Wound Licking Research Articles

A Pharmacokinetic and Analgesic Efficacy Study of Carprofen in Female CD1 Mice.

The minimization of pain in research animals is a scientific and ethical necessity. Carprofen is commonly used for pain management in mice; however, some data suggest that the standard dosage of 5 mg/kg may not provide adequate analgesia after surgery. We hypothesized that a higher dose of carprofen in mice would reduce pain-associated behaviors and improve analgesia without toxic effects. A pharmacokinetic study was performed in mice given carprofen subcutaneously at 10 or 20 mg/kg. Plasma concentrations were measured at 0.25, 0.5, 1, 2, 4, 8, 12, 24, and 48 h after dosing (n = 3 per time point and treatment). At these doses, plasma levels were above the purported therapeutic level for at least 12 and 24 h, respectively, with respective half-lives of 14.9 and 10.2 h. For the efficacy study, 10 mice per group received anesthesia with or without an ovariectomy. Mice were then given 5 or 10 mg/kg of carprofen, or saline subcutaneously every 12 h. Orbital tightening, arched posture, wound licking, rearing, grooming, nesting behavior, and activity were assessed before surgery and at 4, 8, 12, 24, and 48 h after surgery. The von Frey responses were assessed before and at 4, 12, 24, and 48 h after surgery. The efficacy study showed that all surgery groups had significantly higher scores for orbital tightening, arched posture, and wound licking than did the anesthesia-only groups at 4, 8, 12, and 24-h time points. At the 8 h time point, the surgery groups treated with carprofen had significantly lower arched posture scores than did the surgery group treated with saline only. No significant differences were found between carprofen treatment groups for rearing, grooming, von Frey, activity, or nesting behavior at any time point. These results indicate that subcutaneous carprofen administered at these doses does not provide sufficient analgesia to alleviate postoperative pain in female CD1 mice.

Licking their wounds: Social response to trauma by free‐ranging bison (Bison bison)

AbstractThe epidermis of wild mammals is occasionally lacerated or punctured and wound care behaviours evolved to keep animals healthy in nature. Communal wound licking may promote healing of affected sites, relieve stress after a traumatic experience, and reinforce social bonds among individuals. Yet, there are few reported cases of communal wound licking in free‐ranging mammals. We report observations of communal wound licking in a social ungulate—free‐ranging bison (Bison bison). Two adult female bison presented with minor open puncture wounds after we chemically immobilized each of them with a dart fired from a rifle. The day after being darted, we observed three different adult bison lick the wounds of the two wounded bison. Both bison were <3 m of each other during this time and all of the observed wound licking occurred in <10 min. Our observation provides an additional example of communal wound licking in free‐ranging mammals and extends it to a social ungulate. Benefits to bison of communal wound licking are perhaps largely social. However, targeted research is needed to better understand both the frequency and cost and benefits of communal wound licking.

Pharmacokinetics and Efficacy of a Long-lasting, Highly Concentrated Buprenorphine Solution in Mice.

Buprenorphine is a commonly used opioid for mitigating pain in laboratory mice after surgical procedures; however, the dosing interval necessary for standard buprenorphine may require treatment every 4 to 6 h to maintain an adequate plane of analgesia. An alternative formulation that provides prolonged plasma concentration with long-lasting effects would be beneficial in achieving steady-state analgesia. We evaluated a long-lasting and highly concentrated formulation of buprenorphine (Bup-LHC) in mice. Pharmacokinetic analysis was performed to assess plasma concentrations in male C57BL/6J (B6) and female CD1 mice after subcutaneous injection of 0.9 mg/kg. The Bup-LHC formulation provided plasma drug levels that exceeded the therapeutic level for at least 12 h in male B6 mice and was below therapeutic levels by 8 h in female CD1 mice. An experimental laparotomy model was used to assess analgesic efficacy. Female CD1 mice were treated with either Bup-LHC (0.9 mg/kg) or saline at 1 h before undergoing an ovariectomy via a ventral laparotomy. At 3, 6, 12, 24, and 48 h after surgery, pain was assessed based on the following behaviors: orbital tightness, grooming, wound licking, rearing, arched posture, ataxia, piloerection, nest building, and general activity. At 3 and 6 h after surgery, Bup-LHC-treated mice had significantly less wound licking and orbital tightness and considerably higher activity levels than did saline-treated mice. At 12 h, wound licking, orbital tightness and activity in Bup-LHC-treated mice were no longer significantly different from those of saline-treated mice. The results of this study suggest that Bup-LHC at 0.9 mg/kg provides sufficient plasma concentrations for analgesia in mice for 6 to 12 h after administration, as demonstrated behaviorally for at least 6 h after surgery.

