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Biomedical subjects

E Hayashi

Publications and source records attributed to E Hayashi.

At least 199 records · Page 11Linked to original sources
PubMed1976

Accumulation of neutral lipids in Saccharomyces carlsbergensis by myo-inositol deficiency and its mechanism. Reciprocal regulation of yeast acetyl-CoA carboxylase by fructose bisphosphate and citrate.

The abnormal accumulation of lipids due to myo-inositol deficiency in Saccharomyces carlsbergensis, and the mechanism involved was investigated. The deficient cells contained much more neutral lipids with a greater ratio of unsaturated fatty acids compared to the supplemented cells, whereas there was no significant change in their phospholipid contents. The biosynthesis of fatty acids and sterols from acetate, and of triacylglycerols and sterol esters from palmitate was markedly augmented in the deficient cells. Acetyl-CoA carboxylase activity of the deficient supernatant was 2- to 5-fold higher than that of the supplemented. However, the activity from both sources was not significantly different after Sephadex G-25 gel filtration of the supernatant, suggesting the presence of low molecular effector(s) in the deficient supernatant. There was a great increase in acid-soluble glycogen, trehalose, and fructose-1,6-P2, as well as a drastic decrease in citrate in the deficient cells. Their intracellular levels were calculated so that their effects on acetyl-CoA carboxylase was examined over the range of physiological concentration. Citrate strongly inhibited the enzyme activity of the supernatant, but it had no effect on the preparation after gel filtration. On the other hand, fructose-1,6-P2 stimulated the enzyme activity both before and after gel filtration. The acetyl-CoA carboxylase activity in the gel filtrate was measured as a function of citrate concentration at several fixed concentrations of fructose-1,6-P2. Citrate counteracted the activation by fructose-1,6-P2 in a dose-dependent manner. Citrate lacked the inhibitory effect in the absence of fructose-1,6-P2. It was concluded from these results that neutral lipid accumulation in the deficient cells reflected an increase in the synthesis of fatty acids, at least partly based on an enhancement of acetyl-CoA carboxylase activity, and that the operation of a reciprocal regulation of the enzyme by fructose-1,6-P2 and citrate caused a marked elevation of the enzyme activity in the deficient cells with a high fructose-1,6-P2 level and a low citrate level.

Acetyl-CoA Carboxylase↗
PubMed1976

Some factors related to obesity in the Japanese sumo wrestler.

Sumo is an ancient sport in Japan and there are at present over 800 professional sumo wrestlers (rikishis). After entrance into the wrestler society a wrestler takes strenuous daily training together with a very high calorie diet (more than 5,000 cal). Frequency of food intake is twice a day. The average diet of Japanese people contains of 2,279 calories and the meal frequency is generally three times a day. In 96 wrestlers average actual body weight and modified Broca index was 100.4 kg and 143.5%, respectively. In this group the prevalence of overweight with obesity, overweight without obesity, nonoverweight with obesity, and nonoverweight without obesity was 53.4, 39.1, 1.0, and 6.5%, respectively. Also mean serum levels of triglyceride, phospholipid, uric acid, and total protein were significantly higher than those obtained in 89 age-matched healthy males. The incidence of diabetes mellitus, gout, and hypertension in wrestlers was 5.2, 6.3, and 8.3%, respectively, all values being considerably higher than in controls. Weight correlated significantly with skinfold thickness, diastolic blood pressure, total cholesterol, and uric acid in each group. Multiple regression analyses were made treating weight or uric acid as dependent variables in both groups. Obesity, hyperlipidemia, and hyperuricemia in wrestlers were presumed to be caused chiefly by the high calorie diet and partially by the infrequent meal intake.

Adolescent↗
PubMed1976

Fundamental studies on physiological and pharmacological actions of L-ascorbate 2-sulfate. I. On the hypolipidemic effects.

The effects of L-ascorbate 2-sulfate (AAS) on the lipid metabolism were examined in Triton-induced hyperlipemic mice, hypercholesterolemic and normal rats, the following results being obtained. 1) In Triton-induced hyperlipemic mice, AAS (300 mg/kg) significantly decreased the serum cholesterol level, while L-ascorbate (AA, 175 mg/kg) was found ineffective. 2)In hypercholesterolemic rats fed 0.5% cholesterol diet, the consecutive administration of AAS decreased the level of serum cholesterol and liver triacylglycerols. AA only slightly affected these levels. However, both AAS and AA prevented the unordinal increase in the liver weight caused by cholesterol feeding. 3)In normal rats, the administration of AAS over a 4-week period decreased the levels of serum cholesterol and liver triacylglycerols.

Animals↗
PubMed1975

Pharmacological studies on surugatoxin, the toxic principle from Japanese ivory mollusc (Babylonia japonica).

1 Some pharmacological properties of surugatoxin (SGTX), a purified toxic substance from the Japanese ivory mollusc (Babylonia japonica), have been investigated. SGTX (50 nmol/kg i.v.) produced a prolonged fall of blood pressure in anaesthetized cats. This hypotensive effect was neither blocked by atropine and propranolol nor by spinal cord transection. 2 SGTX (37-50 nmol/kg i.v.) inhibited the hypertensive and hypotensive response to 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) and to electrical stimulation of the splanchnic and vagal nerve, whereas it usually augmented the hypertensive response to adrenaline and to 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343) in anaesthetized cats. 3 Close intra-arterial injection of SGTX (6.2-12.3 nmol/kg) to the superior cervical ganglion blocked the contractile response of the nictitating membrane to preganglionic stimulation of cervical sympathetic nerve or injected DMPP, but not to postganglionic stimulation or to injected adrenaline and McN-A-343. 4 SGTX affected neither the indirectly nor the directly stimulated response of the rat isolated phrenic nerve-diaphragm at concentrations less than 12.3 mum. 5 The effect of SGTX on the contractile response to some agonists and on the twitch response to transmural stimulation in the guinea-pig isolated ileum was investigated. At less than 12.3 mumSGTX did not depress responses to acetylcholine or histamine. The curves for nicotine- and DMPP-induced contractions were shifted to the right and depressed gradually as the concentration of SGTX was increased (12.3 nm-1.23 mum). SGTX partially inhibited the contraction induced by 5-hyroxytryptamine and the transmurally-stimulated twitch response. 6 These results suggest that SGTX has a ganglion-blocking action. The mode of anti-nicotinic action of SGTX in the guinea-pig isolated ileum seems to differ from that of hexamethonium and tetraethylammonium and to resemble more closely that of mecamylamine.

Acetylcholinesterase↗