The annual testicular cycle in an equatorial colony of lesser rock hyrax, Heterohyrax brucei

1979 ◽  
Vol 206 (1163) ◽  
pp. 183-189 ◽  
Keyword(s):  
Annual Cycle ◽  
Leydig Cells ◽  
Seminal Vesicles ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Adult Males ◽  
Sperm Production ◽  
Rock Hyrax ◽  
Germinal Cells ◽  
Caput Epididymidis

Adult males from a colony of lesser rock hyrax found near the equator in Kenya exhibited an annual cycle of testicular activity characterized by intense spermatogenesis and elevated androgen status from May to July. Average masses of testes and seminal vesicles taken in these months were almost fourfold greater than those from September to January. During the months of peak testicular activity average diameters of Leydig cells and seminiferous tubules were increased by approximately one half and total tubule length was doubled, compared with values for the quiescent months. Variable testicular development occurred during transitional intervals preceding and following peak testicular activity. From February to April thickening of the seminiferous epithelium and appearance of spermatozoa in the caput epididymidis signalled re-establishment of sperm production. In August shedding of germinal cells from the epithelium heralded impending failure of spermatogenesis. Evidence of an annual testicular cycle contradicted the prevalent belief that equatorial hyrax breed all year and suggested that the testicular cycle is a conservative element of hyracoid reproductive strategy.

scholarly journals Morphometry and histomorphometry of the testis in crossbred pigs fed diets with different protein levels

2013 ◽  
Vol 65 (5) ◽  
pp. 1329-1338
Author(s):  
R.M.B. Valença ◽  
V.A. Silva Junior ◽  
L.P.C. Araújo ◽  
J.C. Reis ◽  
M.M.P. Guerra ◽  
...  
Keyword(s):  
Protein Content ◽  
Sertoli Cell ◽  
Leydig Cells ◽  
Crude Protein ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Sperm Production ◽  
Stages Of Development ◽  
Protein Levels ◽  
Crossbred Pigs

Aiming to evaluate the effect of the diet protein content on testicular parameters in pigs, 21 non-gelded male Dalland pigs were used and randomly divided into three groups. Males belonging to groups G2 and G3 received a diet with crude protein levels of 15% below and above, respectively, in relation to G1 (control). At 210 days of age, animals were castrated, and testis and epididymis were collected for morphometric and histomorphometry analyses. No difference was observed in relation to the total length of seminiferous tubules (G1=3239.9±333,3m; G2=2989.4±171,7m and G3=3059.5±254.9m), population of Sertoli cell (G1=4.7±0.5x10(9); G2=4.3±0.3x10(9) and G3=4.7±0.5x10(9)), population (G1=31.6±5.58x10(9); G2=27.3±4.0x10(9) and G3=26.4±3.9x10(9)) and volume of Leydig cells (G1=1289.3±182.6µm³; G2=1179.1±85.4µm³ and G3=1133.3±37.8µm³) and sperm production (G1=5.9±0.9x10(9); G2=5.6±0.6x10(9) and G3=5.1±0.3x10(9)). Protein levels were sufficient to maintain spermatogenesis in different experimental groups. It can be concluded that the magnitude of variation in levels of protein used in different stages of development was not sufficient to promote significant changes in testicular development and spermatogenesis process in adult animals.

scholarly journals Expression of steroidogenic enzymes during equine testicular development

Reproduction ◽  
2011 ◽  
Vol 141 (6) ◽  
pp. 841-848 ◽  
Author(s):  
J Almeida ◽  
A J Conley ◽  
L Mathewson ◽  
B A Ball
Keyword(s):  
Mrna Expression ◽  
Leydig Cells ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Steroidogenic Enzymes ◽  
Real Time Quantitative Pcr ◽  
Estrogen Production ◽  
Estrogen Synthesis ◽  
Small Clusters ◽  
Gene Mrna

In the mammalian testis, Leydig cells are primarily responsible for steroidogenesis. In adult stallions, the major endocrine products of Leydig cells include testosterone and estrogens. 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase (3βHSD) and 17α-hydroxylase/17,20-lyase (P450c17) are two key steroidogenic enzymes that regulate testosterone synthesis. Androgens produced by P450c17 serve as substrate for estrogen synthesis. The aim of this study was to investigate localization of the steroidogenic enzymes P450c17, 3βHSD, and P450arom and to determine changes in expression during development in the prepubertal, postpubertal, and adult equine testis based upon immunohistochemistry (IHC) and real-time quantitative PCR. Based on IHC, 3βHSD immunolabeling was observed within seminiferous tubules of prepubertal testes and decreased after puberty. On the other hand, immunolabeling of 3βHSD was very weak or absent in immature Leydig cells of prepubertal testes and increased after puberty. HSD3B1 (3βHSD gene) mRNA expression was higher in adult testes compared with prepubertal (P=0.0001) and postpubertal testes (P=0.0041). P450c17 immunolabeling was observed in small clusters of immature Leydig cells in prepubertal testes and increased after puberty. CYP17 (P450c17 gene) mRNA expression was higher in adult testes compared with prepubertal (P=0.030) and postpubertal testes (P=0.0318). A weak P450arom immunolabel was observed in immature Leydig cells of prepubertal testes and increased after puberty. Similarly, CYP19 (P450arom gene) mRNA expression was higher in adult testes compared with prepubertal (P=0.0001) and postpubertal (P=0.0001) testes. In conclusion, Leydig cells are the primary cell type responsible for androgen and estrogen production in the equine testis.

