Effects of steroid hormones on the differentiation of the catecholamine storing cells of the paracervical ganglion of the rat uterus

Zusammenfassung In der Lamina propria menschlicher Hodenkanälchen wurden spezialisierte Fibroblasten beobachtet. Die Zellen sind durch Bündel parallel geordneter Plasmafilamente gekennzeichnet, deren Durchmesser rund 80 Å beträgt. Die Filamentbündel verlaufen parallel zur Oberfläche der lamellär ausgebreiteten Zellen und inserieren in elektronendichtem, granulärem Material, das der Innenseite der Zellmembran anliegt. Es wird angenommen, daß dieses Fibrillensystem kontraktil ist; die dichtere oder lockerere Vernetzung der Filamente innerhalb der Bündel würde dem kontrahierten oder erschlafften Zustand der Zellen entsprechen. Die beschriebenen spezialisierten Fibroblasten sollten der Gruppe der Myofibroblasten zugeordnet werden (Gabbiani, Ryan und Majno, 1971).

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Contractile fibroblasts (myofibroblasts) in the lamina propria of human seminiferous tubules

Summary A special type of fibroblast is observed in the connective tissue of seminiferous tubules in human testes. These cells are characterized by a fibrillar system consisting of parallel arranged cytoplasmic filaments. The filaments have a mean diameter of 80 Å. Bundles of filaments run parallel to the surface of the flattened cells. The filaments insert in a dense, granular material which is connected with the cell membrane. This fibrillar system is thought to be contractile; the dense or more loose texture of the filaments within the bundles may correspond to the contracted or relaxed state of the cell. The specialized fibroblasts described are supposed to belong to the group of myofibroblasts (Gabbiani, Ryan and Majno, 1971).

     

Effect of dietary fish oil on mouse testosterone level and the distribution of eicosapentaenoic acid-containing phosphatidylcholine in testicular interstitium

Low levels of serum testosterone are characteristically associated with diabetes, coronary atherosclerosis, obstructive sleep apnea, rheumatoid arthritis, and chronic obstructive pulmonary disease. Testosterone replacement therapy is effective against many of these disorders, indicating the importance of maintaining a healthy testosterone level. In this study, we investigated the effects of fish oil on murine testosterone metabolism and analyzed the dynamics of relevant lipids in testes by matrix-assisted laser desorption ionization mass spectrometry imaging. Testosterone was upregulated in mice that received fish oil. In the testicular interstitium, eicosapentaenoic acid-containing phosphatidylcholine was distributed characteristically. These data suggest that eicosapentaenoic acid is involved in testosterone metabolism.     

Ethylene dimethane sulfonate (EDS) ablation of Leydig cells in adult rat depletes testosterone resulting in epididymal sperm granuloma: Testosterone replacement prevents granuloma formation

Sperm granuloma may develop in the epididymis following vasectomy or chemical insults. Inflammation due to sperm granuloma causes abdominal and scrotal pain. Prolonged and persistent inflammation in the epididymis due to sperm granuloma may lead to infertility. Extravasation of germ cells into the interstitium of epididymis following damage of the epididymal epithelium is one of the primary reasons for sperm granuloma-associated pathology. Since testosterone is vital for the maintenance of epididymal epithelium, we investigated the pathology of sperm granuloma and its relationship with testosterone. Adult rats were treated with a Leydig cell-specific toxicant ethylene dimethane sulfonate (EDS) to eliminate testosterone. At 7 days post-EDS, disrupted epididymal epithelium and sperm granuloma were observed in the caput epididymis. Sperm granuloma and caput were collagen-filled indicating fibrosis. Numerous round apoptotic cells were localized inside the caput lumen and dispersed through the sperm granuloma. Tnp1 (round spermatid marker) was significantly higher in the epididymis of the EDS-treated group compared to controls suggesting the apoptotic cells were round spermatids. Increases in CD68⁺ macrophages and T cells (CD4 and CD8) support an inflammatory immune infiltration in post-EDS epididymis. However, testosterone replacement following EDS prevented the sperm granuloma-associated pathology. We suggest that the immune response in the sperm granuloma may be due to the increased numbers of apoptotic round spermatids or other testicular tissue components that may be released, in addition to the regression of epididymal epithelium due to testosterone loss. Thus, testosterone replacement prevents EDS-induced sperm granuloma and ameliorates sperm granuloma-associated pathology.     

Study in vitro of the phagocytic function of Sertoli cells in the rat

Summary Aspects of the interaction between residual bodies/cytoplasts from elongated spermatids (RB/CES) and Sertoli cells were studied in vitro. Highly enriched Sertoli cells (91%; experiment A), very highly enriched Sertoli cells (>96%; experiment B), as well as peritubular cells were isolated from testes of 20-day-old rats by means of hypotonic treatment. Isolated Sertoli cells and peritubular cells were also prepared from 45-day-old rats (experiment C). RB/CES were isolated by centrifugal elutriation from testes of rats aged 90–120 days. The kinetics of adhesion of RB/CES to Sertoli cells were similar in all experiments. FSH accelerated binding of RB/CES but markedly reduced the number of RB/CES phagocytosed. Co-culture of the highly enriched Sertoli cells from experiments A and C with isolated peritubular cells did not change the kinetics of adhesion of RB/CES. However, when the contamination of Sertoli cells by peritubular cells was at a minimum (experiment B), addition of peritubular cells induced a slight but significant stimulation of the binding of RB/CES. Transmission electron microscopy revealed the following events within 24 h of co-culture: adhesion of the RB/CES to microvilli of Sertoli cells; internalization of RB/CES; lysis of the membrane of RB/CES; total digestion. Therefore, FSH and peritubular cells modulate the interaction in vitro between Sertoli cells and RB/CES, and the different steps of residual body disposal can be reproduced in co-culture. The co-culture model described in this study provides a useful system for the study of phagocytic activity by Sertoli cells.     

