels of rat one to 12 months following surgery. The observation performed under light microscope, TEM and SEM. I. Histopathological features of the anastomotic site, which were repaired by "Invagination technique" and usual end·to·end anastomosis respectively, did not differ each other in the long term results. 2. Histological regeneration of anastomotic site did not accomplished by post·op 2 months and revealed active process was undergoing. 3. Endothelial lining of intima was nearly completed by 2 months at undamaged portion directly by suture materials. 4. In summary it may be said that histological examination of the specimen ranging in age from one to 12 months led general conclusion that venous grafts persist as living structure but undergo certain histological changes consisting of fibrous reinforcement

Study on the Inhibition of the Immune Response of the Neonatal Rat Spleen by the Azathioprine Administered during Pregnancy

The following experiment was performed to study the inhibition mechanism of the immune response in the neonatal rat spleen by azathioprine administered during pregnancy. The experimental animals were the two hundred neonatal rats which were born by sixty normal Sqrague- Dawley pregnant rats, of which 45 rats 8mgjkg of azathioprine were administered to orally at the 7th gestational day. Above two hundred experimental animals were divided into 6 groups as follows: Group 1: Neonatal rats to which T-dependent antigen, Sheep Red Blood Cells (SRBC) were injected intraperitoneally, born by normal pregnant rats. Group 2: Neonatal rats to which SRBC were injected intraperitoneally, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 3: Neonatal rats to which SRBC were injected intraperitoneally and thymus cells derived from outbred neonatal rats were injected intravenously, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 4: Neonatal rats to which T-independent antigen, Dextran was injected intraperitoneally, born by normal pregnant rats. Group 5: Neonatal rats to which Dextran was injected intraperitoneally, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 6: Neonatal rats to which Dextran was injected intraperitoneally and thymus cells derived from outbrcd neonatal rats were injected intravenously, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Antigen was injected intraperitoneally to above each group on the 1th, 8th and 12th weeks after birth and then, the spleen was resected on the 3rd and 7th days after injection of antigen for the plaque assay and histochemical studies. The following results were obtained: 1. Many plaque-forming cellsCPFC) were observed on the 3rd day after injection of antigen in all groups to which SRBC were injected, while many PFC were observed on the 7th day after injection of antigen in all groups to which Dextran was injected. 2. More PFC were observed in Group 1 than Group 2, and much more PFC were observed in Group 3. 3. There were no significant differences in number of PFC between Dextran·Groups(Group 4, Group 5 and Group 6). 4. There was strong tendency to recover the immunoIogicaI function with increasing age in SRBC· Groups(Group 1, Group 2 and Group 3). 5. Above results were in good accordance with those of histochemical observations. 6. It is strongly suggested that administration of azathioprine during pregnancy did suppress the development of fetal thymus, and that as a result of that suppression peripheral Tvhelper cells were depleted and consequently the formation of antibody was inhibited due to the insufficient colla' boration between T cells and B cells

Production of Monoclonal Antibody for Vasopressin

Monoclonal antibodies were produced against arginine vasopressin (AVP) by fusion of mouse myeloma cells with hyperimmune mouse spleen cells. Modified radioimmunoassay(RIA) was used to detect the presence of specific antibody in culture. Specificity of the antibody was further characterized by enzyme linked immunospecific assay(ELISA). This antibody was able to localize differentially the vasopressin neuron from the oxytocin neuron in tissue sections of the hypothalamus

Immunohistochemical and Electron Microscopic Studies on the Hormone Secretory Cells in the Developing Adenohypophysis the Human Fetuses

The hypophyses of human fetuses aged from 5 to 40 weeks were studied with the peroxidase-laheled antibody method and the electron microscope to investigate hormone secretory cells , and to ascertain the fine structural evidence for hormone synthesis. The pituitary gland excised were fixed in Bouins fluid and serial sections were made at 5p. Tissue sections were reacted with rabbit antisera to human growth hormone. prolactin. thyrotropin. and human chorionic gonadotropin respectively and then with peroxidase-labeled sheep anti-rabbit gamma globulin. followed by enzyme histochemical reaction. Observation were made under the light microscope. Some tissues were fixed in glutaraldehyde and osmium tetroxide. and stained with uranyl acetate and lead citrate for electron microscopic observation. The results observed were summarized as follows. 1. Somatotrophs were detected first at 10 weeks. mammotrophs at 18 weeks , thyrotrophs and gonadotrophs at 12 weeks respectively. but no hormone secretory cells were identified before 10 weeks 2. Somatotrophs and mammotrophs were found throughout the the pars distalis and most numerous in the lateral regions. and gonadoptrophs and thyrotrophs appeared chiefly in the posteromedian zone and in its superior portion 3. Average numbers of hormone secretory cells and reacting intensities of the cytoplasmic granules generally increased with advancing fetal age. 4. Electron microscopic findings of secretory cells were the presence of distinct granules, extensive development of rough surfaced endoplasmic reti culum and signs of granular formation in Golgi complex. and these findings strongly suggest that fetal adenohypophysis was producing hormones during its development