Increase in the Glycogen Content of the Leydig Cells of the Squirrel Monkey, Saimiri scireus, Induced by Human Chorionic Gonadotrophin

1974 ◽  
Vol 32 ◽  
pp. 134-135
Author(s):  
Lincoln J. Bank ◽  
Oscar W. Davidson ◽  
Alberto C. Seiguer
Keyword(s):  
Squirrel Monkey ◽  
Breeding Season ◽  
Leydig Cells ◽  
Glycogen Content ◽  
Squirrel Monkeys ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Seminiferous Tubules ◽  
Testicular Regression ◽  
Germinal Cells

It has been reported that during the non-breeding season, although the testes of squirrel monkeys decrease in size and the seminiferous tubules appear depleted from mature forms of germinal cells, the Leydig cells exhibit histological and ultrastructural features which appear to be similar in most respects to those found in active hormone secreting cells of normal, non-seasonal adult mammals (Belt and Cavazos, 1971). The present study was undertaken to determine the effects of Human Chorionic Gonadotrophin (HCG) on the ultrastructure of the Leydig cells in the testis of the squirrel monkey, saimiri scireus, during the season of testicular regression.

Suppression of spermatogenesis by exogenous testosterone

2020 ◽  
Vol 26 ◽  
Author(s):  
Ferdinando Fusco ◽  
Paolo Verze ◽  
Marco Capece ◽  
Luigi Napolitano
Keyword(s):  
Male Fertility ◽  
Leydig Cells ◽  
Sperm Count ◽  
Sperm Concentration ◽  
Seminiferous Tubules ◽  
Sperm Production ◽  
Long Term Effects ◽  
Fertility Status ◽  
Normal Spermatogenesis

: Sperm production starts from puberty in the seminiferous tubules providing for testosterone production by the Leydig cells taking place in the interstice of the testicles. Normal spermatogenesis depends on specific signalling from the hypothalamic-pituitary-gonadal axis. GnRH, FSH and LH are the main hormones involved in the production and maturation of spermatozoa. Exogenous administration of androgens influences the hypothalamic-pituitary-gonadal axis with negative feedback that may lead to partial or complete cessation of spermatogenesis by decreasing FSH and LH. Despite the fact that many trials have confirmed that exogenous testosterone affects male fertility status, evidence regarding the long-term effects of treatment is conflicting. Regarding this aspect, many studies have confirmed a return to baseline sperm concentration after testosterone treatment discontinuation, however none of them can specify how long recovery will take nor whether the sperm count is sufficient for fertility.

Testicular Degeneration and Necrosis Induced by Dietary Cobalt

1985 ◽  
Vol 22 (6) ◽  
pp. 610-616 ◽  
Author(s):  
D. E. Corrier ◽  
H. H. Mollenhauer ◽  
D. E. Clark ◽  
M. F. Hare ◽  
M. H. Elissalde
Keyword(s):  
Sertoli Cells ◽  
Leydig Cells ◽  
Giant Cells ◽  
Seminal Vesicles ◽  
Germinal Epithelium ◽  
Seminiferous Tubules ◽  
Multinucleated Giant Cells ◽  
Necrotic Debris ◽  
Testicular Degeneration

Dietary cobalt (265 ppm Co) induced polycythemia and consistent degenerative and necrotic lesions in the seminiferous tubules of rats. Cyanosis and engorgement of testicular vasculature on day 35 and thereafter was followed on day 70 by degenerative and necrotic changes in the germinal epithelium and Sertoli cells. Spermatogonia, primary spermatocytes and round spermatids were markedly affected, while elongated spermatids, spermatozoa, and Sertoli cells were more resistant. Damaged tubules, often present side by side with normal tubules, contained multinucleated giant cells composed of degenerated and necrotic spermatocytes and/or spermatids, sloughed germinal and Sertoli cells, and calcified necrotic debris. Necrotic tubules were frequently collapsed and devoid of epithelium except for occasional spermatogonia and surviving Sertoli cells. Lesions were not observed in the Leydig cells, cauda epididymis or seminal vesicles.