The spatio-temporal partitioning of sperm by males of the prospermatogenic parasitoid Nasonia vitripennis is in line with its gregarious lifestyle

Male fitness depends on the number of lifetime progeny of their mates and could be constrained by the chance of finding a mate, lifespan and temporal patterns of sperm production and allocation. Here, we used the parasitic wasp Nasonia vitripennis with a two-week lifespan and a gregarious lifestyle, to analyze how the reproductive system is organized to allocate spermatozoa over consecutive matings. Results show that spermatogenesis is synchronized and completed one day before emergence so that males emerge with a full sperm complement. We also found a regulation of spermatozoa transfer between testis and seminal vesicles that allows males to partition small ejaculates over multiple matings. Overall, this study shows that for N. vitripennis, male fertilization potential is determined (1) at the pupal stage, when spermatogenesis takes place to generate a complete life-long stock, (2) on emergence, when transport of spermatozoa from testes to seminal vesicles is initiated and (3) in adulthood, during which spermatozoa are partitioned over successive copulations. Such life history-traits are consistent with the gregarious lifestyle of N. vitripennis.     

The beneficial role of exercise in mitigating doxorubicin-induced Mitochondrionopathy

Doxorubicin (DOX) is a widely used antineoplastic agent for a wide range of cancers, including hematological malignancies, soft tissue sarcomas and solid tumors. However, DOX exhibits a dose-related toxicity that results in life-threatening cardiomyopathy. In addition to the heart, there is evidence that DOX toxicity extends to other organs. This general toxicity seems to be related to mitochondrial network structural, molecular and functional impairments. Several countermeasures for these negative effects have been proposed, being physical exercise, not only one of the most effective non-pharmacologic strategy but also widely recommended as booster against cancer-related fatigue.It is widely accepted that mitochondria are critical sensors of tissue functionality, both modulated by DOX and exercise. Therefore, this review focuses on the current understanding of the mitochondrial-mediated mechanisms underlying the protective effect of exercise against DOX-induced toxicity, not only limited to the cardiac tissue, but also in other tissues such as skeletal muscle, liver and brain. We here analyze recent developments regarding the beneficial effects of exercise targeting mitochondrial responsive phenotypes against redox changes, mitochondrial bioenergetics, apoptotic, dynamics and quality control signalling affected by DOX treatment.     

Evaluation of mathematical models to describe testicular growth in Blackbelly ram lambs

The primary objective was to compare various mathematical models to describe scrotal circumference (SC) and paired testis volume development in Blackbelly ram lambs. The study was conducted in the state of Querétaro, México (20° 43' N, 100° 15' W). Spring-born Blackbelly ram lambs (n = 41) were housed outdoors and fed alfalfa hay and concentrate. Body weight, SC, and testis length, diameter, and volume were recorded every 2 wk from 24 to 172 d of age (June 18 to November 3). The following mathematical functions were used to model SC-age and testis volume-age relationship: Von Bertalanffy, Brody, Gompertz, Logistic, and Richards. The suitability of the models was evaluated based on parameter values and standard errors, residual mean square, the coefficient of determination (R²), and the average prediction error (APE). All models, except for Brody's, had good fit to SC (R² > 0.98) and testis volume (R² > 0.95), and produced similar growth curves in the range of ages studied. The logistic model predicted SC at maturity quite well, 33.6 ± 0.6 cm as compared with 33.9 ± 0.5 cm observed in adult animals; all models had APE's smaller than ±7% between 56 and 168 d of age. The Bertalanffy model predicted testis volume at maturity quite well, 513 ± 22 cm³ as compared with 488 ± 20 cm³ calculated for adult animals. The logistic model had a good fit to testis volume during the period of study, but underestimated the volume at maturity by 28%. All models, except for Brody's, had APE's smaller than ±14% between 98 and 168 d of age. The logistic and Bertalanffy models predicted the inflection point for SC at 83 and 59 d of age, and testis volume at 116 and 109 d of age, respectively. In conclusion, all models, except for Brody's, had good fit to actual SC and testis volume data in the range of age evaluated, whereas the logistic and Bertalanffy's models made the best predictions for adult SC and testis volume, respectively.     

Normal fertility in male mice lacking ADAM32 with testis-specific expression

The a disintegrin and metalloprotease (ADAM) family proteins comprise a group of membrane-anchored proteins. ADAM32 is expressed specifically in testis and is closely related phylogenetically to ADAM2 and ADAM3, which are known to be critical for fertilization in mice. To assess the biological role of ADAM32, we analyzed Adam32-mutant mice. We found that male mice lacking ADAM32 have normal fertility, testicular integrity, and sperm characteristics. ADAM32 was found to exist at lower levels than ADAM2 and ADAM3 in wild-type testis and sperm, respectively. The present study demonstrates that ADAM32 is dispensable for fertility and appears to be functionally unrelated to ADAM2 and ADAM3 in mice.     

Effect of thyroidectomy on testicular enzymes of the pyruvate/malate cycle involved in lipogenesis

The specific activities of testicular enzymes of the pyruvate/malate cycle involved in lipogenesis after thyroidectomy and thyroxine replacement were studied in prepubertal, pubertal and adult rats. Thyroidectomy induced testicular ATP citrate-lyase, malate dehydrogenase and malic enzyme activities and inhibited isocitrate dehydrogenase (NADP⁺) activity. Thyroxine treatment on thyroidectomized animals reverted all enzyme activities to normal. The result suggests that thyroid hormones have a differential effects on testicular enzymes of the pyruvate/malate cycle involved in lipogenesis.