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.     

Bleeding tendency as a first symptom in children with congenital biliary dilatation.

AIM OF THE STUDY: Although a bleeding tendency as a first symptom is a critical condition in congenital biliary dilatation (CBD), the clinical details of this symptom remain unclear. We assessed this condition in children with CBD in this paper. MATERIALS AND METHODS: Sixty-five children with CBD were treated at our institute between 1983 and 2004. The children, initially presenting with bleeding manifestations such as intracranial hemorrhage and bloody stools, were defined as the bleeding group, and the remaining children with digestive symptoms such as abdominal pain and vomiting were defined as the digestive group. The clinical features were compared between these two groups. RESULTS: In 6 of the 65 cases, bleeding manifestations were noted (9.2 %). All six had cystic-type choledochal dilatation. The mean age of the bleeding group was significantly younger than that of the digestive group, and bleeding was more frequent, especially in infants less than 12 months of age. In a laboratory study, the bleeding group showed a more prolonged blood coagulation time than the digestive group did. Serum amylase and lipase levels in the bleeding group were almost normal, while those in the digestive group were significantly higher. The direct bilirubin level in the bleeding group was significantly higher than that in the digestive group. CONCLUSIONS: Disturbed blood coagulation due to vitamin K deficiency related to cholestasis results in a bleeding tendency in children with CBD. Therefore, pediatric surgeons should be aware of this rare but critical condition which can be prevented by rapid and precise treatment with vitamin K supplementation.