The effects of melatonin on the concentrations of inflammatory cytokines and proteins, serotonin, cortisol and melatonin in ovariohysterectomised female dogs.

BACKGROUND: Ovariohysterectomy (OHE) induces inflammation and stress in female dogs. The anti-inflammatory effects of melatonin have been reported in several studies. OBJECTIVES: The goal of this study was to assess the effects of melatonin on the concentrations of melatonin, cortisol, serotonin, α-1-acid glycoprotein (AGP), serum amyloid A (SAA), c-reactive protein (CRP), interleukin-10 (IL-10), interleukin-8 (IL-8), interleukin-1ß (IL-1ß) and tumour necrosis factor-α (TNF-α) before and after OHE. METHODS: The total number of animals was 25 and aligned in 5 groups. Fifteen dogs were divided into three groups (n = 5): melatonin, melatonin+anaesthesia and melatonin+OHE and received melatonin (0.3 mg/kg, p.o.) on days -1, 0, 1, 2 and 3. Ten dogs were assigned to the control and OHE groups (n = 5) without melatonin treatment. OHE and anaesthesia were performed on day 0. Blood samples were obtained via jugular vein on days -1, 1, 3 and 5. RESULTS: Melatonin and serotonin concentrations significantly increased in the melatonin, melatonin+OHE and melatonin+anaesthesia groups compared with the control group, while cortisol concentration decreased in the melatonin+OHE group compared with the OHE group. The concentrations of acute-phase proteins (APPs) and inflammatory cytokines significantly increased after OHE. The CRP, SAA and IL-10 concentrations decreased significantly in the melatonin+OHE group compared with the OHE group. The concentrations of cortisol, APPs and proinflammatory cytokines increased significantly in the melatonin+anaesthesia group compared with the melatonin group. CONCLUSIONS: The oral administration of melatonin before and after OHE help controlling the high levels of inflammatory APPs, cytokines and cortisol induced by OHE in female dogs.

Effects of short-term administration of melatonin before gonadectomy on oxidative stress, cortisol and sex hormones in male dogs.

The aim of this study was to investigate gonadectomy stress, steroid hormones and serotonin in male dogs treated with melatonin before gonadectomy. Twenty-five mixed breed adult dogs were divided into five equal groups. The melatonin and melatonin + gonadectomized groups received melatonin treatment (3 mg/10 Kg, PO, TID) the day before gonadectomy; the gonadectomized and anaesthesia groups did not receive melatonin; and the control group just received the melatonin vehicle. Blood sampling was performed before melatonin administration (day -1) and on days 0 (gonadectomy), 1, 3 and 6 after gonadectomy. Superoxide dismutase and glutathione peroxidase concentrations decreased significantly in gonadectomized dogs compared with dogs treated with melatonin before gonadectomy and intact dogs. Gonadectomy led to a significant decrease in catalase concentration in gonadectomized dogs compared with other study groups. Malondialdehyde levels increased significantly in gonadectomized dogs compared with other groups. Melatonin administration before gonadectomy led to decreased malondialdehyde concentration in gonadectomized and intact dogs compared to the control group. Cortisol concentration increased significantly in gonadectomized dogs compared to the control dogs. Serotonin levels decreased in gonadectomized dogs, but melatonin treatment increased serotonin concentration in gonadectomized and intact dogs. Melatonin treatment before gonadectomy suppressed oxidative stress and the cortisol but increased serotonin level.

The effects of melatonin treatment on oxidative stress induced by ovariohysterectomy in dogs.

