Fernanda Bastos de Mello

Sedation Effect of Acepromazine and Butorphanol in Dopplervelocimetric Parameters in Great Abdominal Arteries and Femoral Artery in Dogs

Background: Doppler ultrasound is a non-invasive diagnostic imaging technique that allows vascular anatomical and dynamics evaluation. Each artery has flow velocity profiles and different Doppler spectrum. The purpose of this study was to determine if sedation with acepromazine and butorphanol in dogs alters Doppler velocimetric values and diameter from abdominal aorta, celiac, mesenteric cranial, renal, external iliac and femoral arteries of healthy dogs. Materials, Methods & Results: Twenty healthy female dogs, aged 1 to 5 years, with body weight ranging from 10 to 25 kg, were evaluated with Doppler ultrasound in order to obtain: peak systolic velocity, end diastolic velocity, time average medium velocity, time average maximum velocity, resistive index, pulsatility index, and diameter from abdominal aorta, celiac, mesenteric cranial, renal, external iliac and femoral arteries. The same animals were sedated with acepromazine (0.02 mg/kg) and buthorphanol (0.4 mg/kg) and the same parameters were reevaluated. The heart rate was also measured. The study was approved by the Animal Ethics Committee of UFRGS, under the 25552 protocol, and the owners signed an informed consent form. Statistical analysis was performed with pared t test.The heart rate was statistically significant different, 98 ± 20.13 bpm before and 79 ± 17.74 after sedation. The exam was done before and after sedation in all selected vessels, except the celiac and cranial mesenteric artery, which were possible only in 35% and 45% respectively. All measured arteries exhibit difference in at least two of the analyzed parameters, except femoral artery, that only diameter was different. Discussion: Each vessel was selected because of its importance, and each of them has its own characteristic waveform. Changes in patterns of flow velocity of the celiac artery and mesenteric can help to determine the physiological condition of the gastrointestinal tract; in the case of renal arteries are associated with diseases involving parenchyma and; thrombosis in the aorta and the iliac and femoral arteries may be difficult to evaluate without the Doppler image. Examination of the AC and AMC before and after sedation not could be performed in all animals, maybe because the present work was carried out with only fasting requirement, without using dimethicone, and one of the difficulties encountered was the presence of gas in the gastrointestinal tract. Another factor that may have contributed to these findings is that the acute stress of containment and other environmental factors can cause release of vasopressin and leads to vasoconstriction of the splanchnic vascular bed. The dopplervelocimetric data found in celiac, mesenteric cranial, renal and femoral arteries in non-sedated animals was similar to what was described by other authors. Although all dogs demonstrated relaxation during the exam, this sedation protocol alters the values found with Doppler ultrasound in the selected vessels, except femoral artery, which caused only increase of diameter. The Doppler differences found can be a consequence of a decrease in heart rate associated with longer cycle length, and therefore, larger diastolic volume with vessels that stayed with same diameter, or in case of caudal abdominal aorta, that reduced the diameter. This study compared the dopplervelocimetric values to the ones described by other authors in non-sedated animals and demonstrated that although acepromazine and buthorphanol are a good option to sedate dogs to perform ultrasound exam, they alter the Doppler values from aorta abdominal, celiac, cranial mesenteric, renal, external iliac arteries and the femoral artery diameter.

Effects of environmental enrichment on reproductive performance and quantity and morphology of cumulus-oocyte complexes obtained from Rattus norvegicus

Several researchers have observed that environmental enrichment (EE) can be effective in reducing stressful conditions and abnormal behavior and may provide better reproductive performance in rodents. In this context, this study aimed to evaluate the reproductive performance of Wistar rats reared in three different housing conditions. Animals were separated into breeding pairs, one pair per cage and pairs randomly assigned to three experimental groups (ten couples per group): control group were provided cages without any environmental enrichment; PVC group with PVC pipe; and cardboard roll group with a commercially available cardboard tube. To compare the reproductive performance of the three groups, the following were evaluated: number of pups/litter; number of litters; parturition interval; occurrence of cannibalism; weight gain of offspring; as well as the quantity and quality of cumulus-oocyte complexes (COCs) obtained after superovulation of the females born from the first, second and last pregnancy in all groups. Moreover, the plasma level of corticosterone in breeding animals was measured. A total of 60 male rats randomly selected from the first- and last-born litters (20 males from each group) were first tested in an elevated plus-maze (EPM) and on the following day, were tested in an open field test (OFT). Significant differences were found in the number and morphological classification of COCs. In the control group, the number of oocytes in grade 4 (unusual shapes and very heterogeneous ooplasm, presenting no layers of surrounding cumulus cells [13]) presented statistically higher rates (225/2535, 8.9%) compared to the other groups, as well as the number of competent oocytes was higher in the enriched groups (pxa0=xa00.001). Moreover, we find that the males of cardboard roll group differed significantly in weight gain compared to PVC group (pxa0=xa00.008). In addition to this, we did not detect occurrence of cannibalism in this group. Our findings suggest that environmental enrichment provides improvements in reproductive performance of Wistar rats.