Effects of metaraminol on the secretion of fluid and glycoproteins from the rat submandibular gland

The actions of metaraminol on the secretion of fluid and glycoproteins from rat submandibular glands were investigated using phentolamine, propranolol and reserpine. Metaraminol at doses from 1 to 8 mg/kg (i.p.) increased the salivation and the amounts of protein in submandibular saliva in a dose-dependent manner. The salivation induced by metaraminol at 2 mg/kg was inhibited strongly by pretreatment with propranolol, whereas the salivation induced by metaraminol at 8 mg/kg was inhibited strongly by phentolamine. Reserpine inhibited the secretion of fluid caused by both doses of metaraminol. The electrophoretic profiles of saliva evoked by metaraminol at 2 mg/kg revealed two main bands of glycoprotein, I and IV, which originated from the acinus, and the intensities of these bands were decreased by treatment with propranolol, whereas the major band in saliva induced by 8 mg/kg of metaraminol was glycoprotein III, which originated from the granular tubules. The intensity of band III was decreased by pretreatment with phentolamine. These results suggest that metaraminol, at small doses, stimulates mainly the beta-adrenoceptor in the acinus, whereas at large doses, it prominently stimulates the alpha-adrenoceptors in the granular tubules, although metaraminol at small and large doses is able to stimulate alpha- and beta-adrenoceptors in rat submandibular gland.     

抗人生长激素免疫血清的制备和鉴定

Using small dosage of human growth hormone to immunize rabbit or guinea pig, it is able to induce anti-hGH antibody formation with high titre and high affinity that could be applied to hGH RIA. In the present study five rabbits and three guinea pigs were immunized with 125-200 micrograms and 250-285 micrograms per animal of hGH respectively, followed by boosters of 10-20 or 160-250 micrograms of hGH at 2-4 week intervals for 6 or 3 months. Blood was drown 1-2 weeks before each booster for determination of antibody formation. Antibody titre and affinity were successively observed and specificity of antibody was determined for the final bleeding. It was shown that titres of immune sera from guinea pigs were much higher than those of rabbit immune sera, but vice versa for antibody affinity. This might be due to larger immunogen dose used for guinea pigs than for rabbits. Fourteen different peptide hormones were tested in reference to cross-immunoreactivity to anti-hGH antibody. It could be demonstrated that the major cross-reactive hormones are hFSH and hLH, and hTSH also reacts to rabbit anti-hGH immune sera at a lesser degree. These cross reactivities are obviously owing to the molecular homogeneities between hGH and these hormones especially of their alpha-subunits.     

Effects of insulin on maltase and N-acetyl-beta-D-glucosaminidase (NAG) activities of serum and kidney in experimental diabetic rats

The activities of lysosomal maltase in the serum, urine and kidney were determined in rats with diabetes induced by streptozotocin (STZ, 75 mg/kg, i.p.) and compared with the changes in N-acetyl-beta-D-glucosaminidase (NAG) activity. Moreover, effects of insulin on maltase and NAG activities of the serum, urine and kidney in diabetic rats were studied. The following results were obtained: 1) The serum maltase activity within 24 hr after administration of STZ was influenced by insulin secretion. 2) Significant increases in blood urea nitrogen (BUN) levels were observed from the 3rd week after a single administration of STZ. The serum insulin level significantly decreased at 3 weeks after treatment of STZ. In this time, maltase activity in the serum rapidly increased, while the enzyme activity in the kidney decreased considerably. On the other hand, the changes in NAG activities in the serum, urine and kidney after administering STZ were almost similar to those in maltase activities. 3) There were positive relationships between maltase and NAG activities in the serum and urine in diabetic rats, respectively. 4) When lente insulin (2U) was subcutaneously injected once daily for 20 days from 24 hr after administration of STZ, NAG activities in the serum and kidney approached to the control levels. However, maltase activities in the group treated with insulin were significantly higher in the serum and kidney than those in the control group.     

