The structure of the ovary and oogenesis in the earthworm, Dendrobaena veneta (Annelida, Clitellata)

The structure of the ovary and the type of oogenesis were determined in the earthworm Dendrobaena veneta (Oligochaeta, Haplotaxida, Lumbricidae) with histological, electron-microscopic and immunocytochemical methods. In this species the ovary is of the alimentary, nutrimentary type because it contains oocytes and the nurse cells (trophocytes). The ovarian stroma is built by somatic cells, the processes of which are connected to each other via numerous desmosomes. The somatic cells and their processes envelop the germ cells tightly and play a supportive role. Oogonia, oocytes and trophocytes are arranged in distinct zones in the ovary. Trophocytes form chains of cells, which are interconnected by intercellular bridges. Numerous microtubules are located within the latter. The oocytes are distally arranged in the ovary. Vitellogenesis involves both auto- and heterosyntheses. The results obtained were compared with the reports on oogenesis in other representatives of Annelida.

Effect of chlorfenvinphos on rat liver subjected to ischemia and reperfusion

The study was performed on rats divided into 9 groups. Groups 1-3 served as controls. In groups 4 and 5 rat livers were subjected to 90-min ischemia followed by 12- or 24-hour reperfusion. In groups 6 and 7 rats were injected with intraperitoneal chlorfenvinphos (2 mg/kg b.w.) and sacrificed after 12 or 24 hours. In groups 8 and 9 rat livers were subjected to 90-min ischemia, 12- or 24-hour reperfusion and then rats were injected with chlorfenvinphos (2 mg/kg b.w.). Liver sections were evaluated morphologically, histochemically (SDH, LDH, G6Pase, glycogen, Mg2+ ATPase and AcP). The microsomal fraction of the liver was evaluated for cytochrome P450 content and NADPH-cytochrome P-450 reductase activity. It has been found that liver ischemia and reperfusion result in extensive necrosis, enzymatic disturbances, particularly in acinar zone 3. Ischemia as well as reperfusion decrease the cytochrome P450 content of hepatocytic microsomes and the activity of NADPH-cytochrome P-450 reductase. Intraperitoneal injection of chlorfenvinphos during ischemia and reperfusion dramatically intensifies damage to the liver, although chlorfenvinphos alone produces only mild nonspecific effects on the morphological and enzymatic structure of the liver.

Effect of ethanol and diazepam given to pregnant rats on the behavior and catecholamine content in the brain of offspring

Effect of separate and combined treatment with ethanol and diazepam applied to pregnant rats upon the behavior of 3- and 6-week old and 3 month old rats, as well as on the content of noradrenaline (NA), 5-hydroxytryptamine (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) in various brain areas was investigated. It has been shown that separate application of ethanol and diazepam causes slight changes in the behavior and content of amines on the brain of offsprings. Combined application of ethanol and diazepam to pregnant rats exerts marked effects upon the behavior of offsprings and causes a decreased content mainly of 5-HT and 5-HIAA in the investigated areas of the brain.