Why do male mice spit soluble enzymes that hydrolyze extracellular nucleotides? Focus on “Prostatic acid phosphatase is the main acid phosphatase with 5′-ectonucleotidase activity in the male mouse saliva and regulates salivation”

the 5′-ectonucleotidases found on the surface of most mammalian cells and in blood serum serve as a source of adenosine derived from extracellular nucleotide degradation (11). The 5′-ectonucleotidases are phosphatases whose substrate is extracellular adenosine 5′-monophosphate (AMP) generated from adenosine 5′-tri- and diphosphates (ATP and ADP) released from injured tissues to stimulate cellular responses via P2 purinergic receptors (7). A recent study by Quintero et al. (10) investigated prostatic acid phosphatase (PAP), a 5′-ectonucleotidase that plays a role in the development of adenocarcinoma of the prostate gland. These authors showed that PAP exists as two alternative splice variants, a transmembrane prostatic acid phosphatase (TMPAP) and secreted PAP (sPAP). TMPAP and sPAP are distinguished functionally from other 5′-nucleotidases through inhibition by l−(+)−tartrate, ability to cleave phosphomonoesters besides AMP, and activity over a wide pH range (i.e., 3–8). TMPAP activation inhibits endocytosis/exocytosis through interaction with snapin (10), a soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE)-associated protein (5) that negatively regulates secretory vesicle docking and fusion with plasma membranes (Fig. 1). In addition, adenosine generated by PAP is an agonist for G protein-coupled A1 adenosine receptors (A1R) that counteract the nociceptive (i.e., pain-producing) effects of ATP (4) occurring through activation of P2X receptor ATP-gated ion channels (2; Fig. 1). However, little information is available concerning physiological roles of sPAP in biological fluids. Fig. 1. Prostatic acid phosphatase (PAP) signaling in salivary glands and saliva. In this issue of American Journal of Physiology-Cell Physiology, Araujo et al. (1) attempt to understand the role of TMPAP and sPAP in a secretory organ, the submandibular gland (SMG), which secretes fluid, proteins, and other factors into saliva, thereby bathing the oral cavity with antimicrobial and digestive agents. Using PAP−/− mice, the authors evaluate effects of deletion of this 5′-ectonucleotidase on SMG function. Comparisons between PAP−/− and wild-type SMG indicate that TMPAP is primarily expressed in granular convoluted tubule (GCT) cells of the duct but not acinar cells. Remarkably, deletion of PAP increases α-adrenergic and muscarinic cholinergic receptor-mediated saliva secretion and enhances expression of genes promoting inflammation and proliferation, particularly interferon-dependent proinflammatory genes. The authors suggest that this increase in saliva secretion relates to loss of negative control by TMPAP of exocytosis (Fig. 1). PAP deletion also increases B and T cell infiltration of SMG and levels of miR-146a that have been associated with prevention of tissue damage. Together with observations of proliferating acinar cells after PAP deletion, these results strongly suggest that SMG homeostasis in PAP−/− mice is maintained by an immune response without salivary gland degeneration seen with immune cell infiltration of SMG in the autoimmune disease Sjogren's syndrome (SS; 3, 8). Another important finding is that sPAP is only present in male mouse saliva, which correlates with reduced levels of GCT cells in female versus male SMG and is consistent with sexual dimorphism in rodent salivary glands (6). The authors suggest that mouse sPAP plays a male-specific function in which licking of wounds (perhaps caused by fighting) deposits sPAP-containing saliva that induces an anti-nociceptive response in wounded tissue by participating in the generation of adenosine from released nucleotides to activate A1 receptors (Fig. 1). Since SS has a female predominance in rodents and humans (3, 8), it would be interesting to determine whether PAP in males plays a protective role in SS by promoting gland homeostasis and delay in the onset of salivary gland dysfunction and degenerative immune cell infiltration. Another question remaining is whether extracellular nucleotides are released into the oral cavity due to tissue injury of oral epithelium caused by inflammation, exposure to toxins, SS, and radiation-induced damage occurring as a side effect of cancer therapy. Once released, degradation of extracellular nucleotides by ectonucleotide diphosphohydrolases (eNTPDases), ectoATPases, and ectoADPases would generate AMP whereupon 5′-ectonucleotidases including PAP would yield adenosine that could either be taken up by nucleoside transporters in cells and salvaged or activate P1 adenosine receptors (7, 9, 11). Further study is needed to investigate whether sPAP in saliva plays a role in the regulation of purinergic signaling in the oral cavity under physiological and pathological conditions.

