The effects of sodium fluoride (NaF) on the monoaminergic, cholinergic and gabaergic systems were studied in mouse brain. The levels of dopamine (DA), 3, 4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid, norepinephrine, 3-methoxy-4-hydroxy-phenylglycol (MHPG), serotonin, 5-hydroxyindoleacetic acid (5-HIAA), acetylcholine (ACh) and gamma-aminobutyric acid (GABA) in the hypothalamus were measured by HPLC with an electrochemical detector. NaF increased the levels of MHPG, a main metabolite of NE and DOPAC, a main metabolite of DA, 2 hours after a single oral administraion at a lower dose (0.25㎎/kg). A higher dose of NaF (100㎎/ ㎏) increased not only the levels of MHPG, DA and DOPAC but also that of 5-HIAA, a main metabolite of serotonin, 2 hours after the administration. On the other hand, the same dose of NaF induced no changes in the levels of ACh and GABA. These results indicate that oral administration of NaF at a wide range of dose affects the monoaminergic metabolism in mice hypothalamus, suggesting the possibility that NaF changes the activities of the central monoaminergic system.

The effects of colchicine on the incorporation of ³H-glycine and ³H-serine into odontoblasts at various developmental stages was studied radioautographically.

The ddY mice, 14 days old, were twice given intraperitoneal injection of colchicine (5μg/10g b. w.). At 1, 24 and 48 hours after colchicine administration, the mice were injected with ³H-glycine and ³H-serine. They were sacrificed 10, 40 or 120 mins after isotope injection and their incisors processed for light microscopic radioautography. The numbers of silver grains over the cells and matrices increased with the differentiation of odontoblasts, but the drug did not appreciably affect the incorporation of ³H-glycine or the successive transport to the dentin matrices. On the other hand, the labeling with ³H-serine decreased with the differentiation of odontoblasts. The numbers of cells and matrices labeled with ³H-serine decreased after colchicine administration. These results suggested that the transport of ³H-glycine was independent on microtubules, but that of ³H-serine was closely related with microtubules.

The effects of retionic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25(OH)₂D₃) on bone formation were studied using calvarias from 18-day-old chick embryos cultured in a serum-free medium. In a preliminary experiment for determing the DNA and calcium and the DNA synthesis in a cultured half-calvaria and a devitalized calvaria, time-dependent increses in DNA and calcium contents were observed in the cultured bones, indicating that the culture system could be used for the investigation of modulating factors associated bone metabolism.

The addition of RA or 1,25(OH)₂D₃ to the media increased the synthesis of DNA, but decreased the synthesis of collagen in the cultured calvaria. The simultaneous addition of RA and 1,25(OH)₂D₃ to the media exerted a synergistic inhibitory effect against the synthesis of collagen. No significant difference in the uptake of ³H-tetracycline into the bone was observed by the addition of RA or 1,25(OH)₂D₃, suggesting that neither RA nor 1,25(OH)₂D₃ was effective for calcification in this culture condition.

The distribution and pathway of lymphatic vessels in the golden hamster tongue and the location of regional lymph nodes were investigated by stick-injection of Indian ink, the intravascular injection of Indian ink and impregnation with silver nitrate solution, and 5’-Nase-ALPase double staining. Lymphatic capillaries formed a netwok in the lamina propria of the tongue mucosa, and connective tissue papillaries were found to have a single lymphatic capillary. More lymphatic vessels were present in the muscular zones of the lateral middle portion of the dorsum of the tongue than the other areas. A lympahatic canal network was formed in intrermuscular spaces of the mylohyoid muscle, transmandibular muscle and the anterior belly of the digastric muscles. The collecting lymphatic vessels which occurred from the lymphatic canal network extended toward the regional lymph nodes, and the collecting vessels were divided into superficial and deep groups of vessels. Lymphatic vessels in the lateral anterior portion and the dorsal central and lateral portions of the tongue ran via the superficial and deep collecting vessels and were communicated to ipsilateral and contralateral submandibular lymph nodes respectively. Regional submandibular lymph nodes, 1~3 in number were present on each side. One parotid lymph node and deep cervical lymph node were observed on each side. The efferent lymphatic vessels from the submandibular lymph nodes joined the jugular lymphatic trunk, and extended toward the angle of the junction of the internal jugular and subclavicular veins.

At an anatomical training session conducted in 1990, a route anomaly of the maxillary artery was found on 44 sides in 22 Japanese cadavers. The left maxillary artery ran between the inferior alveolar and lingual nerves of the mandible. In this case, the maxillary artery branched at the base of the articular process of the mandible and ran anteriorly under the lateral pterygoid muscle. At the region of the mandibular ramus, the maxillary artery ran medially of the inferior alveolar nerve and then to the front of the lingual nerve. This pattern was type D of Fujita’s classification.