Influence of 50 Hz magnetic field on sex hormones and other fertility parameters of adult male rats

The effects of an extremely low frequency (ELF) magnetic field on the sex hormones and other fertility parameters of adult male Sprague-Dawley rats were investigated. Adult male rats were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 microT (rms) for 18 consecutive weeks. There were no significant effects on the absolute body weight and the weight of the testes of the exposed rats. However, the weights of seminal vesicles and preputial glands were significantly reduced in the exposed male rats. Similarly, a significant reduction in sperm count was observed in the exposed group. Furthermore, there were no significant effects on the serum levels of male follicle stimulating hormone (FSH) during the 18 weeks of exposure period. On the other hand, there was a significant increase in the serum levels of male luteinizing hormone (LH) after 18 weeks of exposure (P < .005), while testosterone levels were significantly decreased only after 6 and 12 weeks of the exposure period. These results suggest that long term exposure to ELF could have adverse effects on mammalian fertility and reproduction.     

The effect of sex steroid hormones on interhemispheric asymmetry in rats]

The effect of gonadectomy and sex-steroid hormones treatment on functional interhemispheric asymmetry to the reaction of pain cry avoidance of another species (emotional reactions) and motor and exploratory activity of open-field behavior in Wistar rats of 3 months old has been investigated. A spreading depression technique for hemisphere inactivation has been used. The hemispheric asymmetry of the reactions in intact rats was characterized by sex dimorphism; the left hemisphere dominated to a great extent in males than in females under the control of emotional reactions; in motor and exploratory activity in open-field behavior of rats the left hemisphere dominated in males and the right one--in female. In both sexes the neonatal gonadectomy levelled the interhemispheric differences in reactions under investigation. The following treatment of females with estradiol and males with testosterone didn't restore the asymmetry. After the castration at the age of 3 months the correlation between the size and direction of interhemispheric differences became reverse. The treatment of females with testosterone and males with estradiol both castrated in adulthood restored the interhemispheric asymmetry in males and had no effect in females. The treatment of intact rats with hormones of opposite sex led to the enhancement of left hemisphere dominance in motor and exploratory activity in males and levelled the asymmetry in females. It has been shown that in adult rats sex-steroids effect predominantly the right hemisphere.     

Influence of 50 Hz magnetic field on sex hormones and body, uterine, and ovarian weights of adult female rats

The effects of extremely low-frequency (ELF) magnetic fields on sex hormones of adult female Spague-Dawley rats were investigated. Adult female rats were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 microT (rms) for 18 weeks before they returned to their normal life with unexposed counterparts. Serum level of Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), progesterone, and estrogen were measured before, after, and during the exposure. Body and uterine weights were not affected by the field. A significant reduction in absolute and relative ovarian weights in exposed rats was observed when compared with sham-exposed controls (P < 0.05). The reduction in the levels of gonadotropins (FSH and LH) was significant after six weeks of exposure (P < 0.005). FSH levels were affected only on week 6 of exposure while LH remained affected during at 12 and 18 weeks (P < 0.05). Interestingly, no significant effects were found at 6 and 12 weeks after removing the field. The level of progesterone and estrogen was significantly decreased after 12 weeks of exposure (P < 0.05), while no other effects on progesterone level was observed during exposure or after removing the exposure. The level of estrogen was also significantly reduced at 12 weeks after removing the field (P < 0.05). These results suggest possible adverse effect on mammalian fertility and reproduction. The effects of ELF-MF on sex hormones were shown to be partly reversible.     

