THE ULTRASTRUCTURAL LOCALIZATION OF NADPH-DIAPHORASE ENZYMATIC ACTIVITY IN THE LEYDIG CELLS OF MOUSE. EFFECTS OF ETHANOL ADMINISTRATION

Abstract The effects of the chronic ethanol treatment on the NOS-related NADPH-diaphorase activity were described in the mouse Leydig cells by means of transmission electron microscope. The recovery of the Leydig cells was also examined during a period of four weeks. About 10% of the Leydig cells showed various degrees of morphological alterations, consisting in increased number of lipid droplets, rarefaction and vacuolization of the cytoplasmic matrix. Other groups of Leydig cells (about 10%) revealed evident signs of degeneration. The NADPH-d activity was reduced both in apparently normal and injured Leydig cells and a moderate enzymatic reaction was only detected in the smooth endoplasmic reticulum. A week after the treatment an increased number of the degenerating Leydig cells and a further reduction of the enzymatic reaction were observed. Then, the Leydig cells showed a progressive recovery and four weeks after the treatment they exhibited a normal morphology and NADPH-d enzymatic reaction. These results demonstrated for the first time the inhibition of NOS activity in the Leydig cells after chronic ethanol administration

Effects of chronic ethanol administration on the NOS-related NADPH-diaphorase activity in the mouse Leydig cells

INTRODUCTION - Nitric oxide (NO) is a free radical involved in several physiological and pathological processes (1). NO appears to be involved in crucial aspects of male genital physiology, including relaxation of corpora cavernosa and inhibition of sperm mobility and testosterone secretion (2). The gonadotoxic effects of the alcohol were well documented in humans and in animal models (2, 3). In-deed, ethanol administration has been shown to cause morphological alterations on seminiferous tubules (2) and Leydig cells (3) and to decrease testosterone and LH plasmatic levels (4). We examined by TEM the effects of chronic ethanol treatment on the NADPH-diaphorase (NADPH-d) activity in the mouse Leydig cells. MATERIAL AND METHODS - Ten adult Wistar mice were treated with ethanol 0.5g/Kg/die intragastrically for two weeks. The animals were anaesthetised, perfused by aldehydes and treated for NADPH-d histochemistry (5). Specimens incubated with NADPH-free medium were utilised as controls. In order to test the specificity of NADPH-d staining for NOS activity, some specimens were immersed in the medium containing 0.3 mM iodonium diphenyl (6). The specimens were post-fixed in osmium tetroxide, and embedded in Epon 812. RESULTS AND DISCUSSION - About 20% of Leydig cells of the ethanol-treated mice showed morphological alterations. The cells were characterised by irregular protrusions of the plasmatic membrane, rarefaction of the cytoplasmic matrix and increased number of lipid droplets. Irregular mitochondria were also observed. Some Leydig cells (about 10%) showed signs of degeneration. As regards the enzymatic study, the controls animals exhibited the NADPH-d activity in the nuclear cistern, mitochondria and SER. In the ethanol treated-mice the enzymatic reaction was strongly reduced both in apparently normal and injured Leydig cells. A moderate reactivity was detected only in the SER. These findings suggest that chronic ethanol treatment inhibits the NOS-related NADPH-d activity in the Leydig cells of mouse. This effect could be a consequence of the impaired synthesis of the testosterone, inducing an inhibition of NO production through a negative feedback mechanism. However it can not be excluded a direct action of the alcohol on the NOS/cGMP enzymatic pathway

The roles of roads and agricultural land use in altering hydrological processes in Nam Mae Rim watershed, northern Thailand

10.1002/hyp.7039Hydrological Processes22224339-4354HYPR

Epixenosomes, peculiar epibionts of the ciliated protozoon Euplotidium itoi : what kind of organisms are they?

Epixenosomes live on the dorsal surface of their ciliate host, Euplotidium itoi. They lack a nuclear envelope and divide like prokaryotes. On the other hand they have a morphological and functional cell compartmentalization and possess tubules that are sensible to tubulin inhibitors and positively react with different antitubulin antibodies. In the present paper, as a first step to investigate their real nature, the in situ hybridization technique was applied at the ultrastructural level. Different prokaryotic and eukaryotic probes suitable for detecting rRNA genes were used. An additional test was performed with the gene encoding for \u3b2 tubulin in the ciliate Euplotes crassus. Positive results, evidenced by a precise localization of gold particles, were obtained with all the eukaryotic probes used. These probes were obtained from organisms belonging to three different kingdoms (Protista, Animalia, Plantae). On the contrary, no hybridization was obtained with prokaryotic probes, not even when the probe used was an oligonucleotide complementary to all bacterial 16S rRNA so far sequenced. On the basis of these results and of the other observations so far accumulated, the possible eukaryotic nature of epixenosomes is discussed