Duration of spermatogenesis and daily sperm production in the rodent Proechimys guyannensis

Zygote ◽  
2016 ◽  
Vol 24 (5) ◽  
pp. 783-793 ◽  
Author(s):  
Nathália L.M. Lara ◽  
Ivan C. Santos ◽  
Guilherme M.J. Costa ◽  
Dirceu A. Cordeiro-Junior ◽  
Antônio C. G. Almeida ◽  
...  
Keyword(s):  
Leydig Cells ◽  
Gonadosomatic Index ◽  
Cell Types ◽  
Seminiferous Tubules ◽  
Testis Weight ◽  
Sperm Production ◽  
The Mean ◽  
Neotropical Rodent ◽  
Very High ◽  
Daily Sperm Production

SummaryThe spiny rat (Proechimys guyannensis) is a neotropical rodent that is used in biomedical research, particularly research related to chronic resistance to epilepsy and infectious diseases. To our knowledge, there are few reports concerning the reproductive biology of this species. Therefore, besides providing basic biometric and morphometric data, in the present study we investigated testis function and spermatogenesis in adult spiny rats. The mean testis weight and gonadosomatic index obtained were 1.63 ± 0.2 g and 1.15 ± 0.1% respectively. Based on the development of the acrosomic system, 12 stages of the seminiferous epithelium cycle were characterized. Stages VI and VII presented the highest frequencies (~17–19%), whilst stages II to V showed the lowest frequencies (~2–4%). The most advanced germ cell types labelled at 1 h or 20 days after BrdU injections were respectively preleptotene/leptotene spermatocytes at stage VII and elongated spermatids at stage III. The mean duration of one cycle was 7.5 ± 0.01 days and the entire spermatogenic process lasted 33.7 ± 0.06 days (~4.5 cycles). The seminiferous tubules (ST) occupied ~96 ± 1% of the testis parenchyma, whereas Leydig cells comprised only 1.5 ± 0.4%. The number of Sertoli cells (SC) per testis gram and the SC efficiency (spermatids/SC) were respectively 78 × 106 ± 11 × 106 and 7.9 ± 1. The daily sperm production per testis gram (spermatogenic efficiency; daily sperm production (DSP)/g/testis) was 78 × 106 ± 8 × 106. To our knowledge, this spermatogenic efficiency is among the highest found for mammals investigated to date and is probably related to the very short duration of spermatogenesis and the very high ST percentage and SC number obtained for this species.

Inhibition of testicular and somatic development after treatment of the postnatal rat with the Leydig cell cytotoxic ethylene dimethanesulphonate

1988 ◽  
Vol 119 (3) ◽  
pp. 467-NP ◽  
Author(s):  
I. D. Morris ◽  
R. G. Lendon ◽  
A. Zaidi
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Serum Testosterone ◽  
Male Rats ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Interstitial Tissue ◽  
Somatic Development ◽  
Serum Lh ◽  
Loss Of Weight

ABSTRACT The Leydig cell cytotoxic ethylene dimethanesulphonate (EDS) was administered s.c. daily (50 mg/kg) to male rats aged 5–16 days. Apart from loss of weight and that the eyelids unfused earlier, no gross toxicity was observed during treatment. On day 17 testis weights, serum testosterone concentrations, testicular serum testosterone content and 125I-labelled human chorionic gonadotrophin (hCG) binding to testicular homogenates were reduced. Serum LH and FSH concentrations were elevated. The testes did not recover from EDS treatment and at 63 and 120 days were minute (<2% of control), and the prostate and seminal vesicles were small although not completely atrophied. In addition, body weights were substantially reduced. Serum and testicular testosterone and 125I-labelled hCG binding to testicular homogenates were reduced but not absent. Serum LH and FSH concentrations were increased. Light microscopy of the adult testes showed that EDS treatment inhibited the development of the seminiferous tubules. Most of the tubules were devoid of germ cells and Sertoli cells were rare. Occasionally tubules also contained spermatogonia and spermatocytes but no signs of spermiogenesis. The testes were composed mainly of closely packed interstitial tissue with no lymphatic space. The interstitial cells resembled Leydig cells and stained for 3β-hydroxysteroid dehydrogenase. Histochemically identified Leydig cells were absent during treatment but reappeared when treatment was withdrawn. Testicular Leydig cell numbers were only 7% of control values in the 63-day-old EDS-treated rat. The effect on the testis of EDS treatment administered at a crucial time of testicular development may be explained by withdrawal of androgen; however, the systemic effects indicate non-specific toxicity so any explanation of these changes must be viewed with caution. J. Endocr. (1988) 119, 467–474

