Scrotal thermographic profile and seminal characteristics of Mangalarga Marchador stallions bred in the Atlantic Rainforest biome

ABSTRACT The objective of this study was to determine the scrotal thermographic profile and to verify the influence of temperature and humidity of the humid tropical climate on testicular temperature and seminal quality of Mangalarga Marchador stallions. The thermal profiles of the proximal, middle, and distal zones of the testicles and total surface temperature (TSTT) were recorded using an FLIR E60bx thermal imager. The average air temperature (°C) and relative humidity (%) were obtained 1, 5, 9, 33, and 66 days before semen collection and showed a mean value of 26.5±2.4 and 80.4±6.0 respectively. The scrotal surface temperature was close to 34°C and there was no variation with the age of the stallion, reproductive activity, and characteristics of the ejaculate (P>0.05). The only significant correlations obtained were between TSTT and minor defects (R = 0.41; P<0.05), between TSTT and total defects (R = 0.46; P<0.01), and between TSTT and percentage of morphologically normal sperm (R = -0.46; P<0.05). It was concluded that the Mangalarga Marchador stallions maintained the testicular temperature within favorable conditions for spermatogenesis, demonstrating the efficiency of testicular thermoregulation mechanisms in the Atlantic Forest biome.

Hemiscrotal agenesis with complete testicular descent in Van der Woude syndrome: a new phenotypic feature

Van der Woude syndrome (VWS) and popliteal pterygium syndrome (PPS) spectrum are due to genetic variants in the IRF6 which phenotypically has been known to manifest with midline defects such as cleft lip and palate in VWS and additional nail, limb and genital anomalies in PPS. We report a case of VWS with the previously unrecognised phenotypic feature of hemiscrotal agenesis. While bifid scrotum has been reported in the more severe PPS, neither VWS nor PPS have previously noted hemiscrotal agenesis as part of the phenotypic picture. Hemiscrotal agenesis without evidence of any genetic anomaly has only been reported four times in the literature to date with two of these being accompanied by complete testicular descent. Treatment options include topical androgen application and/or scrotoplasty to allow for adequate testicular thermoregulation and development to occur.

Testicular hyperthermia increases blood flow that maintains aerobic metabolism in rams

There is a paradigm that testicular hyperthermia fails to increase testicular blood flow and that an ensuing hypoxia impairs spermatogenesis. However, in our previous studies, decreases in normal and motile spermatozoa after testicular warming were neither prevented by concurrent hyperoxia nor replicated by hypoxia. The objective of the present study was to determine the effects of increasing testicular temperature on testicular blood flow and O2 delivery and uptake and to detect evidence of anaerobic metabolism. Under general anaesthesia, the testicular temperature of nine crossbred rams was sequentially maintained at ~33°C, 37°C and 40°C (±0.5°C; 45min per temperature). As testicular temperature increased from 33°C to 40°C there were increases in testicular blood flow (13.2±2.7 vs 17.7±3.2mLmin−1 per 100g of testes, mean±s.e.m.; P&lt;0.05), O2 extraction (31.2±5.0 vs 47.3±3.1%; P&lt;0.0001) and O2 consumption (0.35±0.04 vs 0.64±0.06mLmin−1 per 100g of testes; P&lt;0.0001). There was no evidence of anaerobic metabolism, based on a lack of change in lactate, pH, HCO3− and base excess. In conclusion, these data challenge the paradigm regarding scrotal–testicular thermoregulation, as acute testicular hyperthermia increased blood flow and tended to increase O2 delivery and uptake, with no indication of hypoxia or anaerobic metabolism.

The structure, morphometry and vascular perfusion of the testis in the rufous sengi (Elephantulus rufescens)

Introduction and Materials and Methods: Sengis are testicondid, monogamous afrotherian mammals. The testes, pattern of testicular blood vessels and anatomical disposition of caudal vena cava were examined macroscopically in the rufous sengi (Elephantulus rufescens). Testicular structure was further studied microscopically and its components quantified using stereology. Results: The testes were cylindrical in shape and located caudolateral to the kidneys. The testicular arteries branched from renal arteries, ran to the respective testicles without close association with other vessels, while the veins ran straight to the caudal vena cava without pampiniform plexus or intimate association with cognate arteries. There were two caudal vena cavae that united after receiving the renal veins. The seminiferous tubules were bound by a peritubular boundary tissue with a single layer of myoid cells while the interstitial tissue had polyhedral or elongate Leydig cells and connective tissue elements. The testicular volume was estimated at 0.089 ± 0.0031 cm3 with the seminiferous tubules (mean diameter = 210 ± 5.7 μm) constituting 89.4 ± 0.8% of its volume and tubulosomatic index of 0.38%. The interstitial tissue and tunica albuginea constituted 8.9 ± 0.81% and 1.7 ± 0.1% of the testis volume respectively. Conclusion: The testis exhibited general mammalian features while its vascular pattern was simple without indications of a role in testicular thermoregulation as is the case for other afrotherians. The investment of body mass in seminiferous tubules suggests a spermatogenic activity higher than expected in monogamous animals. The double caudal vena cava could be a result of retention of the left supracardinal vein to adulthood.