Biomedical subjects

E Sasso-Cerri

Publications and source records attributed to E Sasso-Cerri.

5 recordsLinked to original sources

PubMed2005

Testosterone-immunopositive primordial germ cells in the testis of the bullfrog, Rana catesbeiana.

In amphibia, steroidogenesis remains quiescent in distinct seasonal periods, but the mechanism by which spermatogenesis is maintained under low steroidogenic conditions is not clear. In the present study, testosterone location in the testes of Rana catesbeiana was investigated immunohistochemically during breeding (summer) and nonbreeding (winter) periods. In winter, the scarce interstitial tissue exhibited occasional testosterone immunopositivity in the interstitial cells but the cytoplasm of primordial germ cells (PG cells) was clearly immunopositive. By contrast, in summer, PG cells contained little or no immunoreactivity whereas strong immunolabelling was present in the well-developed interstitial tissue. These results suggest that PG cells could retain testosterone during winter. This androgen reservoir could be involved in the control of early spermatogenesis in winter and/or to guarantee spermiogenesis and spermiation in the next spring/summer. The weak or negative immunoreaction in the summer PG cells might reflect consumption of androgen reservoir by the intense spermatogenic activity from spring to summer. Thus, besides acting as stem cells, PG cells of R. catesbeiana could exert an androgen regulatory role during seasonal spermatogenesis.

Animals↗

PubMed2003

Staining methods applied to glycol methacrylate embedded tissue sections.

The use of glycol methacrylate (GMA) avoids some technical artifacts, which are usually observed in paraffin-embedded sections, providing good morphological resolution. On the other hand, weak staining have been mentioned during the use of different methods in plastic sections. In the present study, changes in the histological staining procedures have been assayed during the use of staining and histochemical methods in different GMA-embedded tissues. Samples of tongue, submandibular and sublingual glands, cartilage, portions of respiratory tract and nervous ganglion were fixed in 4% formaldehyde and embedded in glycol methacrylate. The sections of tongue and nervous ganglion were stained by H&E. Picrosirius, Toluidine Blue and Sudan Black B methods were applied, respectively, for identification of collagen fibers in submandibular gland, sulfated glycosaminoglycans in cartilage (metachromasia) and myelin lipids in nervous ganglion. Periodic Acid-Schiff (PAS) method was used for detection of glycoconjugates in submandibular gland and cartilage while AB/PAS combined methods were applied for detection of mucins in the respiratory tract. In addition, a combination of Alcian Blue (AB) and Picrosirius methods was also assayed in the sublingual gland sections. The GMA-embedded tissue sections showed an optimal morphological integrity and were favorable to the staining methods employed in the present study. In the sections of tongue and nervous ganglion, a good contrast of basophilic and acidophilic structures was obtained by H&E. An intense eosinophilia was observed either in the striated muscle fibers or in the myelin sheaths in which the lipids were preserved and revealed by Sudan Black B. In the cartilage matrix, a strong metachromasia was revealed by Toluidine Blue in the negatively-charged glycosaminoglycans. In the chondrocytes, glycogen granules were intensely positive to PAS method. Extracellular glycoproteins were also PAS positive in the basal membrane and in the region occupied by the lamina externa and reticular fibers surrounding each smooth muscle cells of the blood vessels. In the epithelial cells of the respiratory tract, acid and neutral mucins were histochemically detected by AB and PAS methods, respectively. Moreover, granules containing acid and neutral mucins were revealed in purple by AB and PAS concomitantly. In the sublingual gland sections, a distinct affinity of acid mucins by AB (in turquoise-blue) and collagen fibers by Picrosirius (in red) was obtained when these methods were combined. Although some routine dyes used in paraffin sections have showed a weak stain in historesin sections, our results showed that different dyes could be applied in GMA sections if modified staining procedures were assayed. Therefore, appropriate staining contrast and, thus, detection of one or different substances in a same section can be acquired in association to the good morphological resolution provided by GMA.

Alcian Blue↗

PubMed2002

In situ demonstration of both TUNEL-labeled germ cell and Sertoli cell in the cimetidine-treated rats.