Histochemical Studies on the Adenohypophyses of Human Fetuses in Midpregnancy

Nineteen human fetal hypophyses ranging 5 to 8 months in gestational age were studied h istochemically to observe the changes of stainability. number of cells and distribution of chromophils in adenohypophysis with increasing fetal age. The pituitary glands were excised and fixed in Bouin's fluid. and serial sections were made at 5p.. Tissue sections were stained with Hematoxylin-Eosin. Masson's trichrome. Azocarmine'Aniline Blue-Orange G. PAS-Methyl Blue-Orange G and Aldehyde Fuchsin-PAS-Orange G. The results observed under ordinary light microscope were as follows. 1. Stainability was much lower than adult, but acidophils and basophils were identified and distinguishable from 5 months, and somatotrophs and marnmotrophs were distinguishable from 7 months. 2. Both acidophils and basophils increased in number with advancing fetal age particularly on 8 month, and acidophils exceeded basophils in increasing rate. 3. Acidophils were distributed mainly in the anterior portion of Rathke's pouch, but basophils in the peripheral portion of adenohypophysis

Effects of Imuran on the Development of Thymus in the Rat Fetuses

consecutive daily doses of azathioprine 5mg and 15mg/kg body weight on the 4-5th, 8-9th and 12-13th day of gestation respectively for the study of the effect of azathioprine on the development of fetal thymus and lymphatic organs of the rat. Fetal body weights. external anomalies and fetal death or resorptions were examined. Thymus, spleen and lymph node were studied histologically in the Methyl Green-Pyronin, PAS, H-E and Silver stains on the day of 20th of gestation and on the Ist and 2nd weeks of neonatal age after their weights were measured. The results observed under ordinary microscope were as follows. In comparison with control groups, experimental groups were: 1. Fetal body weights were decreased slightly, but the weights of thymus and spleen were decreased conspicuously. 2. In the thymus, the number of immature thyrnocytes were increased in the cortex, hence the contrast between cortex and medulla was obscure. 3. In the lymph node, the formation of lymphatic nodule is delayed, and medium-sized or large lymphocytes were increased in number diffusely. 4. In the spleen, the number of medium-sized and large lymphocytes were increased in the inner portion of periarterial lymphocyte sheath and the size of white pulp was decreased. 5. In the thymus, spleen and lymph node, mast cells increased in number and reticular fibers appeared more densely. 6. Among the experimental groups, the groups of drug administration on the 4-5th or 7-8th day of gestation were affected more severely than the groups on the l2-13th day of gestation

Light and Electron Microscopic Studies on the Intrauterine Development of Human Spleen

The spleens of human fetuses aged from 5 to 40 weeks were studied light and electron microscopically to investigate the development of the white pulp and the erythropoietic activities. The splenic primodium was first seen at the 5th week as a dense mass of mesenchymal cells on the left side of the dorsal mesogastrium. At the 9th week the spleen acquired it's characteristic form, and became progressively converted into loose. spongy reticular meshwork. At the 13th week there appeared many developing vessels and wide blood sinuses in the reticulum, and a number of erythrocytes and erythroblasts were present in or out of vessels. No significant level of erythropoiesis was observed until the 12th week although a few of erythroblasts were present in the capillaries of the splenic primodium. At the 13th week many mitotic ligures of erythroid cells were recognized, and the erythropoiesis continued until the end of gestation, being especially active during the middle third of fetal development. The differentiation of the white pulp has begun at the 13th week as the periarterial lymphatic sheath, which consisted of circumferentially arranged reticular cells and fibers around the central artery and loaded with large and medium sized lymphocytes, rnacrophages and a few erythrocytes. With advancing age, the white pulp increased in its size, and periarterial lymphatic sheath packed with small lymphocytes more predominantly. The primary follicle in the white pulp appeared first at the 21th week, but no germinal center was observed throughout gestation

Experimental Study of Pituitary Prolactin Cells on the Effect of Chlorpromazine and Bromocriptine Administration in Rats

Hypcrprolactincmia which is produced by pituitary tumor, lesions involving hypothalamo-hypophyscal tract and various drugs has important medical significance because of its close relationship with infertility. Among various drugs which produce hyperprolactincrnia chlorpromazine rapidly elevates blood level of prolactin by blocking the PIF receptor of the pituitary prolactin cells. Bromocriptine is a semisynthetic tripeptide ergot alkaloid and it has high specificity to the prolactin cells. It rapidly lowers blood prolactin level by stimulating the PIF receptor of the prolactin cells at the pituitary level and a few other mechanisms. Furthermore bromocriptine is known to inhibit growth hormone cells directly though still in a controversy. Chlorpromazine and bromocriptine were administered to 120 male rats grouped into 5. Pituitary, adrenals and testes were weighed. Pituitary was prepared for ligh t microscopic, electron microscopic and enzyme cytochemical study. By light microscope, the numbers of the acidophils were counted and sizes were measured for statistical analysis and by electron microscope the ultrastructural changes of the prolactin and growth hormone cells were examined. The results were as follows. 1. By light microscope there was no significant change in numbers of acidophils between each group but there was significant decrease in size of acidophils of combined chlorpromazine and bromocriptine group compared with control and chlorpromazine group. 2. By electron microscope there were severe depletion of prolactin granules and marked development of endoplasmic reticulum and Golgi complex in chlorpromazine group. In combined chlorpromazine and bromocriptine group, there was no significant change of prolactin granules but cellular organelles were markedly decreased in number. With continued bromocriptine administration, cell border and nuclear membrane of the prolactin cell became indistinct and most of the prolactin cells were atrophied with pyknotic nuclei. Growth hormone cells showed no significant changes in each group corn- 316 pared with control group. 3. Enzyme staining of the anterior pituitary showed decreased' activities of NADH and TPPase in chlorpromazine group and combined chlorpromazine and bromocriptine group