Dopamine-β-hydroxylase,adrenaline, noradrenaline and dopamine in the venous blood of adrenal gland of man: A comparison with levels in the periphery of the circulation

Summary In 10 human subjects plasma dopamine--hydroxylase activity was found in the adrenal vein blood to be as high as in the periphery of the circulation. Adrenaline concentration in the adrenal vein blood was in the mean 170 times, noradrenaline concentration 11 times and dopamine concentration little higher than levels in the periphery.This study was supported by the Deutsche Forschungsgemeinschaft.     

Nuclear pores in the spermatozoon of the rat

Summary The paper describes a hexagonal array of nuclear pores in a non-redundant region of the nuclear envelope underlying the basal surface of the rat spermatozoon head. It is concluded that intranuclear material protruding through these pores is the cause of the characteristic rows of circular bumps found in surface replicas of this region.     

Serum enzyme activities in the African elephant (Loxodonta africana)

Summary The serum activities of aspartate aminotransferase, alanine aminotransferase, -hydroxybutyrate dehydrogenase and creatine phosphokinase have been measured in the African elephant. In general, the values were broadly comparable with those of man except that alanine aminotransferase was much lower and creatine phosphokinase higher. No variation due to age, sex, season or location was observed.     

Structural changes of deoxyribonucleoprotein fibres following gamma-irradiation under aerobic and hypoxic conditions.

The DNP fibres gamma-irradiated under aerobic condition showed a reduction of their diameter, while no remarkable changes were observed in the DNP fibres irradiated under hypoxic condition by scanning electron microscopy.     

The loss of biological activity of 5-hydroxytryptamine creatinine sulphate.

5-Hydroxytryptamine creatinine sulphate loses its biological activity when maintained at room temperature. The loss of 5-HT activity (in stimulating sodium transport across frog skin) is greater than the loss of creatinine sulphate activity (inhibition of sodium transport).     

Effect of X-537A on the phosphorylated protein in sarcoplasmic reticulum vesicles

Summary The effect of the antibiotic X-537A on the phosphorylated ATPase (EP) was investigated. The results show that X-537A depresses the level of EP which is dependent on the Ca²⁺ gradient, while the Ca²⁺-independent EP is not affected. Acknowledgments. This work was supported by grants from the Instituto de Alta Cultura of the Portuguese Ministry of Education (No. CB/2) and the Calouste Gulbenkian Foundation.     

Regulation of enzymes of ethanol metabolism in yeast (Rhodotorula gracilis)

Summary The three enzymes of ethanol metabolism alcohol dehydrogenase, aldehyde dehydrogenase and acetyl-CoA synthetase in the obligate aerobic yeastRhodotorula gracilis are repressed by glucose and induced by C₂ metabolic fuels with a regulatory pattern indicating a correlation in the control mechanisms. To try an identification of the molecular signals involved in the transmission of the inducing stimulus, experiments were carried out by blocking with 2 mM pyrazole the ethanol acetaldehyde metabolic step. Results indicate that ethanol is not specifically required as a molecular signal for induction.This work was supported by a grant from the Italian Consiglio Nazionale delle Ricerche.