الفهرس 
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Abstract
Zinc (Zn) is an essential mineral of exceptional biologic and public health importance. Zinc plays an important role in prostate, epididymal and testicular functions. Nanotechnology is a field of convergence among life sciences, material science and information technology. Among the many kinds of nanoparticles, nano-zinc oxide (nano-ZnO) showed a beneficial effect on spermatogenesis. The present study was conducted in mature male rats to determine the following:
1. A comparison between the effect of nano-ZnO and conventional-ZnO administration on: a) Some reproductive aspects of male rats. b) Some biochemical parameters in blood and testicular tissue. c) Serum and testicular testosterone concentration. 2. The effect of nano-ZnO on basal and LH-induced testosterone production from testicular tissue incubated in-vitro. <3. The possible protective effect of nano-ZnO on reproductive performance of male rats subjected to scrotal heating as a thermal damage (before and/or after heat). 4. The possible ameliorating effect of nano-ZnO on cadmium induced testicular damage. 5. The immuno-modulatory effect of nano-ZnO supplementation on leucocytes profile and antibody response of rats immunized with sheep RBCs. 6. The effect of nano-ZnO on the liver and kidney functions tests to clarify any harmful effect on these organs. Six main experiments were carried out:- The First Experiment: The aim of the 1st experiment was to compare between the effect of intra-peritoneal (I/P) injection of nano-ZnO or Conventional Zinc Oxide (cZnO) 5 mg / kg body weight on some reproductive parameters, serum biochemical, and testosterone hormone levels in mature male rats. Forty five mature male rats were allocated into three groups (15 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 48 days. The control group was injected with 0.5 ml physiological saline. The 2nd group was injected with 0.5 ml physiological saline containing 5 mg nano-ZnO / Kg body weight. The 3rd group was injected with 0.5 ml physiological saline containing 5 mg cZnO / Kg body weight. At days 15, 30 and 48 rats (5 from each group) were weighed, anaesthetized with ether for blood sampling then killed and the reproductive organs were weighted. Sera were collected for testosterone, zinc, and serum biochemical. Epididymis was used for sperm analysis. Testis was used for oxidative enzymes, testosterone, zinc measurements and histological examination. Results showed that 5 mg nano-ZnO / Kg B. wt for 30 and 48 day has beneficial effects on reproduction by significantly increasing reproductive organs weight, sperm motility, sperm concentration, serum testosterone, testicular testosterone, serum Zn, testicular Zn, ventral prostate Zn, testicular reduced glutathione, testicular catalase and high density of spermatozoa inside the seminiferous tubules; while the sperm abnormality, % of dead sperms and testicular malondialdahyde (MDH) were significantly decreased. These beneficial effects on reproduction were not found in the 5 mg nano-ZnO / Kg B. wt for 15 day or the 5 mg cZnO / Kg B. wt for 15, 30 and 48 day groups. The Second Experiment: The aim of the 2nd experiment was to determine the direct effect of nano-ZnO on testicular tissues culture for testosterone secretion in-vitro. Estimation of the direct effect of nano-ZnO on testosterone secretion of adult male rats was carried out by using testicular tissue incubation. The whole testicular tissues were obtained from 12 adult male rats (both right and left testes were used). The animals were sacrificed; testes were then immediately removed from scrotal sac and decapsulated. The whole testicular tissue (1g) was incubated in 1ml De Jalon fresh medium (acting as basal control) or medium with nano-ZnO at the dose of 0.15 and 0.3 mM /ml media (acting as treated). The tissues were also incubated with 10 IU human chorionic gonadotropin (hCG) alone in the medium (acting as hCG control) or in combination with nano-ZnO (0.15 and 0.3 mM /ml media). Aliquots of 100µl were then taken from each medium after 60 and 120 min of incubation for testosterone measurement. nano-ZnO (0.3 mM / ml media) and hCG co-administration to the testicular tissues incubation caused significant increase in the testosterone secretion after 60 and 120 min. While the nano-ZnO (0.15 mM / ml media) and hCG co-administration to testicular tissues and nano-ZnO alone caused insignificant variation. The Third Experiment: The aim of the 3rd experiment was to determine the possible beneficial effect of nano-ZnO (5 mg / kg body weight) on some reproductive parameters, serum biochemical and testosterone hormone levels in scrotally heated (thermal damage) mature male rat (before and/or after heat). The 3rd experiment was divided into 3 sub-exp. (A, B and C): Sub-exp. A) Before scrotal-heating nano-ZnO administration: Thirty mature male rats were allocated into 2 groups (15 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 30 days. 1st group was kept as a control group injected with 0.5 ml physiol. sal. 2nd group was injected with 0.5 ml physiological saline containing 5 mg nano-ZnO / Kg B. wt. At day 31 all the rats were subjected to scrotal heating. Sub-exp. B) After scrotal-heating nano-ZnO administration: Thirty mature male rats were subjected to scrotal heating then they were divided into 2 groups (15 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 48 days: 1st group was kept as a control group injected with 0.5 ml physiol. sal. 2nd group was injected with 0.5 ml physiol. saline containing 5 mg nano-ZnO / Kg B. wt. Sub-exp. C) Before & after scrotal-heating nano-ZnO administration: As experiment A but the treatment continued for 48 days after scrotal heating. At days 15, 30 and 48 from the scrotal heating, 5 rats from each group were weighed, anaesthetized with ether for blood sampling then killed and the reproductive organs were weighted. Sera were collected for testosterone, zinc, and serum biochemical. Epididymis was used