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At least 19 recordsLinked to original sources

Stimulation of spermatogenesis and biological paternity by intranasal (low dose) gonadotropin-releasing hormone (GnRH) in a male with Kallmann's syndrome: intraindividual comparison of GnRH and gonadotropins for stimulation of spermatogenesis.

Intranasal (in) GnRH spray caused induction and maintenance of spermatogenesis and biological paternity in a 28-yr-old man with Kallmann's syndrome. Prior treatment had included GnRH analog administration, which failed to induce puberty, and testosterone (T) enanthate weekly. Prior hCG/human menopausal gonadotropin therapy had resulted in high normal serum T levels and near-normal semen quality, but during subsequent hCG therapy, spermatogenesis markedly decreased. The patient had then received 250 mg T enanthate/month for 2 yr and 7 months; it was discontinued 7 weeks before the in GnRH study began. At its start (July 1984) the subject's testis size was 7 mL, and he had azoospermia, low serum LH and FSH levels, and a serum T of 74 ng/dL (2.6 nmol/L). GnRH was administered in a dose of 200 micrograms (20-120 ng/kg were absorbed into the circulation) every 2 h, seven to nine times a day, between 0700 and 2400 h for 242 days. After 12 days of treatment, serum T had increased to 519 ng/dL (18.0 nmol/L). After 70 days, the patient's sperm count was 11.5 million/mL (4.5 mL ejaculate volume; 70% motility; 36% normal morphology); on day 185, sperm count was 31 million/mL (4 mL ejaculate volume; 54% motility; 36% normal morphology). His spouse conceived on day 162 and delivered a fullterm daughter 265 days later. The probability of paternity was 99.9994%. Our results suggest that induction and maintenance of spermatogenesis as well as fertility in hypothalamic hypogonadism can be achieved with in GnRH therapy if pituitary and testicular function are intact. Spermatogenesis induced by in GnRH has the same quality as spermatogenesis induced by hCG/human menopausal gonadotropin therapy. Patient compliance is probably the most important factor for the success of in GnRH therapy.

Adult↗

[Effect of liuwei dihuang decoction and its additives on boosting spermatogenesis in spermatogenesis obstruction rat].

OBJECTIVE: To study the effect of Liuwei Dihuang Decoction (LDD) and its additives on boosting the spermatogenesis in spermatogenesis obstruction rat. METHOD: The model of spermatogenesis obstruction of rat was made with gossypol acetate. Boosting spermatogenesis of LDD and its additives was studied by observing the number and quality of sperm. RESULT: The sperm quantity of LDD and its additives in treated group is significantly different from model group, and higher than that of positive group. The sperm quality of treated group is better than that of model group. CONCLUSION: LDD and its additives could rise the quantity and quality of spermatogenesis obstruction rat.

Animals↗

[Spermatogenesis in old age--nuclear DNA determination by flow cytophotometry in testicular samples of older men for the quantification of spermatogenesis].

The flow cytometric determination of the nuclear DNA content of testicular samples permits a fast and reliable quantification of spermatogenesis. 70 testicular samples from men over 50 years of age were analysed with this method. 60% of the samples showed a distinct reduction of spermatogenesis. Only three men showed a nonreduced spermatogenesis in both testes. Comparing the results of the measurements of both testes, in nearly half of the testes pairs a reduction of the germ cell number below two thirds of the better side was striking. In one patient, a Leydig cell tumor was detected by chance by an aneuploidy.

Aged↗

Spermatogenesis revisited. III. The course of spermatogenesis in a male-sterile pink-eyed mutant type in the mouse.

Male mice homozygous for the recessive p-locus allele ps are sterile. Spermatogenesis is normal through the completion of meiosis, but is abnormal from the Golgi phase of spermiogenesis on. During acrosome formation various abnormalities appear, ranging from atypical Golgiacrosome complexes to multiple acrosome "implantation" sites on the spermatid nuclei. In many developing acrosomal caps the distribution of acrosomal material is irregular. During the nuclear elongation phase, bundles of microtubules oriented parallel to the manchette have been seen lying in cylindrical invaginations of some spermatid nuclei. In later spermatids, chromatin condensation appears to proceed normally but may be unduly delayed in reaching completion. These various perturbations give rise to a wide spectrum of abnormal spermatozoa ranging from spermatozoa with heads of near-normal morphology to highly bizarre heads which have lost their chromatin. Sperm flagellar ultrastructure is normal and all sperm tails; even those devoid of recognizable heads, are highly motile. These findings support the view that the development of the sperm head is under the control of a group of genes distinct from those mediating events involved in flagella development.