Cimetidine has caused dysfunction in the male reproductive system. In the rat testis, intratubular alterations and loss of peritubular tissue due to peritubular myoid cell death by apoptosis have been recently shown. Thus, the aim of this study is to evaluate which cells of the seminiferous epithelium have been affected and/or died by apoptosis after the treatment with cimetidine. For this purpose, an experimental group containing five male albino Wistar rats received intraperitoneal injections of cimetidine (50 mg/kg body weight) during 52 days. The testes were fixed with 4% buffered formaldehyde and were embedded in paraffin. For detection of DNA breaks (apoptosis) in the cells of the seminiferous epithelium, the testicular sections were treated by the TUNEL method (Apop-Tag Plus Peroxidase Kit). In the tubules affected by cimetidine, altered peritubular tissue, including the presence of TUNEL labeling in the myoid peritubular cells, were usually found. In these tubules, the seminiferous epithelium exhibited low density of germ cells and TUNEL-positive labeling in the germ cells of the basal compartment. The concomitant staining in both germ cells of the basal compartment and late spermatids suggest a sensitivity of these cells in the damaged tubules. Besides germ cells, TUNEL-positive Sertoli cells were also found in the injured seminiferous tubules. Thus, a relationship between dying germ cells and Sertoli cell damage and/or death must be considered in tubules where peritubular tissue has been affected by toxicants.

Animals↗

PubMed2000

Cimetidine (Tagamet) is a reproductive toxicant in male rats affecting peritubular cells.

Cimetidine (Tagamet) is a potent histaminic H2-receptor antagonist, extensively prescribed for ulcers and now available without prescription. Cimetidine is a known testicular toxicant, but its mechanism of action remains uncertain. Rats were treated i.p. with cimetidine either at 50 mg/kg or 250 mg/kg body weight for 59 days. Accessory sex organ weights, but not testis weight, were significantly reduced in the high dose treated groups. FSH levels were significantly elevated in both treated groups, but testosterone levels were unchanged. A high degree of variability characterized testis histology, with most tubules appearing normal and some tubules (15-17%) partially lacking or devoid of germ cells. Morphometry showed that although seminiferous tubule volume was not significantly changed, the volume of peritubular tissue was reduced in the high dose group. There was extensive duplication of the basal lamina, lamina densa in both apparently normal spermatogenic tubules and severely damaged tubules. Apoptotic peritubular myoid cells were also found. TUNEL labeling confirmed extensive apoptotic cell death in peritubular cells, but revealed apoptosis of vascular smooth muscle. Given that 1) peritubular myoid cell apoptosis occurs in apparently normal tubules, that 2) basal lamina disorders are found, and that 3) peritubular cells are lost from the testis, it is suggested that the primary event in cimetidine-related damage is targeted to testicular smooth muscle cells. This is the first in vivo-administered toxicant to be described that targets myoid cells, resulting in abnormal spermatogenesis.

Animals↗

PubMedDate not supplied

Morphological alterations and intratubular lipid inclusions as indicative of spermatogenic damage in cimetidine-treated rats.

Doses of cimetidine (50 mg/kg b/w) were administered to adult male Wistar rats over 52 consecutive days. Besides plasma testosterone levels, morphological and morphometric aspects of the seminiferous tubules as well as histochemical analysis of the lipid content by oil red O were emphasized. Abnormal tubules exhibiting disorganization of their cellular association, loss of germ cells, and multinucleated giant spermatids were usually found. Significant reductions of testis weight and tubular diameter at specific stages (VII-IX), as well as lack of contact between Sertoli cells and spermatids in tubules at stage IX, suggest a possible interference of cimetidine on the histoarchitecture of the seminiferous epithelium. The dense concentration of lipid inclusions in tubules at postspermiation stages indicates phagocytosis and degradation of germ cells. Since no change in serum testosterone levels was verified in cimetidine-treated rats, the authors could not exclude the possibility that besides an antiandrogenic effect, other biochemical factors necessary for normal spermatogenesis could be involved in the testicular alterations.

Androgen Antagonists↗