for sperm analysis. Testis was used for oxidative enzymes, testosterone, zinc measurements and histological examination. Results showed that administration of nano-ZnO (5 mg / Kg B. wt) before scrotal heating and before & after scrotal heating has ameliorated the adverse effects of heat on male reproduction (compared to their control groups) by significantly increasing the reduced reproductive organs weight, sperm motility, sperm concentration, serum testosterone, testicular testosterone, testicular reduced glutathione, testicular catalase, serum Zn, testicular Zn, ventral prostate Zn, and spermatozoa inside the seminiferous tubules; while the sperm abnormality, % of dead sperm and testicular malondialdhyde were significantly decreased. These beneficial effects on reproduction were not found in the nano-ZnO administration after scrotal-heating group. The anti-oxidative stress effect of Zn prevented the oxidative damage of heat on reproduction. The Forth Experiment: This experiment was designed to determine the possible ameliorating effect of nano-ZnO on cadmium induced disruption of the blood-testes barrier (chemical damage). Twenty mature male rats were allocated into two groups (10 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 30 days. The control group received 0.5 ml physiological saline. The 2nd group received 0.5 ml physiological saline containing 5 mg nano-ZnO / Kg body weight. At day 31 from the beginning of the experiment all rats were I/P injected with evans blue (EB) dye (2% in saline, 4 ml/kg); then after 10 minutes a solution of cadmium chloride (10 mg / kg B. wt.) was injected S/C (5 rats from each group) and the other rats were saline injected. 24 hours after Cadmium chloride injection the rats were killed and the testes were removed to measure the concentration of EB dye in the tissue. Results showed that nano-ZnO co-administration with cadmium chloride caused a significant decrease in the testicular EB dye level. While the cadmium chloride administration only caused significant increase in the testicular EB level. The Fifth Experiment: The aim of the 5th experiment was to determine the effect of nano-ZnO supplementation on leucocyte profile and antibody responses of male rats immunized with sheep RBCs. Ten mature male rats were allocated into two groups (5 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 60 days. The 1st group (control group) was injected with 0.5 ml physiological saline and the 2nd group was injected with 0.5 ml physiological saline containing nano-ZnO (5 mg / Kg B. wt.). At day 30 of the beginning of the experiment all rats were injected with 0.3 ml of 10% sheep red blood cells (SRBC) suspension in normal saline per rat, followed by booster dose at day 45. The immune response of the rats was assessed (at days 30, 45 and 60) by using serum antibody response to sheep red blood cells (SRBC) by direct haemaggluination technique, total leucocyte count and differential leucocyte count. Results showed that nano-ZnO administration caused significant increase in the mean antibody titre, total leucocyte and lymphocyte count of male rats immunized with SRBC. While the neutrophil, monocyte, eosinophil and basophil counts showed insignificant variations. The Sixth Experiment: The aim of the 6th experiment was to determine the effect of nano-ZnO on some liver and kidney function tests to determine the safety level of using nano-ZnO. Ten mature male rats were allocated into two groups (5 rats / group). In all treatment regimens rats were injected I/P each 48 hour for 48 days. The 1st group (control group) was injected with 0.5 ml physiological saline and the 2nd group was injected with 0.5 ml physiological saline containing nano-ZnO (5 mg / Kg B. wt.). At day 49 of the beginning of the experiment all the rats were anaesthetized with ether for blood sampling to separate sera to measure aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea and creatinine. Results showed that nano-ZnO administration to adult male rats (5 mg / Kg B. wt) for 48 days caused insignificant variations in the serum AST, ALT, urea and creatinine compared to the control group. So it can be suggested that nano-ZnO is safe to be used on some liver and kidney function tests. The present study provided evidence which support the following:-1. Nano-Zinc (5 mg / Kg B. wt) for 30 and 48 days has some beneficial effects on male reproduction. While the nano-ZnO (5 mg / Kg B. wt) for 15 days and convential-Zinc (cZnO) (5 mg / Kg B. wt) for 15, 30 and 48 days does not. 2. Nano-ZnO (0.3 mM / ml media) and hCG co-administration to the testicular tissue incubation caused significant increase in the testosterone secretion in-vitro. 3. The use of nano-ZnO (5 mg / Kg B. wt) before scrotal heating and before & after scrotal heating ameliorated the adverse effects of thermal damage on male reproduction. While the nano-ZnO administered after heat does not. 4. The adverse effects of Cadmium chloride (10 mg / kg B. wt.) on the blood testes barrier were ameliorated with nano-ZnO (5 mg / Kg B. wt).5. Nano-ZnO (5 mg / Kg B. wt) enhanced the immune response of male rats immunized with SRBC. 6. Nano-ZnO (5mg /KgB.wt) is safe to be used with no alterations in liver and kidney function tests. In conclusion, from the findings of the present study it can be recommended to use nano-Zinc Oxide (nano-ZnO) rather than convential-Zinc as it gave better results on male reproduction with small safe doses on long term treatment compared to convential-Zinc. Nano-ZnO can be used to ameliorate the adverse effects of thermal and chemical damage on male reproduction. It can also be suggested to use nano-ZnO with the vaccination programs to enhance the immune response of the animal. Based on the results of the present study nano-ZnO is safe to be used with no alterations in liver and kidney functions. Further researches on other animal species and different doses are required to utilize the positive impact of nano-ZnO on production, reproduction and immune-stimulatory effects.