Separation of Bombyxin from a neuropeptide of Bombyx mori showing Summer-morph-producing Hormone (SMPH) activity in the Asian Comma Butterfly,Polygonia c-aureum L

A neuropeptide from brain-suboesophageal ganglion (Br-SG) complexes of the silkmoth, Bombyx mori, shows summer-morph-producing hormone (SMPH) activity in the Asian comma butterfly, P. c-aureum. The SMPH-active peptide was extracted and demonstrated to be almost the same molecular size as bombyxin (4-5kD), a nueropeptide which shows prothoracicotropic hormone (PTTH) activity when assayed in vitro with prothoracic glands (PGs) of 4th-instar B. mori larvae in vitro. A Sephadex G-50 fraction of 3-8kD molecules prepared from Br-SG complexes of B. mori adults was applied to CM-, SP-, DEAE- or QAE- Toyoperal columns at pH 5.6 (or pH 6.9). The SMPH-activity could be separated from the PTTH-activity (or bombyxin) by subjecting a SMPH- and PTTH-active preparation of B. mori to anion-exchange chromatography at pH 6.9. By reversed-phase HPLC following an anion-exchange chromatography, SMPH-activity was recovered in two fractions of 40-45% acetonitril. Results demonstrate that the B. mori peptide showing the SMPH-activity in P. c-aureum is a different molecule than bombyxin.     

Teratogenic effects of avidin-induced biotin deficiency in mice

Teratogenic effects of maternal biotin deficiency were examined at different levels of severity by adding three levels of avidin (10, 20, or 40 mg/kg) in the basal diet. There was a considerable increase of fetuses with multiple congenital malformations (micrognathia, cleft palate, and micromelia) with increasing amounts of avidin. The dose-response relationship was observable in the incidence of each malformation as well. The body weight of live fetuses was also significantly reduced. However, the dams did not exhibit any typical signs of biotin deficiency, such as loss of hair, dermatitis, or nervous irritability. These results suggest that biotin is important for early embryonic development in the mouse.     

Depside as potent inhibitor of prostaglandin biosynthesis: a new active site model for fatty acid cyclooxygenase

Forty depsides and depsidones, the esters of phenolcarboxylic acids, were examined for their inhibitory effect against prostaglandin biosynthesis with rabbit renal microsomes. 4-0-Methylcryptochlorophaeic acid was the most active inhibitor so far tested and its IC50 value was 0.34 muM. Kinetic investigation has shown that this depside acts competitively with respect to arachidonic acid as most of the non - steroidal antiinflammatory drugs. X-Ray analysis has revealed that 4-0-methylcryptochlorophaeic acid maintains its rigid conformation by forming a strong hydrogen bond between the hydroxyl and methoxyl groups. Comparison of CPK models between 4-0-methylcryptochlorophaeic acid and non-steroidal antiinflammatory drugs revealed that the carboxyl group and the two rings of these drugs are almost superimposable to those of the depside. This finding led us to propose a new active site model based on the three dimentional structure of the depside.     

Photochemical reaction of 9-cis-retro-γ-rhodopsin at low temperatures

9-cis-Retro-γ;rhodopsin (λ_max = 420 nm) was prepared from 9-cis-retro-γ-retinal and cattle opsin. After cooling to liquid nitrogen temperature (77 K), the pigment was irradiated with light at 380 nm. The spectrum shifted to the longer wavelengths, owing to formation of a batho product. This fact indicates that the conjugated double bond system from C-5 to C-8 of the chromophoric retinal in rhodopsin was not necessary for formation of bathorhodopsin. Reirradiation of the batho product with light at wavelengths longer than 520 nm yielded a mixture composed of presumably 9- or 11-cis forms of retro-γ-rhodopsin. These three isomers are interconvertible by light at liquid nitrogen temperature. Thus the retro-γ-rhodopsin system is similar in photochemical reaction at 77 K to cattle rhodopsin system. Each system has its own batho product. Based on these results, it was infered that the formation of bathorhodopsin is due to photoisomerization of the chromophoric retinal of rhodopsin and is not due to translocation of a proton on the ring or on the side chain from C-6 to C-8 of the chromophoric retinal to the Schiff-base nitrogen.     

Screening method for prolidase deficiency

Summary A simple procedure was developed to determine prolidase activity in dried blood specimens. One thousand dried blood specimens from newborns were examined by this new method. Prolidase activities ranged from 140 to 370 nmol per 3 mm disc per hour (233±43, mean ± SD), and less than 2% of the samples overlapped the heterozygote values. This method should be useful in the mass screening for prolidase deficiency.This research was supported by a Research Grant from the Ministry of Education Japan 1979     

Radioimmunoassay for β-endorphin: Presence of immunoreactive “big-big” β-endorphin (“big” β-lipotropin) in human and rat pituitaries

A sensitive and specific radioimmunoassay for β-endorphin has been developed with an antiserum obtained in a rabbit immunized with β-endorphin contained in crude porcineACTH preparations. The minimal detectable quantity was 5 pg. The antiserum used reacted slightly with ovine β-lipotropin (5.5 %), but showed negligible cross-reactivity with other fragments of β-lipotropin, α-MSH and ACTH. Using this radioimmunoassay we have observed the presence of “big-big” β-endorphin (“big” β-lipotropin) with apparent molecular weights of 37,000 and 31,000 in human and rat pituitaries respectively, in addition to β-lipotropin and β-endorphin, by Sephadex gel-chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis.     

Effect of furosemide on urinary excretion of prostaglandin E in normal volunteers and pateints with essential hypertension

Urinary excretion of prostaglandin E was measured radioimmunologically in 19 healthy persons ( 15 men and 4 women ) and in 16 patients ( 10 men and 6 women ) with essential hypertension before and after the administration of furosemide. The excretion rates were increased from 26.3±3.0 to 64.5±11.3 ng/hr in the former and from 11.9±2.7 to 26.9±85 ng/hr in the latter. There was a significant difference between them, healthy subjects showing a greater increase than patients with essential hypertension.There was an obvious sexual difference in urinary excretion of prostaglandin. In men, greater increase in the excretion rates was found than in the women. Greater increases were also obtained in healthy men than in hypertensive men and in healthy women than in hypertensive women. The present results suggest that furosemide enhances urinary excretion of prostaglandin E by mechanisms which entails either an increase in prostaglandin synthesis or a decrease in renal metabolism.