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Biomedical subjects

S Morimoto

Publications and source records attributed to S Morimoto.

At least 865 records · Page 48Linked to original sources

[Pharmacological study on diuretic action of 2-methyl-3-(o-tolyl)-6-sulfamyl-7-chloro-1, 2, 3, 4-tetrahydro-4-quinazolinone (metolazone) (author's transl)].

Renal effects of metolazone (MET), a new diuretic agent, were compared with those of hydrochlorothiazide (HCT) in rats. MET in an oral dose of 0.01 approximately 0.5 mg/kg resulted in a dose-related increase in urine flow, sodium excretion and osmolal clearance in male rats. The natriuretic action of MET was not enhanced by administration of an increased dosage (1 approximately 5 mg/kg). Urinary excretion of potassium was significantly increased after MET, but was less than that of sodium. Therefore, the ratio of urinary concentration of sodium to potassium was markedly increased. Similar results were obtained when MET was intraperitoneally administered. In female rats, MET also proved to be an effective natriuretic. The diuretic effects of HCT were qualitatively similar to those of MET, but MET was 10--20 times as potent as HCT on a basis of minimal effective dose. In the renal clearance experiments, MET did not influence the renal plasma flow and glomerular filtration rate. From these findings, it is concluded that MET exerts a diuretic effect by inhibiting the reabsorption of electrolytes in the renal tubules.

Administration, Oral↗

Re-evaluation of exercise as a screening test for ruling out human growth hormone deficiency.

Human growth hormone (HGH) response to exercise was studied in 27 normal children and 152 children with a chief complaint of short stature and in 9 patients with HGH deficiency. Of the 152 children 107 could be ruled out of HGH deficiency since HGH level increased to more than 5 ng/ml during exercise, and of the remaining 45 children of non-responders to exercise, 22 were ruled out of HGH deficiency since bone age to chronological age ratio was more than 0.9 and/or height increment for the past 3 years was more than 15 cm. Seventeen patients were hospitalized for further examinations, which resulted in finding normal HGH secretion in response to insulin-induced hypoglycemia, arginine infusion and/or propranolol-glucagon test in 12 children and also in finding no HGH deficiency in children higher than -2.0 S.D., but 5 HGH-deficient children in those lower than -2.0 S.D. Exercise can be used as a screening test for ruling out HGH deficiency when HGH secretion in response to exericse is evaluated by height, bone age and height increment of the patients.

Adolescent↗

Radioimmunoassay of human calcitonin using labeled [Asu1, 7]-human calcitonin analogue.

Application of synthetic human calcitonin analogue ([Asul,7]-hCT) was attempted, since it is chemically more stable than native hCT. [Asu1, 7]-hCT was successfully labeled with 125I to a specific activity ranging from 410 to 540 microCi/microgram. Sensitivity, recovery and reproducibility of the assay system using 125I-labeled [Asu1,7]-hCT analogue, standard synthetic hCT and its antibodies, were 49 pg/ml, 99.8 +/- 4%, and 7.95% (C. V. within assay) or 21.9% (C. V. between assays), respectively. The dilution curve of the sera obtained from patients with medullary carcinoma paralled well with the standard curve. 125-I-labeled [Asu1, 7]-hCT analogue can be used for routine radioimmunoassay of hCT.

Animals↗

Prolactin and TSH responses to TRH, chlorpromazine and L-dopa in children with human growth hormone deficiency.

Prolactin (PRL) and TSH responses to TRH, chlorpromazine (CPZ) and L-DOPA were studied in 23 children (15 male and 8 female) with human growth hormone (HGH) deficiency. Eight patients (group I) showed normal PRL response to TRH and CPZ but TSH response to TRH was delayed in 4 of this group. Twelve patients (group II) had normal (4 patients) or higher (8 patients) baseline PRL level and showed lower PRL response to CPZ than that to TRH. TSH response to TRH was normal in 3, blunted in 1, and delayed in 8 patients. Three patients (group III) had no PRL response to either TRH or CPZ. TSH response to TRH was normal in 1 but blunted in 2 patients. Of 8 patients with a higher baseline PRL level (group II and III), L-DOPA suppressed PRL secretion to less than 50% of the initial value in 7 patients, but not in 1 patient, in whom the diagnosis of hypothalamic tumour was established on brain surgery following these examinations. These results suggest that hypothalamic disorders are involved in more than half of 23 children with HGH deficiency.

Adolescent↗

The polymerization of alpha-aminopropionitrile.

The mixture of alpha-aminopropionitrile and alpha, alpha'-iminodipropionitrile polymerized to solidify almost at the temperature near 0 degrees C during 8 years. The conversions based on decreasing of those reactants were 61 and 98% at 4 and 8 years, respectively. The fractionation of 4 and 8 years product using Sephadex G 10 yielded their predominant amounts in the oligomer and polymer section, respectively. The oligomer section product of 8 years product was analyzed by means of ion exchange chromatography and its trimethylsilyl derivative was also analyzed by means of gas chromatography combined with mass spectrometry. These results identified dialanine and trialanine and their amides and nitriles.

