Mitsuo Hata

The potent activity of fresh water fish kidney cells in cell-killing I. Characterization and species-distribution of cytotoxicity

Abstract Kidney cells of fresh water fishes, Cyprinus carpio (carp), Carassius cuvieri (crucian carp), Ctenopharyngodon idella (grass carp), Misgrunus anguillicandatus (orienta) weather fish) and Channa argus (northern snakehead) were markedly cytotoxic against certain established mammalian cell lines when incubated at 25°C in the absence of specific antibody. Cytotoxicity occurred immediately after incubation with targets, increased exponentially and was accomplished within 6 hrs. The cytotoxicity was mediated by the intact cells but not by either their extracts or culture supernatants. The cytotoxic activity was directed against established cell lines but not normal resting cells. Under similar conditions, kidney cells of salt water fishes showed no cytotoxicity against any targets tested. Leukocytes obtained from various lymphoid organs of other normal higher vertebrates also showed no such potent cytotoxicity. These results indicate that a population(s) of kidney cells in fresh water fishes of stenohaline type carrys the killing activity with a spectrum of target cells similar to that of activated macrophages or natural killer cells in mammals.

Carotenoid metabolism in Artemia salina L.

Abstract 1. 1. The carotenoid metabolism in Artemia salina has been studied with the feeding of algae Chaetoceras gracilis and pure carotenoids. 2. 2. Artemia salina was unable to metabolize β-carotene to astaxanthin beyond canthaxanthin. 3. 3. The major carotenoid of Artemia salina fed Chaetoceras gracilis , β-carotene, echinenone and canthaxanthin was canthaxanthin. Astaxanthin was not found in all groups. 4. 4. Light did not affect the quantity of total carotenoids, but accelerated the accumulation of canthaxanthin.

Carotenoid pigments in goldfish (Carassius auratus L.)-VI. The effect of ACTH and phenylthiourea on the discoloration and the carotenoid metabolism

Abstract 1. 1. Injection of ACTH resulted in blacking of the integument but it did not inhibit discoloration. ACTH had no effect on the carotenoid metabolism. 2. 2. Phenylthiourea treatment resulted in making the integument paler, finally to a yellowish light grey, but it did not inhibit discoloration. 3. 3. Phenylthiourea strongly affected the metabolism of ketocarotenoids. The metabolic pathway, monoketocarotenoid to diketocarotenoid, was inhibited. The accumulation of carotenoid was also inhibited. 4. 4. From the above-mentioned results, it seems that the thyroid has no direct relation to discoloration and inhibition of ketonization of xanthophylls.

Isolation and properties of peridinin-chlorophyll-α-protein complex from the brick-red-colored oyster, Crassostrea gigas

Abstract 1. 1. Two peridinin-chlorophyll-α-proteins (PCP), F I and F II, were isolated from brick-red-colored oysters. 2. 2. The PCPs showed similar spectral properties (visible and CD), a single broad band in disc gel electrophoresis, chromophore composition (peridinin:chlorophyll. a = 4:1 in molar ratio) and multiple pI forms. 3. 3. The F I is dimer of the F II. 4. 4. The molecular weight of the F II was 39,000 by gel filtration and 36,800 ( 18,400 × 2 ) by SDS electrophoresis.