Hormonal regulations of follicle-stimulating hormone receptors in the tests of Japanese quail

The effects of gonadotrophins and testosterone on the binding of 125I-labelled rat FSH to a testicular homogenate of hypophysectomized Japanese quail have been studied. Hypophysectomy resulted in rapid decrease in the binding of FSH per testis but did not change the binding per unit testicular weight, suggesting a decrease in FSH binding per Sertoli cell. Injections of NIH-FSH-S12 to hypophysectomized birds (100 pg/day) for 5 days induced hypertrophy of Sertoli cells and 2·2-fold increase in the binding of FSH per Sertoli cell. Injections of testosterone to hypophysectomized birds (5·0 mg/day) for 5 days also increased the binding of FSH per Sertoli cell 2·3-fold, but did not change the cell size. Combined administration of FSH and testosterone induced 4·4-fold increase in the binding of FSH per Sertoli cell and also marked hypertrophy. The Scatchard plot analysis of the binding of FSH to the testicular preparation of hypophysectomized birds treated simultaneously with FSH and testosterone showed that the number of the binding sites, but not the affinity of the binding, was increased by the hormone treatment. Synergistic action of FSH and testosterone was observed in the increase of not only the number of the FSH binding sites but also in testicular weight and the number of spermatogonia and spermatocytes. These results indicated that FSH receptors in the testes of Japanese quail are regulated by FSH and testosterone. It is suggested that FSH acting synergistically with testosterone increases the sensitivity of the testis to FSH itself by increasing FSH receptors. This self-potentiation mechanism may enable rapid testicular development in photostimulated birds and mammals at puberty.

Enhancement of the antitumor effect of illudin S by including it into liposomes

Entrapping illudin S in liposome markedly enhanced life prolonging effect in ddN mice bearing Ehrlich ascites tumors, presumably by decreasing the side effects.

Partial purification and properties of bovine heart catalase

Catalase was partially purified (about 380-fold purification) from the post-mitochondrial supernatant of bovine heart and compared with catalases from bovine erythrocytes and bovine liver. The electrophoretic mobility in polyacrylamide gel (pH 8.0) of heart catalase was the same as that of erythrocyte catalase and was smaller than that of the liver enzyme. The heart catalase was indistinguishable from erythrocyte catalase in regard to the molecular weights of subunit polypeptides, the inhibition patterns produced by several catalase inhibitors, and specific activity. The pH-activity curve of heart catalase consisted of a characteristic biphasic pattern with a peak at pH 7.5 and a shoulder at pH 10.

Clinical studies of "big ACTH": its physico-chemical characteristics

The big ACTH fractions available from human plasma and pituitary glands and from porcine pituitary glands were physico-chemically characterized by gel filtration, disc electrophoresis and isoelectric separation. In the case of healthy human subjects, big ACTH fractions were isolated by gel filtration from plasma samples taken during states of acute ACTH hypersecretion such as the lysine-8-vasopressin, insulin or metopyrone tests though none of these fractions were isolated from plasma sampled under normal conditions. Even with no stimulation of ACTH secretion, patients with Cushing's disease gave plasma samples that contained an isolable big ACTH fraction, but such a fraction was hardly isolated from plasma taken from patient with Addison's disease. Both human pituitaries and porcine pituitaries contained an isolable big ACTH fraction. By a gel filtration analysis the molecular weight of the big ACTH was estimated to be higher than 20 000. Disc electrophoresis with an acrylamide gel indicated that big ACTH is strongly basic while small ACTH is more acidic than pH 8.3. Isoelectric separation revealed that the isoelectric point of human big ACTH is higher than pH 10.0 while that of small ACTH is about pH 6.8.

Fractionation of aurintricarboxylic acid and effects of its components on nuclear swelling and nucleic acid synthesis

Crude aurintricarboxylic acid synthesized by the conventional method was fractionated into 8 components (A1-A8) by silica gel thin layer chromatography. Some of the components were isolated and their effects were tested on nuclear swelling and on in vitro RNA synthesis and DNA synthesis using isolated polymerases. Only two components with low RF (A7 and A8) induced strong nuclear swelling. The other components were almost inactive. Formaurin-dicarboxylic acid, a contaminating polyanion of crude aurintricarboxylic acid, was synthesized separately. It was as effective as the two active components in nuclear swelling and inhibited RNA and DNA polymerases on naked DNA template. However, it stimulated RNA synthesis on chromatin template probably by dissociating histones from DNA. Unfractionated aurintricarboxylic acid showed the same effects at higher concentrations. A preliminary analysis indicated one of the inactive components (A4) is genuine aurintricarboxylic acid. The results suggest that the observed activity of crude aurintricarboxylic acid is due to some contaminating substances, one of which is formaurindicarboxylic acid.

Role of hydrophobic interaction in hapten-antibody binding

The precipitation reaction of bovine serum albumin coupled with p-azophenylleucine with homologous antibody was inhibited by several structurally related haptens. The isobutyl group substituent on alpha-carbon atom of the leucine residue contributed more than -5.8 Kcal/mol to the free energy of binding. This value was consistent with the free energy change expected from the transfer of n-butane from an aqueous environment to liquid n-butane. The observed contribution was explained, in terms of the hydrophobic interaction of the isobutyl group with the antigen binding site of the antibody molecule. These results were also compared with other hapten-antibody systems.

Mitochondrial sulfhydryl groups. A possible endogenous probe of conformational changes in the mitochondrial membrane

The protein-bound sulfhydryl (SH) groups of the mitochondrial membrane were determined with Ellman's reagent in energized and non-energized configurational states of mitochondria and submitochondrial particles. When beef heart mitochondria were energized by respiration, there was a decrease in titratable protein-bound SH groups which varied according to substrate: NADH-linked substrates induced a decrease of about 10 nmol per mg of protein,succinate about 7, and ascorbate-tetramethyl-p-phenylene-diamine about 3. Similar changes occurred in phosphorylating submitochondrial particles. A decrease in SH titer was also observed in non-energized conditions, induced by hypotonic treatment and by some reagents inhibiting electron transport and oxidative phosphorylation and inducing orthodox configuration. These changes in protein-bound SH groups might be useful in analyzing the conformational states of mitochondrial membranes.

Morphological studies of Gross virus-induced lymphoblasts by scanning electron microscopy

The surface of Gross virus-induced murine lymphoblasts and C-type virus particles budding from these cells were investigated under the scanning electron microscope (SEM). The cells appeared spindle-shaped or roughly-rounded with extensive surface features consisting of microvilli, blebs and ruffled membranes. C-type virus particles were detected on the cell membrane as small spherical particles, distinguishable from the microvilli. Clustered virions were observed in some cases. However, the distribution of virions appeared to be random. The surface of the virion was smooth and had no globular units at high magnification. These morphological observations were confirmed in ultrathin sections.

The presence of phosphate-binding protein in inner mitochondrial membrane

Phosphate-binding protein(s) was found in the inner mitochondrial membrane of calf heart by Sephadex G-200 and G-25 gel filtration. The binding activity was inhibited by N-ethylmaleimide and competed by a large amount of cold phosphate. The amount of phosphate bound to the fraction was 29 nmoles per mg of protein. Affinity chromatography with phosphate-bound Sepharose 4B confirmed the presence of phosphate-binding protein(s) in the active fraction of mitochondrial membrane fractionated by gel filtration.