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Background Infertility is a global concern in both humans and domestic animals, with male factors accounting for nearly half of all cases. Among male reproductive structures, the efferent ductules play a crucial but understudied role in fertility. These tubules connect the testis to the epididymis and are primarily responsible for luminal fluid reabsorption, a process essential for sperm concentration, maturation, and transport. This study aimed to provide a comparative morphological and histological characterization of the efferent ductules in four species—rats, bulls, stallions, and boars—focusing on regional variations (proximal, middle, and distal) and their potential functional implications. Results Gross dissection and histological evaluation revealed a columnar epithelium composed of ciliated and nonciliated cells in all species. Comparative analysis identified species-specific differences in connective tissue composition, smooth muscle thickness, and epithelial dimensions. Proximal regions generally exhibited larger lumen diameters and lower epithelial heights, whereas distal regions showed increased ciliary height and, in some species, a greater presence of cytoplasmic granules, suggesting enhanced secretory or absorptive activity prior to sperm entry into the epididymis. Boars exhibited a particularly thick smooth muscle layer and abundant granules in the distal region. Morphometric measurements supported these observations, demonstrating consistent patterns of structural variation across species. Conclusions The efferent ductules display complex, species-specific architecture and specialized regional features that likely contribute to their functional role in fluid reabsorption and sperm modification. These findings expand current knowledge of male reproductive morphology in domestic animals and highlight the need for further functional studies beyond rodent models to better understand fertility regulation in veterinary species.

Objective: To investigate whether the regular administration of blueberry extract and low-intensity resistance exercise training (RT), either alone or in combination, during the development of monocrotaline (MCT)-induced severe pulmonary arterial hypertension (PAH) in rats protect the left ventricle (LV) from redox dysregulation and pathological remodeling. Methods: Groups of seven male Wistar rats were formed for the experiment: sedentary control; sedentary hypertensive; sedentary hypertensive blueberry; exercise hypertensive; and exercise hypertensive blueberry. PAH was experimentally induced through a single intraperitoneal administration of MCT at a dose of 60 mg/kg. One day after injection, the blueberry groups started receiving a daily dose of blueberry extract (100 mg/kg) by gavage, while the exercise groups initiated a three-week program of RT (ladder climbing; 15 climbs carrying 60% of maximum load; one session/day; 5 times/week). Echocardiographic evaluations were conducted 23 days after injection, and the rats were euthanized the next day to harvest LV tissue. Results: Separately, blueberry extract and RT mitigated augments in pulmonary artery resistance, LV tissue redox dysregulation (i.e., increased PC levels) and detrimental remodeling (i.e., reduced inflammation), and reductions in ejection fraction (EF) and fractional shortening (FS) caused by PAH. The combination of treatments prevented reductions in EF and FS, along with the development of a D-shaped LV. Conclusions: blueberry extract and moderate-intensity resistance training administered during the development of MCT-induced severe PAH in rats prevented LV redox dysregulation and pathological remodeling, thereby preserving its function.

This study investigated whether previous resistance exercise training (RT) affects the progression of right ventricular dysfunction and remodeling in rats with severe pulmonary artery hypertension (PAH). Male Wistar rats were submitted to a RT protocol (i.e., ladder-climbing) for 8 weeks, while controls remained in cages without exercising. Then, exercised rats were randomly divided into trained monocrotaline discontinued (TMD), and trained monocrotaline continued (TMC) groups. Subsequently, they received a single monocrotaline injection (i.e., 60 mg/kg) and the TMD group stopped RT, while the TMC group exercised for an additional 6-week period. After euthanasia, right ventricle (RV) was dissected and processed for histological and single RV myocyte analyses. Previous RT increased physical effort tolerance, prevented pulmonary artery resistance augment (i.e., AT/ET) and mitigated the reduction in RV systolic function (i.e., TAPSE). RT also lessened impairments in single RV myocyte contractility and intracellular calcium transient (i.e., amplitude, and times to peak and relaxation) in the TMC group only. Moreover, RT inhibited adverse RV remodeling (i.e., hypertrophy and collagen deposition) in both trained groups. In conclusion, previous RT attenuates the progression of RV dysfunction and remodeling in rats with severe monocrotaline-induced PAH, being the extension of protective effects dependent on the exercise training continuity.

Pulmonary arterial hypertension (PAH) is a disease that affects millions of people worldwide. Besides the effects on the lungs and heart, PAH can affect other organs, including the liver, kidneys, brain, glands, and testis. This study aimed to evaluate the impact of PAH and physical resistance training (RT), a complementary treatment for hypertension, on epididymis morphology and function and sperm parameters. Wistar rats were divided into four experimental groups ( n  = 8/ group): sedentary control, sedentary PAH, RT control, and RT + PAH. PAH was induced using monocrotaline injections on Day 1 and 7 of the experiment. Sixteen rats from RT groups underwent RT training for 30 days, while rats from sedentary groups did not exercise. The epididymis was processed and analyzed using microscopic, biochemical, and functional approaches. Sperm were harvested from the cauda epididymis and evaluated for morphology and motility. Our results showed that PAH compromised the epididymis antioxidant defense system and reduced NO levels, leading to an imbalance in the organ's mineral content. These alterations affected the epididymis morphology and reduced the sperm transit time in the proximal epididymis, resulting in an increase in abnormal sperm morphology in the cauda region. Unfortunately, RT was not a good therapy against the PAH effect on the epididymis. PAH negatively affected epididymis functions with consequences to male gametes. Dysfunctions in the post-testicular environment may lead to male infertility due to the disturbance of spermatozoa fecundity. Graphical Abstract