Acrosome↗

Hormonal regulation of spermatogenesis in the hypophysectomized rat: FSH maintenance of cellular viability during pubertal spermatogenesis.

The potential for follicle-stimulating hormone (FSH) to promote germ-cell survival and the cellular sites of FSH action were studied using a gonadally maturing (pubertal), hypophysectomized (Hx) rat model in which residual testosterone (T) activity was blocked by injections of an androgen-receptor antagonist, flutamide. Recombinant human FSH was given to androgen-deprived and androgen-blocked male rats at 27 days of age to determine maintenance of individual germ-cell types at 35 days of age. Follicle-stimulating hormone significantly increased testis weights and tubular diameters as compared with Hx and Hx-flutamide controls, although testis weights in FSH-treated animals were significantly lower than in pituitary-intact animals. Morphometric assays to determine ratios of germ cells to Sertoli cells and to determine the number of germ cells present per hour of development showed that the population of type A spermatogonia in the early stages of the cycle was not responsive to FSH. Follicle-stimulating hormone had a marked ability to maintain cell viability in the rapid, successive divisions that begin in the latter part of the cycle and that continue through the next cycle (i.e., from type A1 to A4 and from intermediate spermatogonia to type B spermatogonia to preleptotene spermatocytes to leptotene/zygotene spermatocytes to young pachytene spermatocytes). The data also suggest T responsiveness of these cell types since the Hx-FSH-flutamide group showed lower cell viability at the aforementioned steps when compared with the Hx-FSH group. Too few cell types were present at subsequent phases of spermatogenesis to allow a sensitive determination of FSH activity in the maintenance of cell viability. The data show the potential of FSH in the absence or relative absence of T activity to maintain cell viability. These data support the concept of overlapping and synergistic (or additive) effects of T and FSH in the immature rat and identify the cellular sites of FSH action.

Androgen Antagonists↗

An ultrastructural study of plant spermatogenesis. Spermatogenesis in Nitella.

Spermatogenesis in the charophyte Nitella has been followed in antheridia prepared for light and electron microscopy. The antheridial filament cells contain paired centrioles which are similar in structure and behavior to the centrioles of animal cells. In the early spermatid, the centrioles undergo an initial elongation at their distal ends and become joined by a spindle-shaped fibrous connection. At the same time, their proximal ends are closely associated with the development of a layer of juxtaposed microtubules which will form the microtubular sheath. The architectural arrangement of these microtubules suggests that they constitute a cytoskeletal system, forming a framework along which the mitochondria and plastids become aligned and along which the nucleus undergoes extensive elongation and differentiation. The microtubular sheath persists in the mature sperm. During mid-spermatid stages, the centrioles give rise to the flagella and concomitantly undergo differentiation to become the basal bodies. The Golgi apparatus goes through a period of intensive activity during mid-spermatid stages, then decreases in organization until it can no longer be detected in the late spermatid. An attempt is made to compare similarities between plant and animal spermiogenesis.

Cell Differentiation↗

Spermatogenesis in XY, XYSxra and XOSxra mice: a quantitative analysis of spermatogenesis throughout puberty.

Adult XYSxra mice exhibit varying degrees of spermatogenic deficiency but are usually fertile, while XOSxra mice have severe spermatogenic failure and are always sterile. The present quantitative spermatogenic analysis documents when these anomalies first appear during puberty. The results demonstrate that in XYSxra mice there was increased degeneration of pachytene spermatocytes and, to a lesser extent, meiotic metaphase stages. On average, there were only one-half the number of spermatids compared with the XY controls. The defect in XOSxra mice appeared a little later, with an almost complete arrest and degeneration during the meiotic metaphases, so that the number of spermatids produced was only 3% of the control value. These results are discussed in relation to an hypothesis that links sex chromosome univalence during meiotic prophase with spermatogenic failure.

Animals↗

Genetic analysis of mammalian spermatogenesis: use of the t complex in the mouse in studies of spermatogenesis and sperm function.

Our observations suggest that sperm populations from the caudae epididymides of tw32/+ mice undergo hyperactivation in vitro sooner and to a much greater extent than do sperm populations from congenic +/+ mice: (1) epididymal tw32/+ sperm populations become significantly less progressive in vitro than do +/+ sperm populations; (2) low (0.1 mM) levels of Ca2+ prevent this loss of progressiveness; (3) epididymal tw32/+ sperm populations have trajectories and progressiveness values similar to both +/+ and tw32/+ oviductal sperm populations; (4) an inhibitor of capacitation inhibits the loss of progressiveness. This divergence from normal motility may be the result of expression of one of the factors involved in transmission distortion of the t complex.

Animals↗