BACKGROUND: As one of the most common surgeries performed in veterinary medicine, ovariohysterectomy (OHE) can induce oxidative stress in dogs. The antioxidant properties of melatonin have been confirmed in various studies. This study aimed to investigate the effects of melatonin administration on oxidative stress in dogs before and after OHE. In this study, 25 mature female intact dogs were selected and randomly divided into five equal groups: Melatonin (melatonin, no surgery), OHE (no melatonin, surgery), OHE + melatonin (melatonin, surgery), anesthesia+melatonin (melatonin, sham surgery), and control (no melatonin, no surgery) groups. Melatonin (0.3 mg/Kg/day, p.o.) was administrated to the dogs in the melatonin, OHE + melatonin, and anesthesia+melatonin groups on days - 1, 0, 1, 2, and 3 (day 0 = OHE). Blood sampling was performed on days - 1, 1, 3, and 5 of the study. Blood samples were immediately transferred to the laboratory and sera were separated and stored at - 20 °C. Superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and malondialdehyde (MDA) concentrations were measured with commercial kits. RESULTS: The levels of SOD, GPX and CAT were significantly higher in the melatonin and anesthesia+melatonin groups compared to those of the control group at days 3 and 5. The level of antioxidant enzymes significantly decreased in the OHE group compared to that of other groups at days 3 and 5. The administration of melatonin increased the level of antioxidant enzymes in ovariohysterectomized dogs. Ovariohysterectomy significantly increased the concentration of MDA in comparison to that of other groups at day 3. Melatonin administration significantly decreased the level of MDA in melatonin, anesthetized, and ovariohysterectomized dogs at day 3. CONCLUSIONS: Administration of melatonin on day - 1, 0, 1, 2 and 3 modulate the oxidative stress induced by OHE in dogs by increasing antioxidant enzymes concentration and decreasing MDA levels.

Use of ovine acellular peritoneal matrix combined with honey and ovine fetal skin extract in the healing of full-thickness infected burn wounds in a rat model.

Treatment of infected burn wounds remains a challenge in burn units. Silver-sulfadiazine (SSD) is the most commonly used topical antimicrobial agent in managing these wounds. We aimed to accelerate the healing of burn wounds by combined application of ovine acellular peritoneal matrix (OAPM), honey (H), and ovine fetal skin extract (OFSE). Sixty-four standardized burn wounds were created on the dorsum of 16 rats and were subsequently inoculated with Staphyloccocus aureus and Pseudomonas aeruginosa. After 48 hr, the wounds were surgically debrided and received either physiologic saline (control group) or SSD, OAPM+SSD, OAPM+H+SSD, and OAPM+H+OFSE+SSD. The healing wounds were evaluated for size, bacterial counts, histopathology, and biomechanical properties on days 3, 7, 14, 21, and 28 after surgery. All treatments had effectively reduced the level of S. aureus and P. aeruginosa on wounds compared to the control group by day 3 and 7. The wounds treated with combined application of OAPM+H+OFSE+SSD demonstrated considerable inflammation reduction, fibroplasia, complete re-epithelialization, and wound contraction together with significantly lesser scar tissue formation. Treatment with OAPM+H+OFSE+SSD showed superior biomechanical properties of the healing wounds. The findings suggested that the synergistic effect of dressing the wounds with OAPM, H, and OFSE was a very effective approach in accelerating the healing process of the experimentally induced infected full-thickness burn wounds in rats.

Epididymis ligation: a minimally invasive technique for preparation of teaser rams.

OBJECTIVE: To describe a minimally invasive technique for preparation of teaser rams by needle-assisted ligation through the tail of the epididymis. STUDY DESIGN: Experimental study. ANIMALS: Mature rams (n=6), estrus-induced ewes (2). METHODS; After local anesthesia, epididymis ligation was achieved by restraining the testis distally within the scrotal sac and passing suture through a hypodermic needle inserted between tail of epididymis and distal pole of testis, caudomedial to craniolateral through the scrotum. The needle was removed leaving the suture in place and the testis pushed up dorsally, then the needle was reinserted through the original holes and the suture passed back through the needle, which was withdrawn. This resulted in the suture forming a complete loop around the epididymis. The suture ends were tied ligating the epididymis. Semen was evaluated pre- and postligation. Testes were removed after 30 days for gross and histologic examination. RESULTS: Epididymis ligation was accomplished without postoperative complications. Three weeks after the epididymis ligation, no motile and live spermatozoa were found in ejaculates. From 5 to 28 days after epididymis ligation, attraction to ewes and libido was unchanged and similar to 14 days before ligation. CONCLUSIONS: This novel minimally invasive technique is a simple, alternative method for preparation of teaser rams. CLINICAL RELEVANCE: This method is simply performed, without skin wounds, and minimal postoperative care is needed. The technique should be readily adaptable to other species.