The regulation of male sexual behavior by the sex hormones

The article provides a review of the clinical and experimental data, both published and the author's own observations. They demonstrate that the hormone regulation of sex behaviour takes place at the central and the peripheral levels. The major role is played by androgenes, of which testosterone is the main regulator of sex appeal (libido, courtship behaviour in animals), while the most important regulator of ejaculation, in particular, of the time of ejaculation, is the non-aromatized androgene dihydrotestosterone (DHT). There is no rigid correlation between the level of sex activity and the level of androgenes, if the latter are within the normal individual and physiological range. However, both in case of hypo- and hyperendrogeny, the observations indicate depression of sexuality, though the mechanism of the depression are different. The author established the optimal levels of androgenes, which maintain the individual elements of the sexual act. The role of estrogene in regulation of the male sex appeal is not yet clear. As a rule, use of estrogenes results in depression of the male sexuality. At the same time, combination of DHT and estradiole (in laboratory and productive animals) leads to normalisation of erection and ejaculation disorders. These result is, probably, due to the central effect of estrogene, which prolongs the DHT effect and censures its accelerated penetration into cellular neuronal structures, as well as to the peripheral effect of DHT.     

The effect of ovarian hormones on antioxidant enzyme activities in the brain of male rats

The brain is widely responsive to gonadal hormones. The functional significance of ovarian hormones in the brain is evident from biochemical studies indicating that estradiol or progesterone treatment of testectomized rats produces changes of antioxidant enzyme activities. The effect of estradiol benzoate (EB) and progesterone (P) in the control of antioxidant (AO) enzyme activities was studied in the brain of adult male Wistar rats. The activities of catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glutathione reductase (GR) were measured in appropriate subcellular fractions, prepared from brains of animals belonging to various experimental groups. These groups were designed with the intention to follow changes in enzyme activities 2 h or 24 h after systemic administration of 5 microg EB or 2 mg P to testectomized (TX) animals. The obtained results show that both EB and P increase CAT activity, whereas EB decreases GSH-Px, GST and GR activities. These findings clearly show the modulatory role of EB and P in the control of enzymes responsible for the protection of rat nerve cells against oxidative damage caused by free oxygen radicals.     

The effect of oleanolic acid on sperm motion characteristics and fertility of male Wistar rats

The study was designed to examine the effect of oleanolic acid on cauda epididymal sperm motion using a computer-aided sperm analysis system and to elucidate the relationship between sperm motion and fertility, as a tool for contraceptive studies. Oleanolic acid-polyvinylpyrrollidone suspension was orally administered to adult male Wistar rats for 30 days, followed by a 14-day drug withdrawal from half of the rats in the group. Control rats received only polyvinylpyrrollidone. All males were mated with untreated females. Treated males failed to impregnate females, whereas control and oleanolic acid withdrawn males achieved 100% pregnancies. Sperm motion analysed on the Sperm Motility Quantifier (SMQ) showed significant differences in linearity (P < 0.001) and wobble (P < 0.01) between control and treated groups. However, the curvilinear velocities were not significantly different (P > 0.05) among all the groups. Sperm motility patterns verified differences among kinematic parameters.     

The effect of Red Seaweed (Chondrus crispus) on the fertility of male albino rats

At different parts of the world, Red Seaweeds are one component of human diets especially at Southeast Asia. Red Seaweeds structurally contain bioactive molecules so; we studied the effect of Chondrus crispus on increasing the male albino rat fertility. Twelve male albino rats are used in this study as two group pre-treated group and post- treated one each with 6 animals. The pretreated group was dissected before the post-treated group injection. Each post treated rat injected intramuscular with 1 mg of Chondrus crispus with dose 0.1 ml/ twice per week for 48 day (Mukhtar et al., 2013).The results showed that increasing on the total testosterone levels insignificantly, sperm motility significantly, and decreasing in both FSH and DPPH levels insignificantly and significantly for the MDA levels in the post-treated group. The morphological appearance and histological examination for the sperm, testis and liver were normal as the pretreated group. The molecular studies showed absence of any DNA fragmentation for the testis of both group.The Red Seaweed has an enhanced effect in the testicular function of the animal which might increase their fertility and sexual activities.     

P-aminodiphenylamine induced biochemical changes in sex organs of male albino rats.

