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Biomedical subjects

Y Kojima

Publications and source records attributed to Y Kojima.

At least 541 records · Page 30Linked to original sources
PubMed1978

Insulin-releasing activity and successful transplantation of pancreatic islets preserved by tissue culture.

Preserving pancreatic islets for 7 days by a making use of the organ culture, we studied the insulin-releasing activity at the time of administration of glucose and various digestive tract hormones for the purpose of clarifying the function of preserved pancreatic islets. Furthermore, we transplanted pancreatic islets preserved for 3 to 5 days into the portal vein of rats with streptozotocin-induced diabetes and reached the following conclusions: (1). The islets of Langerhans of the pancreas responded well to glucose up to the seventh day of preservation and showed patterns similar to those of fresh pancreatic islets with respect to both the dose response and the time response. (2). Preserved pancreatic islets of the pancreas had insulin-releasing activity almost equal to that of fresh pancreatic islets against stimulation by glucagon, tolbutamide, and various digestive tract hormones. (3). Rats with streptozotocin-induced diabetes showed a marked improvement in blood glucose and urine glucose following transplantation of preserved pancreatic islets into the portal vein, and this effectiveness persisted for 6 to 8 weeks.

Animals↗
PubMed1977

[Biochemical studies of acebutolol-the beta1 specificity of acebutolol (author's transl)].

Effects of acebutolol on carbohydrate and lipid metabolism in rats and on adenylate cyclase of heart and liver in dogs were investigated to determine the beta receptor blocking properties of the compound. Acebutolol exhibited the beta blocking activity and inhibited the increase of serum lactate concentration induced by adrenaline. This inhibition was about one-sixth as potent as that of propranolol. In hyperglycemic and free fatty acid effects of adrenaline, acebutolol inhibited the adrenaline-induced free fatty acid increase more effectively than hyperglycemia induced by adrenaline. In the inhibition of stimulated adenylate cyclase activity in the heart and liver, acebutolol was more active on the heart than on liver. Relative beta1 specificity of acebutolol was 93.2. Inhibition of propranolol on adenylate cyclase activity was more potent than that of acebutolol on both tissues, but showed no specificity. These results suggest that acebutolol is beta1 selective, although its beta blocking potency is less than that of propranolol.

Acebutolol↗
PubMed1976

Amino-acid sequence of equine renal metallothionein-1B.

The amino-acid sequence of a metallothionein is reported. Metallothionein is a widely distributed, extremely cysteine-rich, low-molecular-weight protein containing large amounts of cadmium and/or zinc. Metallothionein-1B is one of the two prinicipal variants occurring in equine kidney cortex. The single-chain protein contains 61 amino acids and has the composition Cys20 Ser8Lys7Arg1Ala7Gly5Val3Asp2Asn1-Glu1Gln2Pro2Thr1Met1(Cd + Zn)7. Its amino-terminal residue is N-acetylmethionine. The sequence shows distinct clustering of the twenty cysteinyl residues into seven groups separated by stretches of at least three other residues. Within these groups the cysteines occur seven times in alternating Cys-X-Cys sequences and three times each in Cys-Cys and Cys-X-X-Cys sequences, where X is an amino acid other than cysteine. Another unique feature is the close association of serine and the basic amino acids with cysteine, as manifested by the occurrence of seven Ser-Cys, four Cys-Lys, one Cys-Arg, and three Lys-Cys sequences. These findings are in agreement with the previous suggestion that metallothionein has structurally defined metal-binding sites, most of which contain three cysteinyl residues as the principal metal-binding ligands. The charge difference between the metal-free and the metal-containing protein is consistent with the formation of negatively charged trimercaptide complexes with cadmium and/or zinc ions. The possible additional involvement of serine and the basic amino acids in metal binding is discussed.

Amino Acid Sequence↗