Tryptophan fluorescence of human hemoglobin. II. Effect of inositol hexaphosphate on the T-R transition.

Fluorescence spectra of tryptophan residues of human hemoglobin in the absence and presence of inositol hexaphosphate were measured at room temperature. The tryptophan fluorescence intensity of deoxy HbA was observed to decrease in accordance with the binding with inositol hexaphosphate. The fluorescence intensity of HbA, Hb Kempsey (beta 99 Asp-Asn), Hb Chesapeake (alpha 92 Arg-Leu) and NES-des-Arg Hb (des-141 alpha Arg and beta 93 Cys-N-ethylsuccinimide derivative) in the presence of inositol hexaphosphate exhibits a considerable decrease in the deoxy to oxy transition, while no or slight fluorescence intensity change was observed in the deoxy to oxy transition of Hb Kempsey and NES-des-Arg Hb in the absence of inositol hexaphosphate.

Localization of adenylate cyclase and 5'-nucleotidase activities in human thyroid follicular cells.

The localization of adenylate cyclase and 5'-nucleotidase activities in the follicular cells of adenomatous goiter and normal thyroid was studied by light and electron microscopy. Simultaneous biochemical measurement for both activities was carried out to confirm the histochemical findings. Adenylyl-imidodiphosphate (AMP-PNP) was used as an effective substrate for adenylate cyclase.

[Utilization of minicomputer for the quality control of radioimmunoassay (author's transl)].

In our nuclear medicine laboratory the quality control (QC) of radioimmunoassay (RIA) has been performed along the line of WHO program for standardization and quality control of RIA. The QC procedure was automated using a minicomputer in order to avoid tedious and time-consuming hand processing. The program was written with BASIC language.

Thyrotropin-dependence of the distribution of peroxidase in rat thyroid gland.

After male rats were injected daily with propylthiouracil, whale thyrotropin, or thyroxine for several days, the thyroid glands were examined for their ultrastructural localization of peroxidase. The propylthiouracil treatment caused a marked increase in the number of round, peroxidase-positive vesicles in the apical and middle regions of cytoplasm, and brought about a formation of granular reaction products in the colloid lumen adjacent to the elongated microvilli. Such changes became evident after 2 days of the drug treatment and increased with the time of the effect, until the whole colloid lumen was filled with the reaction products and very elongated microvilli.

Two-state analysis for allosteric properties of abnormal hemoglobins.

To shed light upon the understanding of structure and function relationship of hemoglobin, we determined the oxygen equilibrium curves of a series of alpha 1 beta 2 contact anomalous hemoglobins, low and high spin derivatives of valency hybrid hemoglobins and normal hemoglobin under various conditions comparable with each other using an automatic recording apparatus. The Hill plots of their curves were analyzed by a trial and error method without any assumptions using computer graphic display. The results deduced from these analyses are as follows.

Stopped flow studies on the nonenzymatic reduction of methemoglobin by reduced flavin mononucleotide.

The nonenzymatic reduction of methemoglobin by the reduced form of flavin mononucleotide was studied under various conditions by following the reaction with a stopped flow apparatus. The reaction was very fast, compared with the reduction of the flavin by NADPH-flavin reductase of human erythrocytes, and followed a second order rate law: the rate constant (K) for the reduction of methemoglobin by reduced flavin mononucleotide was determined to be 5.5 X 10(6) M-1 S-1 in 50 mM phosphate buffer (pH 7.

A weak negative inotropic effect of protamine sulfate upon the isolated canine heart muscle.

The direct effect of protamine sulfate upon myocardial inotropism was studied using an isolated canine heart muscle preparation. Isometric force (F) was decreased to 87.6 +/- 1.

Neuromuscular blocking property of minocycline in the rabbit.

The neuromuscular blocking property of minocycline hydrochloride (MNC) was studied in 12 rabbits. In 2 of 6 animals, MNC, 60-160 mg/kg, alone caused a decrease in twitch tension. During partial neuromuscular blockade produced by a continuous infusion of pancuronium, the intravenous administration of MNC, 20--60 mg/kg, resulted in a dose-dependent decrease in twitch tension in 6 animals.

Process of iodination of thyroglobulin and its maturation. II. Properties and distribution of thyroglobulin labeled in vitro or in vivo with radioiodine, 3H-tyrosine, or 3H-galactose in rat thyroid glands.

With the aim of obtaining information on the process of iodination of thyroglobulin, the properties and subcellular distribution of thyroglobulin labeled with radioiodine, 3H-tyrosine, or 3H-galactose were studied. The following results were obtained for 17-19S thyroglobulin isolated from rat thyroid lobes labeled in vitro. (a) The effect of sodium dodecyl sulfate (SDS) concentration (0.

Process of iodination of thyroglobulin and its maturation. I. Properties and distribution of thyroglobulin labeled with radioiodine in pig thyroid slices.

Pig thyroid slices were incubated with Na131I and the 17--19S 131I-labeled thyroglobulin isolated was subjected to dissociation with 0.3 mM sodium dodecyl sulphate SDS) on sucrose density gradient centrifugation and to iodoamino acid analysis. During the incubation, initially dissociable thyroglobulin was gradually altered to 0.

Neuromuscular blocking potency of fazadinium in man.

The study was designed to compare the recovery rates of fazadinium and four other commonly used competitive muscle relaxants in forty patients and eight volunteers. One-fifth to 1/10 of the clinical doses of the muscle relaxants were diluted in 20 ml of saline and injected intravenously at the wrist after inflation of a pneumatic tourniquet on the upper arm. After 3 min the tourniquet was released and the recovery time of twitch tension from 25 to 75% of the control determined.

Mechanism of methemoglobin reduction by ascorbic acid under anaerobic conditions.

The time course of methemoglobin reduction by ascorbic acid under anaerobic conditions was analyzed by using isoelectric focusing on Ampholine plate gel in order to compare results obtained by studies of the changes in absorption during the reaction. The intermediate hemoglobin which appeared all through the reaction was single and identified as the alpha3+beta2+ valency hybrid. In the presence of inositol hexaphosphate, reduction of methemoglobin was considerably accelerated and this acceleration was restricted to the step in which methemoglobin is reduced to the alpha3+beta2+ valency hybrid.