STUDIES ON A BOY WITH XXYY CHROMOSOME CONSTITUTION

PEDIATRICS ◽  
1965 ◽  
Vol 36 (1) ◽  
pp. 113-119
Author(s):  
Robert J. Schlegel ◽  
Manuel J. Aspillaga ◽  
Richard Neu ◽  
Lytt I. Gardner
Keyword(s):  
Leydig Cells ◽  
Chromosomal Abnormalities ◽  
Pulmonary Stenosis ◽  
Chromosome Complement ◽  
Testicular Biopsy ◽  
Seminiferous Tubules ◽  
Testicular Cells ◽  
Buccal Epithelial Cells ◽  
Sex Chromatin ◽  
Germinal Cells

The twelfth instance in a human of an XXYY chromosome complement is described in a 16-year-old boy. One hundred thirty-five metaphase plates from two leucocyte cultures and ten from testis and skin had a modal number of 48 chromosomes. Karyotyping demonstrated 2X-chromosomes 2Y-chromosomes, and 44 autosomes. Sex chromatin bodies were present in 23-28% of buccal epithelial cells and in testicular cells, and there were 17 drumsticks in 500 neutrophiles. Micro-orchidism and azoospermia were present. Testicular biopsy revealed diminution of germinal cells and hyalinization of seminiferous tubules, together with clumping of the Leydig cells. A small brain case (20.8 in. occipitofrontal circumference) and mental retardation (Stanford-Binet I. Q. 62) were found. He also had slight facial prognathism, webbing of the neck, and congenital infundibular pulmonary stenosis. There were no chromosomal abnormalities found in studies performed on his parents. Both the patient and many members of his immediate family had unusual dermatoglyphic findings, including low ridge counts and a high number of arches on the fingers.

Reproduction of the Spinifex Hopping Mouse (Notomys-Alexis) in the Natural-Environment

1992 ◽  
Vol 40 (1) ◽  
pp. 57 ◽  
Author(s):  
WG Breed
Keyword(s):  
Germ Cell ◽  
Cross Sections ◽  
Natural Environment ◽  
Reproductive Activity ◽  
Field Trips ◽  
Seminal Vesicles ◽  
Seminiferous Tubules ◽  
Corpora Lutea ◽  
Adult Males ◽  
Sexually Mature

Seven field trips to Curtin Springs Station, in the south of the Northern Territory (two in July and five in December-January), were carried out between July 1984 and January 1991 to investigate the reproductive activity of spinifex hopping mice in the natural environment. Gonadal activity was determined from most samples of animals collected. Pregnant animals were present on only one occasion (December 1988-January 1989), but two females collected in December 1985 had corpora lutea in their ovaries. Most adult males were, by contrast, sexually mature, as indicated by germ-cell associations in the seminiferous tubules, spermatozoa in the excurrent ducts, and secretion in the lumina of the ventral prostates and seminal vesicles. Nevertheless, the testes were invariably very small, 2-4 germ-cell associations were sometimes present in tubule cross-sections, epididymal spermatozoa were highly pleiomorphic and seminal vesicles minute. Such morphological traits are thus invariable features of the reproductive biology of males of this species.

Aromatase and 11β-hydroxysteroid dehydrogenase 2 localisation in the testes of pigs from birth to puberty linked to changes of hormone pattern and testicular morphology

2008 ◽  
Vol 20 (4) ◽  
pp. 505 ◽  
Author(s):  
A. Wagner ◽  
R. Claus
Keyword(s):  
Blood Plasma ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Blood Collection ◽  
Testicular Development ◽  
Post Mortem ◽  
Cell Numbers ◽  
Testicular Morphology

Oestrogens and glucocorticoids are important for spermatogenesis and are regulated via aromatase for oestradiol synthesis and 11β-hydroxysteroid dehydrogenase 2 (11β-HSD 2) as an inactivator of cortisol. In the present study postnatal changes of these two enzymes were monitored together with testicular development and hormone concentrations. Pigs were assigned to three periods: Weeks 0–5, Weeks 5–11 or Weeks 11–17. In Period 1, groups of four piglets were killed after each week. Blood plasma and testes were sampled immediately post mortem. For Periods 2 and 3, groups of six pigs were fitted with vein catheters for daily blood collection. Testes from all pigs were obtained after killing. Levels of testosterone, oestradiol, LH, FSH and cortisol were determined radioimmunologically. The 11β-HSD 2- and aromatase-expressing cells were stained immunocytochemically. All hormones were maximal 2 weeks after birth. A rise of LH, testosterone and oestradiol occurred again at Week 17. FSH and cortisol remained basal. Parallel to the first postnatal rise, the presence of aromatase and 11β-HSD 2 in Leydig cells increased, together with germ and Sertoli cell numbers. Expression was low from 3 to 5 weeks, was resumed after Week 5 and was maximal at Week 17. The amount of 11β-HSD 2 in germ cells was greatest at birth, decreased thereafter and was absent after Week 3.

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