Electrophysiological actions of N-(2,6-dimethylphenyl)-8-pyrrolizidine-acetamide hydrochloride hemihydrate (SUN 1165), a new antiarrhythmic agent

The electrophysiological actions of SUN 1165 on isolated guinea pig atrial and papillary muscles, canine Purkinje fibers, and rabbit sinoatrial node were studied using standard microelectrode techniques. SUN 1165 in low (10(-7) g/ml) concentration had little effect on any of the action potential parameters measured. Intermediate (10(-6) g/ml) concentration of the compound shortened the duration of action potential of canine Purkinje fibers and increased ratio of the effective refractory period to the duration of action potential at 90% repolarization in guinea pig atrial muscles. At high (10(-5) g/ml) concentration, the compound reduced the maximum rate of rise of phase 0 in guinea pig atrial, papillary muscles, and canine Purkinje fibers, though the change in the latter was not statistically significant, and also decreased the action potential amplitude in guinea pig atrial muscles and canine Purkinje fibers. At all concentrations (10(-7)-10(-5) g/ml) tested, the compound exerted little effect both on spontaneous action potentials in rabbit sinoatrial node cells and on Ca2+-mediated slow responses in partially depolarized guinea pig papillary muscles. These results indicate that SUN 1165 may selectively inhibit cardiac sodium channels and is likely to be of value in correcting not only ventricular but also supraventricular tachyarrhythmias.     

Myrocin C, a new diterpene antitumor antibiotic from Myrothecium verrucaria. I. Taxonomy of the producing strain, fermentation, isolation and biological properties

A new diterpene antitumor antibiotic, myrocin C, has been isolated from the culture filtrate of a soil fungus, Myrothecium verrucaria strain No. 55. The antibiotic was effective against Gram-positive bacteria, fungi and yeasts, and prolonged the life span of mice bearing Ehrlich ascites carcinoma.     

Liver transplantation in children. Blood transfusion and metabolic disorders

Metabolic disorders during hepatic transplantation can be partly induced by blood transfusion. A retrospective survey of perioperative biological data recorded in patients under 18 years of age having liver transplantation was performed. Blood transfusion was also studied. For this evaluation, patients were divided in a paediatric group I (n = 20; mean age: 3.7 years) and an adolescent group II (n = 11; mean age: 14.3 years). Blood transfusion was significantly (p less than 0.05) more important in group I (302 +/- 286 ml X kg-1) than in group II (148.5 +/- 156 ml X kg-1). Autotransfusion of washed red cells was performed in six patients, allowing a mean 17 +/- 7% saving in blood transfusion. Severe hypernatraemia over 152 mmol X l-1 due to blood transfusion was observed only in five patients in group I. Hyperglycaemia increasing till the revascularization of the new liver was constant in both groups, but significantly more pronounced in group II. Cardiac arrest occurred twice in group I at initial revascularization. In group I, children with biliary atresia were not significantly different from the others for the duration of operation and the volume of blood transfusion; however the latter was more abundant. Conversely, in group II, the duration of operation was longer (p less than 0.05) in patients with previous abdominal surgery than in others. Finally the paediatric group differs from the adolescent group by obvious differences in anaesthesia and intensive care and specifically in hepatic transplantation by larger volume of blood transfusion leading to severe hypernatraemia. In further studies, adolescents should be distinct from the paediatric group and included in the adult group.     

Antitumor activity of orally administered streptococcal preparation, OK-432 on murine solid tumors and its absorption from the gut

OK-432 is an immunopotentiator which is normally administered by injection. In the present study, the antitumor activity of orally administered OK-432 on various solid tumors and the absorption of OK-432 from the gut were studied. Orally administered OK-432 inhibited the growth of Meth-A and BAMC-1 fibrosarcomas which had been subcutaneously transplanted in BALB/c mice. Autoradiograms of mice which had been administered 14C-labelled OK-432 orally demonstrated the absorption of OK-432 from the gut, and about 6% of orally administered OK-432 was absorbed 24 hrs after its administration. Moreover, an immunofluorescent study using an anti-OK-432 antibody revealed specific fluorescence in the mesenteric lymph node of mice which had been orally administered with OK-432. These results suggest that oral administration of OK-432 may be a beneficial immunotherapy.