Characteristics of intramuscular collagen in calf-fed Nellore bulls and steers throughout the finishing phase.

This study evaluated collagen solubility and gene expression of biomarkers for intramuscular collagen (IMCT) deposition and remodeling in the Longissimus muscle of bulls and steers through the finishing phase. Thirty-six Nellore calves were used (18 bulls and 18 steers), and six of each sexual condition were randomly assigned to be harvested at 0, 100, or 200 days on feed (DOF) to evaluate collagen characteristics in different time points throughout the finishing phase. Bulls showed a greater collagen solubility than steers (P = 0.03). The gene expression of fibrogenic markers (TGFß1, COL1A1, and COL3A1) and IMCT remodeling mediators (MMPII, TIMPII, and LOX) were not affected by sexual condition or DOF (P > 0.05). Our data indicate that young Nellore bulls have a higher percentage of soluble intramuscular collagen, possibly due to higher collagen remodeling associated with a faster growth rate and muscle hypertrophy. Moreover, castration and DOF did not modify mRNA levels of fibrogenic and collagen remodeling markers.

Immunohistochemical Expression of Collagens in the Skin of Horses Treated with Leukocyte-Poor Platelet-Rich Plasma.

This study evaluated the immunohistochemical expression of type I (COL I) and III (COL III) collagens during the healing process of skin treated with leukocyte-poor platelet-rich plasma (LP-PRP). Seven healthy gelding crossbred horses aged 16 to 17 years were used. Two rectangle-shaped wounds were created surgically in the right and left gluteal regions. Twelve hours after wound induction, 0.5 mL of the LP-PRP was administered in each edge of the wounds of one of the gluteal regions. The contralateral region was used as control (CG). Three samples were obtained: after wound induction (T0), 14 days (T1) of healing process, and after complete closure of the skin (T2). The normal skin (T0) showed strong staining for type III and I collagen in papillary and reticular dermis, respectively. In the scar of the treated group, COL III showed important (p < 0.05) increase in immunoreaction in T2 compared with T1. The administration of a single dose of LP-PRP 12 h after induction of wound in horses does not influence formation of collagens I and III. However, the intense labeling for COL III suggests that the tissue was still weak during the macroscopic closure of the wound, demonstrating that healing was not completely finished.

Ambulatory esophageal pHmetry in healthy dogs with and without the influence of general anesthesia.

This research aimed to determine the value of esophageal pH in awake and anesthetized dogs, to evaluate the esophageal pH value in awake dogs, in different body positions, as well as to study the occurrence of gastroesophageal reflux episodes in these positions. Thus, 40 healthy male and female adult dogs with mean body weight of 15.5 ± 4.6 kg were used. Esophageal pHmetry was conducted by inserting a catheter through the oropharynx in 30 dogs (stage 1) anesthetized with acepromazine, propofol and isoflurane, submitted to elective ovariosalpingohysterectomy. In addition, 8-h esophageal pHmetry was carried out transnasally in 10 awake dogs (stage 2), allowed to move and change body positions (lateral and sternal decubitus, and standing position), which were recorded. The mean esophageal pH value was lower (p < 0.01) in the anesthetized dogs (7.3 ± 0.82) than in the awake dogs (8.2 ± 0.3). Only four anesthetized dogs (13.33%) suffered reflux episodes. Reflux was not observed in the awake dogs and no esophageal pH differences were found between the body positions studied. Compared to the alert state, general anesthesia in dogs submitted to the previously mentioned anesthesia protocol causes esophageal pH reduction and predisposes to the occurrence of gastroesophageal reflux episodes. Transnasal pHmetry of 8 h in healthy awake dogs reveals that the esophageal pH value is alkaline and does not vary according to body position. In these animals, decubitus position is not a determining factor for reflux episodes to occur.