The distribution of some enzymes involved in the steroidogenesis of hen's ovary

Riassunto È stata studiata con metodi istochimici la distribuzione della ⁵-3-idrossisteroide deidrogenasi ( ⁵-3-HSDH) e delle 17-idrossisteroide deidrogenasi (17-HSDH), DPN- e TPN-dipendenti, nell'ovario di gallina ovulante. Mentre la ⁵-3-HSDH è presente in tutti i tessuti a secrezione steroide dell'ovario, la 17-HSDH è localizzata solo nelle cellule della granulosa.     

Ultrastructural localization of vanadium in the blood cells of Ascidiacea.

X-ray histospectrographic analysis at the scanning and transmission electron microscope (STEM) are made on the blood cells of Phallusia mamillata Cuvier and Ciona intestinalis, to study the 'direct' intracellular sites of accumulation of vanadium. The results show a clear accumulation of vanadium on the membrane and in the granules of vacuoles of amebocytes, signet ring cell, compartment cell and traces of metal in the 'vanadophores' of vanadocytes.     

Ultrastructural study of vanadocytes in Ascidia malaca

Summary The ultrastructural aspects of vanadocytes, found in the circulating blood of Ascidia malaca, were studied in formaline-fixed material. The results indicate that the diverse morphological aspects of vanadophores reported here, are probably concerned with different metabolic stages of vanadine.This work was supported by a grant from the University of Naples at the Zoological Station of Naples.     

Ultrastructural localization of vanadium in the blood cells of Ascidiacea

Summary X-ray histospectrographic analysis at the scanning and transmission electron microscope (STEM) are made on the blood cells ofPhallusia mamillata Cuvier andCiona intestinalis, to study the direct intracellular sites of accumulation of vanadium. The results show a clear accumulation of vanadium on the membrane and in the granules of vacuoles of amebocytes, signet ring cell, compartment cell and traces of metal in the vanadophores of vanadocytes.We thank Dr C. Weichan and Mr G. Hubert for kind hospitality and for technical assistance in the Department of Electron Microscopy of Siemens Laboratory in Karlsruhe (BRD). We thank also Dr V. Andria of Siemens Elettra in Rome (Italy).     

Arginine-vasotocin and gonadal activity in the lizard,Podarcis s. sicula Raf.

Summary Arginine-vasotocine (AVT) injected into male adult lizards,Podarcis s. sicula Raf., inhibits the last phases of spermatogenesis and the endocrine activity of gonads. In female lizards the substance induces an early interruption of egg deposition.