Ultrastructural lesions in testes from hyperprolactinemic men

Risperidone induced reproductive toxicity in male rats targeting leydig cells and hypothalamic-pituitary-gonadal axis by inducing oxidative stress

Risperidone (RIS), a commonly used drug during a lifetime for the treatment of schizophrenia, causes some adverse effects in the male reproductive system; however, there is no comprehensive reproductive toxicity study of RIS. For this purpose, male rats were administered orally for 1.25, 2.5 and 3 mg/kg RIS for 28 days and the sperm count, motility, morphology, DNA damage and the histological changes in testicular tissue were evaluated. Follicle-stimulating hormone (FSH), luteinising hormone (LH) and serum levels of testosterone, which are the main hormonal regulators of reproduction, and testicular glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels as the indicators of oxidative stress were determined. Normal sperm morphology was decreased in RIS groups and histopathological degeneration occurred in testis tissue dose-dependently. Serum LH levels were not altered; however, FSH and testosterone levels decreased in the high-dose group. Histopathologic examination showed RIS toxicity targeted Leydig cells, which might be associated with impairment of the hypothalamic-pituitary-gonadal (HPG) axis. GSH levels were decreased and MDA levels were increased in the high-dose group which was evaluated as indicators of oxidative stress. In conclusion, RIS caused reproductive toxicity in male rats by inducing oxidative stress and disrupting hormonal regulation.

The treatment with cabergoline for 24 month normalizes the quality of seminal fluid in hyperprolactinaemic males

BACKGROUND

Alterations of sperm number and motility are found in hyperprolactinaemic men. Cabergoline treatment reverses alterations in semen. No information is currently available on the quality of seminal tests in hyperprolactinemia in response to cabergoline treatment.

OBJECTIVE

To further investigate the effect of hyperprolactinaemia and its treatment with cabergoline on semen quality.

PATIENTS

Forty-three men with hyperprolactinaemia (32 macro- and 11 micro-prolactinomas); 60 healthy men served as control.

METHODS

Live spermatozoa count, sperm membrane function, kinetic index, nuclear DNA integrity, sperm curvilinear and linear velocity and amplitude of lateral movement of the sperm head were investigated before and after 6 and 24 months of treatment with cabergoline.

STUDY DESIGN

Open prospective.

RESULTS

At study entry, semen functional tests were severely and similarly impaired both in patients with macro- and micro-prolactinomas compared to controls. After 6 and 12 months of treatment there was a significant improvement of semen quality in patients achieving normalization of prolactin levels, although most of the parameters remained lower than in controls. After 24 months of treatment, seminal fluid characteristics were similar to the controls except for live spermatozoa count, sperm membrane function, sperm kinetic index and sperm nuclear DNA integrity, which remained abnormal in 9.3-53% of the patients.

CONCLUSIONS

Twenty-four months of cabergoline treatment restored gonadal function in 66.7% of men with hyperprolactinaemia.

Successful gonadotrophin treatment of hypogonadism in postoperative patients with macroprolactinoma and persistent hyperprolactinaemia

We report on two males with prolactinoma in whom hyperprolactinaemia and hypogonadism persisted for several years postoperatively despite the administration of a dopamine agonist or bromocriptine. In these patients, a GnRH test revealed no response in the levels of serum LH or FSH. An hCG stimulation test provoked no response in the serum levels of testosterone. Case 1, who was 28 years old at the first visit, received parenteral testosterone and appreciable virilization of the genitalia was noted within a few months. When he married and desired to father a child, the treatment was switched to hCG/hMG combined therapy and spermatozoa appeared subsequently in the ejaculate, although their numbers were low. His wife conceived and delivered a healthy baby girl. Case 2 was a single young man who presented with hypogonadotrophic hypogonadism and hyperprolactinaemia. He was started on hCG injections three times per week and the maturation of his genitalia was advanced rapidly. Semen analyses showed sperm concentration and motility to be within the normal range. Post-treatment GnRH test revealed no improvement in gonadotrophin responses for LH or FSH. In both cases, the hCG test repeated after the gonadotrophin treatment showed normal basal and stimulated testosterone levels. During the course of gonadotrophin treatment in these cases, serum prolactin levels remained elevated, and it is suggested that, in the two cases, the hypothalamo-pituitary function was disturbed by the tumour or its manipulation and the capacity of the pituitary gland to secrete gonadotrophin was impaired. Under such circumstances with persisting hyperprolactinaemia, hCG and/or hCG/hMG combination treatment can induce normal virilization and advance spermatogenesis sufficiently to achieve fertility.

Routine hormone load tests are unnecessary in infertile men

A sample of 225 men examined at the Infertility Service Unit of this hospital had spermiograms, standardized in accordance with WHO guide lines, and a hormone stimulation test with injection of gonadotropin releasing hormone, thyrotropin releasing hormone, and ACTH. The serum concentrations of the following hormones were assessed: follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, oestradiol (E), thyroid stimulating hormone, cortisol, 21-desoxycortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, dehydroepiandrosteronesulphate, androstenedione, testosterone (T), and dihydrotestosterone. The results of the spermiograms were found to be related to the concentrations of the following hormones: FSH, LH, T, and E. Thyroid and adrenal function in men without signs of endocrinological diseases failed to influence spermatic parameters.

Evaluation of spermatozoa of the rat in hyperprolactinaemia induced by metoclopramide

Metoclopramide (MCP) in doses of 2.2 mg kg-1 body weight, being administered intraperitoneally to rats for 14 d, provokes a premature release of germ cells in the testes. The number of spermatozoa is reduced. In addition the spermatozoa exhibit defects of head and tail structures. After the administration of MCP for 14 d, followed by a 14-d break in applying the drug, the number of spermatozoa in the lumen of the epididymal duct continues to be low. Many spermatozoa are damaged. Only after a 66-d-break in MCP administration is the morphology of the seminiferous epithelium restored, and a large number of spermatozoa appear in the lumen of the epididymal duct.

