Diazo-reaction positive substance observed in the cortex of Chattonella antiqua.

In order to investigate the causative factors responsible for removal of mucous coat from the gill lamellae of young yellowtail, Seriola quinqueradiata by red tide, diazo-reactions were employed for planktons and their media. The concentration of NO2- in the medium containing the raphidophyceae, Chatonella antiqua (ca 2000 cells/ml), was 0.70 +/- 0.05 (mu g/ml +/- SEM). In addition, diazo-reaction positive substances (NOx) which may degenerate the mucous, was highly concentrated in the cortex (perikaryon) of Chattonella antiqua. Morphologically, mucocysts, and chloroplats were likewise present in the cortex. Mucocysts were packed with fine fibrous content. Histochemically, the mucocysts were stained with PAS and had an abundance of nitrogen oxides (NOx). We observed discharge of the fibrous material from the mucocysts. These results suggest that when Chattonella antiqua is passing between the gill lamellae, NOx discharged from the mucocysts may act on the mucous, leading to the degeneration and concomitant removal of the mucous coat from gill lamellae.

[Effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane) on the synthesis of acetylcholine in anemic hypoxia].

Pretreatment of mice with 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane) protected against effects of anemic hypoxia. Befemelane delayed the loss of the righting reflex (from 17.8 +/- 1.3 to 21.9 +/- 1.2 min, p less than 0.05) and death (from 19.6 +/- 1.3 to 23.3 +/- 1.1, p less than 0.05) in mice with anemic hypoxia (induced with NaNO2). Pretreatment with bifemelane ameliorated the reduction in the synthesis of acetylcholine from labeled precursors in anemic hypoxia. Namely, it reduced the inhibition of acetylcholine synthesis from labeled choline (from 3.8 +/- 0.5 to 9.4 +/- 1.2 pmole/mg protein at 30 mg/kg, p less than 0.01), but not significant at 15 mg/kg. However it (15 mg/kg) caused a significant increase in the incorporation of [U-14C] glucose into acetylcholine compared to the value for hypoxic animals (from 5 +/- 0.5 to 9 +/- 1 dpm/mg protein, p less than 0.001). Under normal conditions, concentrations of acetylcholine and glucose in the brain were significantly increased by the 30 mg/kg of bifemelane, while the synthesis of acetylcholine from choline was significantly decreased. This reduction of synthesis might be caused by the increased acetylcholine concentrations in the brain. Fifteen mg/kg of bifemelane significantly increased the concentrations of glucose, 14C-acid soluble fraction and the synthesis of acetylcholine from [U-14C] glucose. In the in vitro experiments, cholinesterase activity was significantly inhibited by the bifemelane (1.47 microM). However, its inhibitory effects were about 1/9000 of physostigmine sulfate, which might be too weak to increase the acetylcholine concentration in the brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of 3-acetylpyridine on local cerebral glucose utilization.

Local cerebral glucose utilization was observed in mice treated with 3-acetylpyridine (3-AP), one of the nicotinamide antagonists. This drug resulted in loss of pyramidal cells and gliosis restricted almost exclusively to Spielmeyer's resistant sector (area CA3) in the dorsal hippocampus. On the other hand, the most striking feature in the autoradiographic observations was that optical density in the impaired CA3 region of the dorsal hippocampus was significantly increased (P less than 0.01). Therefore, when the 2-deoxyglucose method is employed under pathological conditions, one must pay attention to these glial reactions.

Distribution of 35S-taurine in rat neonates and adults. A whole-body autoradiographic study.

The distribution of 35S-taurine in rat neonates and adults was investigated by wholy -body autoradiography. The neonates (4-day-old) were frozen in dry-ice hexane at 30 min, 1, 3 and 6 h after an intraperitoneal injection of 35S-taurine, whereas survival intervals for adult rats were 1 and 3 h. Whole-sagittal sections of the frozen rat, obtained by using a cryostat microtome were dried in situ and autoradiographed. In rat neonates and adults, 35S-taurine was mainly accumulated in the renal cortex, urine, feces, liver, eye (lens, vitreous fluid, retina), hypophysis, thymus, adrenal glands, nasal mucous membrane, salivary glands, gastric mucosa, small and large intestinal mucosa, choroid plexus, myocardium and sebaceous glands. In the rat neonate, such regions as the olfactory bulb, cerebrum, and cerebellum showed relatively high optical density.

Effects of 3-acetylpyridine on the adrenal medulla of the mouse.

In the present work, the effects of 3-acetylpyridine (3-AP) on the adrenal medulla were investigated for biochemical and morphological changes. Adrenaline- and noradrenaline-storing cells treated with 3-AP one day previously had lost almost all their granules. A large number of lipoid droplets appeared in the cytoplasm. At the same time, the concentrations of adrenaline and noradrenaline cells were significantly decreased below control values (P less than 0.01). However, these significant changes were ameliorated 19 days after 3-AP treatment. Morphologically and biochemically, the adrenaline- and noradrenaline-storing cells had recovered completely at 35 days.

Local cerebral alterations in [14C-2]deoxyglucose uptake following memory formation.

In order to show changes in the local cerebral glucose utilization during an avoidance task, dry-autoradiography with [14C]deoxyglucose was employed in the present work. The following regions showed increased radioactivity following the avoidance task: nucleus ventralis thalami of the pars medialis and lateralis thalami, corpus striatum, nucleus periventricularis hypothalami, paraflocculus, stratum lacuno-moleculare, and nucleus lateralis septi. Among other regions, the stratum lacuno-moleculare of area CA1 and CA2 of the hippocampus showed increased activity apparently related to the memory formation.

Studies on regional blood flow of the mouse using whole-body autoradiography of 14C-iodoantipyrine.

In order to visualize regional blood flow in various tissues of the mouse at the same time, the distribution of radioactive carbon from 14C-iodoantipyrine was studied by whole-body autoradiography. The mice were frozen with Dry-Ice-hexane at 1, 10, 30 min, and 1 h and 3 h after intravenous injection of 14C-iodoantipyrine. Whole-sagittal sections of the frozen mouse, obtained by using a cryostat microtome, were dried in a cryostat and subjected to autoradiograhy. The resulting dry autoradiographs are called untreated autoradiographs in the present work. The sections were then fixed in cold 6% (w/v) HClO4, dried at room temperature and again subjected to autoradiography. Autoradiographs thus obtained are referred to as treated autoradiographs. It was found that the method could be suitable for the estimation of regional blood flow of the renal cortex, spleen, lung, skeletal muscle, bone marrow, thymus, testes, and brain.