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Biomedical subjects

S Horio

Publications and source records attributed to S Horio.

At least 55 records · Page 3Linked to original sources
PubMed1981

[Plasma steroid hormones in Cushing's syndrome: their relation to cause and clinical manifestations (author's transl)].

For the purpose of studying the relation of diversities of basic lesion as well as clinical manifestation to hormonal abnormality in Cushing's syndrome, 12 kinds of steroid hormones was simultaneously measured in plasma by using 2 types of Sephadex LH-20 column chromatography in a total of 30 patients comprosing 28 cases of Cushing's syndrome and 2 cases of adrenocortical carcinoma which had abnormal plasma steroid hormone levels without sign or symptom of Cushing's syndrome. In the group of Cushing's syndrome were included cases of pituitary ACTH-dependent hyperplasia (Hp.), adrenocortical adenoma(Ad.), bilateral nodular hyperplasia, ectopic ACTH syndrome as well as recurrent Cushing's syndrome following subtotal adrenalectomy. Twelve steroids measured in plasma were pregnenolone(Preg)., 17-OH pregnenolone(17Preg.), progesterone(Prog.), 17-OH progesterone(17Prog.), 11-deoxycorticosterone (DOC), corticosterone(B), aldosterone(Ald.), 11-deoxycortisol(S), cortisol(F), dehydroepiandrosterone(DHA), androstendione(A-dione) and testosterone(T), including precursors (Prec.: Preg., 17-preg., Prog., 17-prog.) as well as hormones belonging to the 3 systems in the biosynthetic pathways of steroid; i.e., glucocorticoids(Glu.C.'s: S,F), mineralocorticoids(Min.C.'s: DOC, B, Ald.) and sex steroids(And.'s: DHA, A-dione, T). In addition, steroidogenesis in isolated adrenal cells obtained surgically from patients with Cushing's syndrome due to Hp. and Ad, was observed. The results were as follows: (1) In cases due to Hp., plasma levels of Glu.C's and And.'s were slightly elevated, while levels of Min.C.'s were within the normal range. On the whole, however, the 3 systems were well balanced. (2) In cases due to Ad., elevated secretion of Glu.C.'s and Min.C.'s was observed, while secretion of And.'s was depressed. Among the 3 fractions of And.'s, depression of DHA and A-dione was characteristic of Ad.. (3) Elevation of And.'s in Hp. and Min.C.'s in Ad. in addition to elevation of Glu.C.'s was in fair correlation with moderate virilism in Hp. and with hypertension and hypokalemia in Ad. respectively. (4) In vitro experiments revealed that Ad. produces not only F but all 12 steroids hormones and that increased DOC and depressed DHA secretion reflected in their plasma levels were the characteristics of Ad. in steroidogenesis. Furthermore, isolated adenoma cells were found to produce Ald. at a higher rate than normal or hyperplasia adrenal cells. This finding may suggest that an intermediate type between Cushing's syndrome and primary hyperaldosteronism can exist in cases of adenoma. (5) In ectopic ACTH syndrome, plasma levels of Glu.C.'s, Min.C.'s and And.'s were equally but more markedly elevated as compared with Hp.. The increase of B was characteristic of this disorder and, coupled with a marked increase of F, seems to be the main cause of hypokalemic alkalosis frequently associated with this syndrome. (6) Nodular hyperplasia was accompanied by elevated Min.C...

Adenoma↗
PubMed1981

Suppression of superprecipitation of contractile proteins from chicken gizzard muscle by preincubation in the presence of adenosine triphosphate without Ca2+.

Superprecipitation of reconstituted actomyosin composed of smooth muscle myosin, skeletal muscle actin and smooth muscle native tropomyosin was studied. When the actomyosin solution was preincubated in the presence of ATP and the absence of Ca2+, or in the relaxed state, superprecipitation was markedly suppressed. The extent of suppression was correlated with the inhibition of the phosphorylation of the 20,000-dalton light chain of smooth muscle myosin. This is consistent with the theory that the interaction of smooth muscle actomyosin is regulated by the phosphorylation of myosin light chain through a system of myosin light chain kinase and phosphatase. However, further studies showed that the myosin light chain kinase and phosphatase system could not explain the present suppression of superprecipitation, even if a cyclic AMP-dependent protein kinase system was also involved. A new regulatory factor should be taken into account in the regulation of smooth muscle actomyosin interaction.

Actins↗