Morphological alterations in the prostate stroma of rats submitted to chronic nicotine treatment

Effects of nicotine on rat adrenal gland: crosstalk between oxidative and inflammatory markers, and amelioration by melatonin

Although the risks of smoking are well known, the effects of exposure to nicotine on endocrine functions remain unclear. We investigated the deleterious effects of nicotine on the adrenal gland and the mechanisms of these changes in rats. The role of melatonin in ameliorating pathological changes also was investigated. We used 24 rats divided into four groups of six: group 1, control; group 2, nicotine treated; group 3, nicotine and melatonin treated; group 4, melatonin treated. We used histology; immunohistochemistry of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and tyrosine hydroxylase (TH); measured oxidative and antioxidative markers, malondialdehyde (MDA) and glutathione (GSH); and performed real-time PCR for NF-κB 65, IL1-B and IL6. We also performed histomorphometric analysis. Indentation and lamellar separation of the adrenal capsule, vacuolated degenerated cells and lymphocytic infiltration were observed in group 2. Vacuolated cells and cells with pyknotic nuclei also were detected in the zona reticularis and medulla of the same group. We observed improved shape and cellular lining of the gland in groups 3 and 4. Widespread expression of iNOS, VEGF and TH, increased area percent collagen, decreased GSH (56%) and increased MDA, NF-κB, IL1-B and IL-6 were observed in group 2. All parameters were ameliorated in groups 3 and 4. The effects of nicotine on the adrenal gland can be attributed to oxidative and inflammatory stress; melatonin ameliorates these effects.

The prostate after castration and hormone replacement in a rat model: structural and ultrastructural analysis

Purpose:

To evaluate if late hormonal replacement is able to recover the prostatic tissue modified by androgenic deprivation.

Materials and Methods:

24 rats were assigned into a Sham group; an androgen deficient group, submitted to bilateral orchiectomy (Orch); and a group submitted to bilateral orchiectomy followed by testosterone replacement therapy (Orch+T). After 60 days from surgery blood was collected for determination of testosterone levels and the ventral prostate was collected for quantitative and qualitative microscopic analysis. The acinar epithelium height, the number of mast cells per field, and the densities of collagen fibers and acinar lumen were analyzed by stereological methods under light microscopy. The muscle fibers and types of collagen fibers were qualitatively assessed by scanning electron microscopy and polarization microscopy.

Results:

Hormone depletion (in group Orch) and return to normal levels (in group Orch+T) were effective as verified by serum testosterone analysis. The androgen deprivation promoted several alterations in the prostate: the acinar epithelium height diminished from 16.58±0.47 to 11.48±0.29μm; the number of mast cells per field presented increased from 0.45±0.07 to 2.83±0.25; collagen fibers density increased from 5.83±0.92 to 24.70±1.56%; and acinar lumen density decreased from 36.78±2.14 to 16.47±1.31%. Smooth muscle was also increased in Orch animals, and type I collagen fibers became more predominant in these animals. With the exception of the densities of collagen fibers and acinar lumen, in animals receiving testosterone replacement therapy all parameters became statistically similar to Sham. Collagen fibers density became lower and acinar lumen density became higher in Orch+T animals, when compared to Sham. This is the first study to demonstrate a relation between mast cells and testosterone levels in the prostate. This cells have been implicated in prostatic cancer and benign hyperplasia, although its specific role is not understood.

Conclusion:

Testosterone deprivation promotes major changes in the prostate of rats. The hormonal replacement therapy was effective in reversing these alterations.

General mechanisms of nicotine-induced fibrogenesis

Cigarette smoking contributes to the development of cancer, and pathogenesis of other diseases. Many chemicals have been identified in cigarettes that have potent biological properties. Nicotine is especially known for its role in addiction and plays a role in other physiological effects of smoking and tobacco use. Recent studies have provided compelling evidence that, in addition to promoting cancer, nicotine also plays a pathogenic role in systems, such as the lung, kidney, heart, and liver. In many organ systems, nicotine modulates fibrosis by altering the functions of fibroblasts. Understanding the processes modulated by nicotine holds therapeutic potential and may guide future clinical and research decisions. This review discusses the role of nicotine in the general fibrogenic process that governs fibrosis and fibrosis-related diseases, focusing on the cellular mechanisms that have implications in multiple organ systems. Potential research directions for the management of nicotine-induced fibrosis, and potential clinical considerations with regard to nicotine-replacement therapy (NRT) are presented.