Intraperitoneal administration of p-aminodiphenylamine (p-ADPA), an aromatic amine of wide industrial applications, / 42.5 mg/kg body weight for 180 days significantly decreased the activities of testicular lactate dehydrogenase and hyaluronidase and lactic acid content indicating arrest of spermatogenesis. Patchy necrosis of the testis was confirmed histopathologically. No change in testicular cholesterol, fructose content of coagulating glands and dorso-lateral prostate and activities of alkaline phosphatase in seminal vesicle and acid phosphatase in ventral prostate support normal androgenic status.     

Differential regulation of insulin resistance and hypertension by sex hormones in fructose-fed male rats

Differences in gender are in part responsible for the development of insulin resistance (IR) and associated hypertension. Currently, it is unclear whether these differences are dictated by gender itself or by the relative changes in plasma estrogen and/or testosterone. We investigated the interrelationships between testosterone and estrogen in the progression of IR and hypertension in vivo in intact and gonadectomized fructose-fed male rats. Treatment with estrogen significantly reduced the testosterone levels in both normal chow-fed and fructose-fed rats. Interestingly, fructose feeding induced a relative increase in estradiol levels, which did not affect IR in both intact and gonadectomized fructose-fed rats. However, increasing the estrogen levels improved insulin sensitivity in both intact and gonadectomized fructose-fed rats. In intact males, fructose feeding increased the blood pressure (140 +/- 2 mmHg), which was prevented by estrogen treatment. However, the blood pressure in the fructose-fed estrogen rats (125 +/- 1 mmHg) was significantly higher than that of normal chow-fed (113 +/- 1 mmHg) and fructose-fed gonadectomized rats. Estrogen treatment did not affect the blood pressure in gonadectomized fructose-fed rats (105 +/- 2 mmHg). These data suggest the existence of a threshold value for estrogen below which insulin sensitivity is unaffected. The development of hypertension in this model is dictated solely by the presence or absence of testosterone. In summary, the development of IR and hypertension is governed not by gender per se but by the interactions of specific sex hormones such as estrogen and testosterone.     

Effect of sex hormones on renal estrogen and angiotensin type 1 receptors in female and male rats

Although the mechanisms are not understood, evidence suggests that 17beta-estradiol (E2) confers protection from cardiovascular and renal complications in many diseases. We have reported that E2 decreases angiotensin type 1 receptors (AT1Rs) in different tissues and hypothesize that E2 exerts tonic inhibition on AT1Rs, reducing effects of ANG II. This study determined the effects of E2 and dihydrotestosterone (DHT) on cortical estrogen receptors (ERs) and glomerular AT1R binding in rats. Animals underwent sham operation, ovariectomy (Ovx) or orchidectomy (Cas) and were treated (Ovx +/- E2; Cas +/- DHT) for 3 wk. Cortical ERalpha protein was 2.5 times greater, and ERbeta was 80% less in females vs. males (P < 0.01). Glomerular AT1R binding was lower in females than males [4,657 +/- 838 vs. 7,457 +/- 467 counts per minute (cpm), P < 0.01]. Ovx reduced ERalpha protein by 50%, whereas E2 increased ERalpha expression after Ovx. The decrease in cortical ERalpha in Ovx rats was associated with a significant increase in AT1R binding (6,908 +/- 609 cpm), and E2 prevented this increase. There was no change in ERalpha or AT1R binding following Cas +/- DHT (25 mg) treatment, although Cas did elevate cortical ERbeta (P < 0.01). Interestingly, the high dose DHT (200 mg) elevated ERalpha 150% above intact levels and profoundly decreased AT1R binding (1,824 +/- 705 cpm, P < 0.001 vs. intact male). This indicates that under normal conditions, glomerular AT1R binding is significantly greater in male than female animals, which may be important in development of cardiovascular and renal disease in males. Furthermore, E2 regulates ERalpha and is inversely associated with glomerular AT1R binding, supporting our hypothesis that E2 tonically suppresses AT1Rs and suggesting a potential mechanism for the protective effects of estrogen.