Hormone load tests in infertile male patients

The recognition that discreet hormonal abnormalities may cause ovulation disorders in women suggested that the male partner of infertile women might also suffer from unrecognized hormonal dysfunction amendable to substitution therapy. We obtained a combined stimulation test with gonadotropin-releasing hormone (GnRH), thyreotropin-releasing hormone (TRH), and ACTH in 225 males with childless spouses, when the couple sought to have children for at least one year. The following hormone levels were determined: estradiol (E), thyroid-stimulating hormone (TSH), prolactin, testosterone (T), dihydrotestosterone (DHT), androstenedione(A), 17-OH-pregnenolone (17-OH-Preg), 17-OH-progesterone (17-OHP), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), cortisone (F), and 21-desoxycortisone (21DF). Basal and stimulated, and adrenal-testicular steroids with and without ACTH stimulation failed to demonstrate a relevant relationship to semen parameters. Gonadotropin levels had a significant negative correlation to all important semen parameters (testicular volume, sperm count, motility, morphology, and vitality) and were positively correlated to spermiogenetic defects. Stimulated LH values were more clearly associated with spermiogenetic defects than basal LH. Nonetheless, basal FSH concentrations were more informative than LH. Stimulated prolactin values were positively correlated with both gonadotropin and with sperm morphology. E concentrations had a significant positive correlation with both basal and poststimulation DHEAS values, and showed a highly negative correlation with sperm count, morphology, and vitality. In comparison, good sperm parameters were associated with high poststimulation T concentrations. The results of this study suggest that basal FSH and E concentrations, as well as the stimulated LH, T, and prolactin determinations, should be included in the evaluation of male sterility.

Sustained hyperglycemia results in testicular dysfunction and reduced fertility potential in BBWOR diabetic rats

Rats with short-term diabetes show a greater than 50% reduction of serum testosterone and increased lipid in Leydig cells but normal testicular structure. The purpose of this study was to determine the extent of testicular pathology (morphology index), integrity of the blood-testis barrier, daily sperm production (DSP), number of Leydig cells per testis (LC/T), and total trunk testosterone (TTT) in diabetic rats (BBWORdp) with long-term hyperglycemia (300-350 mg/dl for greater than 180 days) and to evaluate its effects on fertility potential. Results were compared with similarly aged normoglycemic rats (BBWORdr) and normal control Wistar rats. After 6 mo of diabetes, testis weights, DSPs, TTTs, and the morphology index were significantly reduced. The LC/T was not different from BBWORdr rats. The blood-testis barrier appeared intact, although structural abnormalities were noted in Sertoli-Sertoli junction complexes. There was a significant reduction in the number of pregnancies per rat and implantations per pregnancy in matings utilizing the diabetic BBWORdp rat and control Wistar female rats. Results indicate that long-term diabetes with sustained hyperglycemia leads to significant testicular dysfunction associated with decreased fertility potential.

Interstitial compartment pathology and spermatogenic disruption in testes from impotent diabetic men

Studies utilizing animal models of diabetes suggest that diabetic complications of impotence involve structural lesions in the testis as part of an overall defect in the pituitary-testicular axis. In the present study testicular biopsies from ten oligospermic and/or impotent men with diabetes were evaluated by light and electron microscopy. One biopsy was judged normal. The remaining tissue showed variable testicular pathology ranging from minimally to grossly affected. Seminiferous tubules had decreased tubule diameters, hyalinized tubule walls, and occluded lumina owing either to epithelial encroachment or cellular debris and exfoliated round germ cells. Sertoli cells were vacuolated and showed a high degree of apical cell membrane redundancy and degeneration. Although Sertoli-Sertoli cell junctional complexes appeared normal, Sertoli junctional specializations associated with spermatids were structurally abnormal or absent. All tubules were variably depleted of adluminal compartment germ cell types. The interstitial compartment was filled with a collagen-rich extracellular matrix concentrated around small blood vessels and seminiferous tubule walls. Capillaries and lymphatic endothelia appeared structurally abnormal and compromised by the interstitial "matrix expansion." Some Leydig cells contained a variable number of small to large lipid droplets, vacuoles, and secondary lysosomes. Results indicate the presence of tissue pathology in testes of impotent diabetic men. Discrete ultrastructural lesions in apical Sertoli cell cytoplasm are associated with spermatogenic disruption and morphological changes in the interstitial compartment suggest microvascular complications.

Hormone profile in hyperprolactinemic infertile men

Serum levels of FSH, LH, prolactin, testosterone, and estradiol in 46 infertile men with hyperprolactinemia were compared with the same in 50 infertile and 30 fertile men with normal serum prolactin levels. Serum FSH levels in hyperprolactinemic men were significantly higher than in the other groups, indicating disturbance of spermatogenic process among those men. Significantly raised serum LH levels were in infertile men with serum prolactin over 1000 U/liter. All men with hyperprolactinemia had significantly lower serum testosterone levels than other infertile and fertile men. Although serum testosterone was not under the lower limit of normal range and high LH levels demonstrated disturbance of Leydig cell function in hyperprolactinemic infertile men, serum estradiol levels were not different among investigated groups. Azoospermic men with raised serum prolactin had higher serum FSH and LH levels than oligospermic men with hyperprolactinemia. These data demonstrated disturbance in hypothalamopituitary-testicular axis in infertile men with hyperprolactinemia. Further studies of prolactin in males with reproductive failure could probably clear this problem.