Evaluation of neuroprotection by melatonin against adverse effects of prenatal exposure to a nonsteroidal anti-inflammatory drug during peripheral nerve development.

The potential ability of melatonin to protect against impairment of the fetal peripheral nerve system due to maternal consumption of diclofenac sodium (DS) was investigated. Eighty-four pregnant rats were divided into seven groups: control (CONT), saline administered (PS), DS administered (DS), DS with low-dose melatonin administered (DS+MLT10), DS with high-dose melatonin administered (DS+MLT50), low-dose melatonin administered (MLT10), and high-dose melatonin administered (MLT50). After the pregnancy, six male newborn rats from each group were sacrificed at 4 and 20 weeks of age. Their right sciatic nerves were harvested, and nerve fibers were evaluated using stereological techniques. Mean numbers of myelinated axons, axon cross-section areas and the mean thickness of the myelin sheet were estimated. Four-week-old prenatally DS-exposed rats had significantly fewer axons, a smaller myelinated axonal area, and a thinner myelin sheath compared to CONT group (p<0.05). Although melatonin at both doses significantly increased axon numbers, only a high dose of melatonin increased the diameter of those axons (p<0.05). At 20-weeks of age, myelinated axon number in the DS group was not only significantly lower than all other groups (p<0.05) but also the cross-sectional area of these axons was smaller than all other groups (p<0.05). There were no differences between the groups regarding the mean thickness of the myelin sheet. The current study indicates that prenatal exposure to DS decreases the number and the diameter of sciatic nerve axons and that melatonin prophylaxis can prevent these effects.

The effect of prenatal exposure of a non-steroidal anti-inflammatory drug on the optic nerve of female rats: a stereological, histological, and electron microscopic study.

OBJECTIVE: Non-steroidal anti-inflammatory drugs (NSAIDs) can have adverse effects for in both mother and fetus following administration during the prenatal period. If given during pregnancy, diclofenac sodium (DS), an NSAID, is given during the pregnancy, may also affect the development of the central nervous system (CNS) or related structures. METHODS: Pregnant rats were separated into pure control (PG), saline (SG) and diclofenac groups (DG). A daily dose of 1 mg/kg of DS and 1 mL/kg saline was injected intraperitoneally to the DG and SG groups, respectively, from the 5th gestation day for a 15 day of period; the PG group received no treatment. After spontaneous delivery, female offspring were obtained from all groups. After the 20th week of postnatal life, the animals (n = 6 for each group) were perfused and the right optic nerves were resected. Sections were subjected to stereological and histological analysis. RESULTS: There were no significant differences (p > 0.05) between PG, SG and DG groups with respect to myelin thickness, axonal cross-sectional area, axon numerical density, total section area of optic nerve and axon number. CONCLUSIONS: Histological and stereological results indicated that treatment with DS or saline produced undesirable effects on female rat optic nerve development and myelinization with respect to morphology.

Prenatal exposure to a non-steroidal anti-inflammatory drug or saline solution impairs sciatic nerve morphology: a stereological and histological study.

The toxic effect of non-steroidal anti-inflammatory drugs (NSAIDs) during development has been widely investigated. While it has been shown that these drugs impair central nervous development and compromise the neural activity, the effects of these substances on the development of peripheral nerves are still not clarified. In the present study, sciatic nerves withdrawn from three experimental groups of 4-week-old rats, prenatally exposed to either saline solution, or diclofenac sodium, and controls not exposed to any substance, were evaluated in terms of axon number, cross-sectional area of axon and myelin sheet thickness as well as of the ultrastructure of nerve fibers. Comparisons of stereological estimations among these three groups showed that axon number and mean axon cross-sectional area, but not average myelin sheet thickness, were significantly decreased in rats that were exposed to both diclofenac sodium and also to the saline solution, in comparison of the control group. Electron microscope analysis revealed, in both treated groups, deterioration of myelin sheaths that was more pronounced in rats that were exposed to diclofenac sodium. Altogether, these findings show that the prenatal administration of both diclofenac sodium and saline solution impairs peripheral nervous system development, thus suggesting that this potential teratogenic effect should be also taken into consideration in the clinical use of these substances in pregnant patients.

Sertoli cell proliferation during the post hatching period in domestic fowl.

There has been no study aimed at directly determining of the periods of Sertoli cell proliferation in birds even domestic fowl. The aims of this study were to observe the cessation of post-hatching mitotic proliferation of Sertoli cells in domestic fowl, and to determine the volume density of Sertoli and germ cells during this period. A total of 50 Leghorn chicks were used in this study. The testes sections of the animals were immunostained with BrdU to observe the proliferation of cells from one to 10 weeks of age. The volume density of the Sertoli and germ cells were determined using the standard point counting method. The volume density of the germ cell nuclei was initially less than that of the Sertoli cells but the volume density converged by week 6, and remained relatively constant until the commencement of meiosis. Clear labeling of Sertoli and germ cells was observed from week 1 to week 7. The only those cells still labeled after 8 weeks were germ cells, indicating that Sertoli cell proliferation had ceased. Therefore, it is recommended that any research into the testes of domestic fowl should consider the cessation of Sertoli cell proliferation by approximately 8 weeks.