Testosterone Prevents Cutaneous Ischemia and Necrosis in Males Through Complementary Estrogenic and Androgenic Actions

Exogenous Testosterone Replacement Therapy Is Associated with Increased Risk for Vascular Graft Infections Among Hypogonadal Men

BACKGROUND

Vascular graft infections (VGIs) are a major source of morbidity following vascular bypass surgery. Hypogonadal men may be at increased risk for impaired wound healing and infections, but it is unclear if testosterone replacement therapy (TRT) mitigates this risk. We designed this study to evaluate the relationship between hypogonadism and the use of testosterone replacement therapy (TRT) with subsequent risk for developing a VGI.

METHODS

We performed a retrospective analysis of claims in the MarketScan database identifying men greater than 18 years of age who underwent placement of a prosthetic graft in the peripheral arterial circulation from January 2009 to December 2020. Patients were stratified based on diagnosis of hypogonadism and use of TRT within 180 days before surgery. The primary outcome was VGI and the need for surgical excision. The association between hypogonadism and TRT use on risk of VGI was analyzed using Kaplan-Meier plots and multivariate Cox proportional hazards models.

RESULTS

We identified 18,312 men who underwent a prosthetic bypass graft procedure in the upper and lower extremity during the study period, of which 802 (5%) had diagnosis of hypogonadism. Among men with hypogonadism, 251 (31%) were receiving TRT. Patients on TRT were younger, more likely to be diabetic, and more likely develop a VGI during follow-up (14% vs. 8%; P < 0.001) that was in the lower extremity. At 5 years, freedom from VGI was significantly lower for hypogonadal men on TRT than patients not on TRT or without hypogonadism (Log rank P < 0.001). In Cox regression models adjusted for age, diabetes, obesity, smoking, corticosteroid use, and procedure type, hypogonadal men on TRT were at a significantly increased risk of graft infection (hazard ratio (HR):1.94, 95% confidence interval (CI):1.4-2.7; P < 0.001) compared to controls.

CONCLUSIONS

This study demonstrates TRT among hypogonadal men is associated with an increased risk of prosthetic VGIs. Temporary cessation of TRT should be considered for men undergoing prosthetic graft implants, particularly those in the lower extremity.

Seasonal changes in the scrotal skin histology in relation to thermoregulation and testosterone level in camel and buffalo bull

This study was conducted to compare the scrotal skin dynamics of camel and buffalo bulls regarding thermoregulation, season and testosterone. Scrotal skin and blood samples (n = 8 each) were collected during breeding (October to March) and non-breeding seasons (April to August). Tissue slides were prepared by the paraffin embedding technique followed by hematoxylin and eosin (H&E) staining and were analysed by ImageJ®. Relative humidity and temperature were recorded in different seasons to calculate the thermal humidity index (THI). Serum testosterone level was estimated through radioimmunoassay (RIA). The data were analysed by applying ANOVA, the THS test was used as a post-ANOVA interface and the correlation coefficient was also calculated among season, testosterone and skin parameters. The results showed that skin thickness, season and THI were negatively correlated with testosterone levels. In the neck, body and apex, the papillary layer was thicker in buffalo bull compared to camel bull during the breeding season; however, the reticular layer followed a reverse trend in the apex when THI was low. In the scrotal neck during the non-breeding season, hair follicle (HF) length and density were recorded high in camel bull compared to buffalo bull when THI was elevated. The density of HF followed the otherwise trend in the apex during the breeding season. The density of SG was found highest in all regions of camel bull as compared to buffalo bull and showed direct relation with THI. To conclude, this study delineates how the histo-dynamics of scrotal skin varies and accommodate itself with testosterone and THI over the different season in camel and buffalo.