Aminopropionitrile↗

The synthesis and chromatography of peptine nitriles.

Di- and tripeptide nitriles, glycylaminoacetonitrile (Gly-AAN), diglycylaminoacetonitrile (Gly-Gly-AAN), alany-alpha-aminopropionitrile (Ala-APN), and dialanyl-alpha-aminopropionitrile (Ala-Ala-APN) were synthesized first. These peptide nitriles and related peptides and peptide amides were analyzed by means of ion-exchange chromatography. The every two diastereomers of dialanine, dialanine amide, and Ala-APN were separated into two peaks by using a pH 3.25 buffer as an eluent. The four isomers of trialanine, trialanine amide, and Ala--Ala APN gave four, two, and one peak, respectively under the same conditions. The trimethylsilyl derivatives of alanyl peptides and related compounds were analyzed by means of gas chromatogrpahy combined with mass-spectrometry. The parent (M+ and/or M+-15) and other mass numbers observed in their mass-spectra supported the introduction of various numbers of trimethylsilyl groups.

Chromatography, Gas↗

The asymmetric adsorption of alpha-aminopropionitrile on D-quartz.

alpha-Aminopropionitrile was adsorbed on the powdered D-quartz, recovered as N-trifluoro-acetylalanyl-(+)-secondarybutyl ester, and analyzed by means of gas chromatography. The asymmetric result supporting the preferential adsorption of L-antipode was obtained and its significance in chemical evolution has been discussed.

Adsorption↗

Occurrence of renovascular hypertension in two sisters.

Renovascular hypertension in two sisters, aged 22 and 20, respectively, has been described. Renal artery stenoses were observed unilaterally in the elder patient and bilaterally in the younger one. In both patients, the functional significance of unilateral stenosis of the renal artery was documented by the renal vein renin ratio between the affected side and the contralateral or less affected side. High blood pressure and elevated plasma renin activity have been normalized with a unilateral revascularization in the elder patient, and with the treatment of propranolol in the younger one. The histological examination of the stenotic renal artery in the elder patient showed a finding comparable to the perimedial fibroplasia in Harrison and McCormack's classification of idiopathic fibromuscular stenosis.

Adult↗

Effect of a spironolactone derivative (SC 14266) on Plasma renin activity in adrenal regeneration hypertension.

The effects of treatment with a spironolactone derivative (SC 14266) for 9 experimental weeks on blood pressure and plasma renin activity (PRA) were investigated in unilaterally nephroadrenalectomized rats drinking 1% saline ("unilater nephrectomy"), unilaterally nephroadrenalectomized and contralaterally adrenal-enucleated rats drinking 1% saline ("adrenal enucleation") and intact rats drinking tap water ("normal"). The development of hypertension in "adrenal enucleation" rats was prevented by treatment with SC 14266 and the drug did not significantly affect the blood pressure in either "unilateral nephrectomy" or "normal" rats. SC 14266 did not influence a low level of basal PRA and the blunted response of PRA to furosemide administration in either "unilateral nephrectomy" or "adrenal enucleation" rats. On the other hand, PRA after furosemide administration in "normal" rats receiving SC 14266 was significantly higher than that in those rats treated with vehicle. The results suggest that the mineralocorticoid(s) secreted by the enucleated adrenal has a hypertensogenic property but no effect on the suppression of renin secretion under a high sodium intake and the unilateral nephrectomy.

Adrenal Glands↗

Changes in plasma renin activity and plasma aldosterone in the induced paralytic attack of thyrotroxic periodic paralysis.

Changes in serum electrolytes, haematocrit, plasma renin activity and plasma aldosterone induced by glucose and insulin (GI) infusion were serially investigated in seven patients with periodic thyrotoxic paralysis. An attack which developed into complete quadriplegia was induced within 90 min after the beginning of the GI infusion in four out of seven patients. Only a slight paralysis of the legs was produced in another two patients and induction of an attack did not materialize in one. In four patients with complete quadriplegia, the mean values of serum sodium and potassium concentrations, haematocrit, plasma renin activity and plasma aldosterone slightly decreased immediately after the beginning of the GI infusion. Induction of a paralytic attack was not accompanied by any significant changes in serum sodium concentration, haematocrit, plasma renin activity and plasma aldosterone either 15 min before or after the onset of attack, while the serum potassium concentration progressively decreased, and an increase in plasma aldosterone associated with an increase of haematocrit and plasma renin activity reached a peak level at the stage of complete quadriplegia. On the other hand, in the three patients in whom an infusion produced slight or no paralysis of the legs, changes in the serum sodium concentration, haematocrit, plasma renin activity and plasma aldosterone were insignificant and the serum potassium concentration was slightly but insignificantly decreased. These results suggest that hyperaldosteronism may not be a trigger for the induced paralytic attack but a phenomenon secondary to volume depletion and a change in potassium homoeostasis induced by GI infusion.

Adult↗