Perioperative substitution testosterone therapy in patients with advanced head and neck squamous cell carcinoma

Testosterone replacement therapy is becoming more and more popular in men as "anti-aging medicine". Testosterone has beneficial effects on body mass and muscle gain, and much research has examined testosterone in palliative cancer therapy for oncology patients. In addition to direct effects on weight gain, testosterone improves mood and self-confidence, strength, libido, muscle mass, bone density, and cognitive functions and reduces the risk of cardiovascular disease. Lower testosterone levels are found in 65% of male patients with progressive tumors compared to only 6% of men in the general population. We hypothesize that perioperative substitution testosterone therapy (PSTT) together with a balanced diet, may be more effective than balanced diet alone in the overall treatment outcome of patients with head and neck squamous cell carcinomas. Therefore, PSTT in combination with a balanced diet should be considered as an additional tool for head and neck carcinoma treatment.

Testosterone replacement relieves ligature-induced periodontitis by mitigating inflammation, increasing pro-resolving markers and promoting angiogenesis in rats: A preclinical study

OBJECTIVES

This study aimed to evaluate the inflammatory profile as well as the resolution of inflammation in a ligature-induced periodontal inflammation in rats with depletion and/or supraphysiological testosterone replacement.

DESIGN

Sixty male rats (Holtzman) were used in the present study. Study groups were created as following: (1) Sham (no testicle removal); (2) Orchiectomy (OCX), 3) OCX + Testosterone (OCX + T); (4) Sham + Ligature (SH + L); (5) OCX+L; and 6) OCX + T + L. The surgeries were performed on day 1, and testosterone was administered weekly since day 1. On day 15, a cotton ligature was placed around the lower first molars and maintained for 15 days. Morphological changes in periodontal tissues were determined by histopathological analysis. Immunohistochemistry (factor VIII) and immunoenzymatic assay were performed to evaluate angiogenesis process and (pro- and anti-) inflammatory markers, respectively.

RESULTS

Ligature promoted a marked inflammatory gingival infiltrate and bone loss (P < 0.05). Supraphysiological testosterone treatment increased the percentage of blood vessels, extracellular matrix and fibroblasts in the presence and absence of periodontal inflammation (P < 0.05). A high dose of testosterone increased factor VIII+ blood vessels and IL-10 expression in inflamed gingival tissue, while PGE₂, LXA₄ and MPO were reduced as a result of supraphysiological testosterone administration (P < 0.05).

CONCLUSIONS

These results, in our experimental model, suggest that supraphysiological testosterone treatment stimulated gingival tissue repair during ligature-induced periodontitis, and it seems to be related to an anti-inflammatory and pro-resolutive mechanism resulting by the modulatory effect on PGE₂ and IL-10 related to an enhanced angiogenesis.

Estrogen Receptor and Vascular Aging

Cardiovascular diseases remain an age-related pathology in both men and women. These pathologies are 3-fold more frequent in men than in women before menopause, although this difference progressively decreases after menopause. The vasculoprotective role of estrogens are well established before menopause, but the consequences of their abrupt decline on the cardiovascular risk at menopause remain debated. In this review, we will attempt to summarize the main clinical and experimental studies reporting the protective effects of estrogens against cardiovascular diseases, with a particular focus on atherosclerosis, and the impact of aging and estrogen deprivation on their endothelial actions. The arterial actions of estrogens, but also part of that of androgens through their aromatization into estrogens, are mediated by the estrogen receptor (ER)α and ERβ. ERs belong to the nuclear receptor family and act by transcriptional regulation in the nucleus, but also exert non-genomic/extranuclear actions. Beside the decline of estrogens at menopause, abnormalities in the expression and/or function of ERs in the tissues, and particularly in arteries, could contribute to the failure of classic estrogens to protect arteries during aging. Finally, we will discuss how recent insights in the mechanisms of action of ERα could contribute to optimize the hormonal treatment of the menopause.

Supraphysiological testosterone supplementation improves granulation tissue maturation through angiogenesis in the early phase of a cutaneous wound healing model in rats

OBJECTIVE

The aim of this study was to evaluate the effects of both testosterone depletion and supraphysiological testosterone supplementation in the early phase of an animal cutaneous wound healing model in comparison with the physiological hormonal condition.

MATERIAL AND METHODS

Forty rats were distributed into the following four groups: Control, Orchiectomy (OCX), Durateston (Dura) and OCX+Dura. On day 1, the testicles were removed (OCX group) and the rats (Dura group) received a supraphysiological dose (250 mg/kg) of exogenous testosterone weekly. After 15 days a full-thickness excisional skin wound was created in all animals, which was healed by the second intention for 7 days. On day 22, the rats were euthanatized and the wounds were harvested for histopathological evaluation, immunohistochemistry analyses and multiplex immunoassay. One-way ANOVA and post-hoc Tukey tests were performed.

RESULTS

It was found that the supraphysiological testosterone level increased extracellular matrix deposition, promoted higher blood vessel formation and reduced wound contraction (p < 0.05). Additionally, it also stimulated PCNA-positive fibroblasts and KGF-positive cells (p < 0.05), while orchiectomy reduced the expression of IL-6 and TNF-α and increased VEGF and PDGF (p < 0.05) .

CONCLUSION

In conclusion, the results provide evidence that supraphysiological testosterone supplementation plays a positive role in the early phase of cutaneous wound healing, thus improving granulation tissue maturation through the enhancement of angiogenesis.

Perivascular Injections of Botulinum Toxin Type A Versus Low Concentration of Ethanol

BACKGROUND

This study aimed to investigate the effect of low concentration ethanol in increasing flap viability by perioperative perivascular application and compared it with that of botulinum toxin type A (BTX-A).

MATERIALS AND METHODS

Twenty-seven Wistar albino rats weighing 300-350 g were used in this study. The subjects were randomly divided into three equal groups: group E (ethanol, n = 9), group B (BTX-A, n = 9), and group S (saline, n = 9). In rats, the dorsal multi-territory perforator flap was elevated, and the agents were injected. In postoperative 1 wk, flap viability and vascular endothelial growth factor levels were evaluated. Also, blood flow, microvascular density, and inflammation degree of both choke zones were assessed.

RESULTS

The mean flap survival area and vascular endothelial growth factor level were significantly higher in group E than in group B and S (P < 0.001). Similarly, blood flow (first choke zone, P < 0.012, and second choke zone, P < 0.001) and microvascular density (first choke zone and second choke zone, P < 0.001) were found to be higher in Group E compared to Group B and S in the evaluation performed from both choke zones. Also, significant inflammation was detected in the ethanol group.

CONCLUSIONS

The positive effects of BTX-A on flap viability were achieved with a low concentration of ethanol. The fact that a low concentration of ethanol increases blood flow, angiogenesis, and flap viability more than BTX-A in the first postoperative week indicates that it can be an alternative agent for perioperative use.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

Male and Female Mice Exhibit Divergent Responses of the Cortical Vasculature to Traumatic Brain Injury

We previously reported that traumatic brain injuries (TBI) alter the cerebrovasculature near the injury site in rats, followed by revascularization over a 2-week period. Here, we tested our hypothesis that male and female adult mice have differential cerebrovascular responses following a moderate controlled cortical impact (CCI). Using in vivo magnetic resonance imaging (MRI), a new technique called vessel painting, and immunohistochemistry, we found no differences between males and females in lesion volume, neurodegeneration, blood-brain barrier (BBB) alteration, and microglia activation. However, females exhibited more astrocytic hypertrophy and heme-oxygenase-1 (HO-1) induction at 1 day post-injury (dpi), whereas males presented with increased endothelial activation and expression of β-catenin, shown to be involved in angiogenesis. At 7 dpi, we observed an increase in the number of vessels and an enhancement in vessel complexity in the injured cortex of males compared with females. Cerebrovasculature recovers differently after CCI, suggesting biological sex should be considered when designing new therapeutic agents.

Estrogen Effects on Wound Healing

Wound healing is a physiological process, involving three successive and overlapping phases—hemostasis/inflammation, proliferation, and remodeling—to maintain the integrity of skin after trauma, either by accident or by procedure. Any disruption or unbalanced distribution of these processes might result in abnormal wound healing. Many molecular and clinical data support the effects of estrogen on normal skin homeostasis and wound healing. Estrogen deficiency, for example in postmenopausal women, is detrimental to wound healing processes, notably inflammation and re-granulation, while exogenous estrogen treatment may reverse these effects. Understanding the role of estrogen on skin might provide further opportunities to develop estrogen-related therapy for assistance in wound healing.