Effects of Rat's Licking Behavior on Cutaneous Wound Healing

Objective(s) Wound licking has been shown to advance wound healing among humans and many other animals. The present study evaluates the licking effects on healing of skin wound in rats. Materials and Methods Twenty four rats were assigned to 4 different groups randomly and two 3 cm longitudinal full thickness incisions were made on each dorsal and ventral side of rats. The ventral incisions were considered as treated wounds because of contact to saliva as rats lick them easily and dorsal incisions as control wounds. Clinical changes and histopathological effects of rat saliva on wound healing were evaluated every day and on 3, 7, 14 and 21 days post-operation respectively. Results Histologic and clinical evaluation of treated wounds showed better healing than control wounds. Conclusion This study showed that licking behavior can promote wound healing. Thus salivary compounds could be isolated, be mass produced and may have potential to become as common as antibiotic cream.

Histopathological effects of rat saliva on cutaneous wound healing

The effectiveness of wound licking with saliva on wound healing was evaluated in rats in this study. Saliva plays an important role in cutaneous wound healing and soft tissue. This may be because of existence of epidermal growth factor (EGF), nerve growth factor (NGF) and secretory leukocyte protein inhibitor (SLPI). Probably licking in animals such as rat because of EGF and others growth factors deposit onto the wound area enhances wound healing of skin. In this investigation, 24 seven-month years old female rats were randomly divided to four groups. Using aseptic surgical technique, in each rat, 2 incisions, 4 cm length, were made on the skin of the abdomen that animal could licked them as experimental groups and back of the neck as control incisions groups. Biopsies of the wounds were performed on days 3, 7, 14 and 21 postoperatically and were prepared for histopathological study. Abdominal incision showed infiltration of leukocytes, a few neutrophils, more macrophages, lymphocytes and beginning of re-epithelialization on postoperative day 3. There was no significant differences between experimental and control incisions on day 3 after operation except more dermal edema in abdominal incisions. Angiogenesis and proliferation of fibroblasts were more extensive on postoperative day 7 and 14 in abdominal wounds. On postoperative day 21, in abdominal incisions, predominant cells were fibrocytes that indicates hyperemia, severe angiogenesis and no hair follicles forming. These findings suggest that saliva could enhance cutaneous wound healing process.

Surgical implantation of radiotelemetry transmitters in European badgers (Meles meles).

The suitabilities of two subcutaneous and two intraabdominal surgical approaches were evaluated for implantation of telemetry transmitters in the European badger (Meles meles). Two transmitters, one for heart rate and the other for body temperature, were needed in each badger. Five wild badgers were trapped, housed in an outdoor pen, anesthetized, and surgically implanted with one or two transmitters per procedure. A total of 16 transmitters were implanted, 10 subcutaneously and six intraabdominally, and each badger had up to three procedures performed. Six subcutaneous transmitters were placed over the chest wall and four on the dorsal aspect of the neck. Three intraabdominal transmitters were placed free in the abdomen and three were fixed to the abdominal wall. Eight of the subcutaneous transmitters were later damaged or dislodged, probably by mechanical friction, injuries from fighting, or wound licking. The intraabdominal implantation procedures were easier and faster to perform compared with subcutaneous procedures. Two of the free intraabdominal transmitters became thinly encapsulated, with some omental adhesions. The fixed intraabdominal approach for transmitter implantation is preferable in badgers.

How far the stars?

How far the stars?

Extraction wound healing in desalivated rats

Wound licking has been shown to promote extraoral wound healing among animals. Although the oral mucosa is bathed in saliva. Little information about the role of saliva in oral wound healing is found. The present study evaluates the healing of extraction wounds in desalivated rats. Experimental rats underwent sialadenectomy of the submandibular and sublingual glands and ligation of the parotid ducts. Maxillary left first molars were extracted. Rats were killed at 0, 1, 3, 5, 7, 10, 14, and 21 days after surgery and maxillae were prepared for light microscopy examination. Generally, a delay in socket healing in the desalivated rats was found. No differences were observed in blood clot formation. Replacement of the clot by granulation tissue was relatively slow concomitant with a longer inflammatory process. Bone formation kinetics were slower among the experimental rats.

The effect of selective desalivation on wound healing in mice

The effectiveness of wound licking in the acceleration of wound healing was evaluated in selectively desalivated mice. Rate of healing of experimentally induced cutaneous wounds was evaluated macroscopically by photography at 0, 2, 4, and 6 days after wounding. Sialadenectomy of submandibular and sublingual glands significantly slowed down wound healing in animals caged together compared to sham-operated controls. Separate caging as compared to caging in groups slowed down healing in sham-operated animals at day 2 but not at day 4 and 6. No effect on the rate of healing in sialadenectomized mice was observed in separate caging compared to mice caged in groups. Ligation of the parotid duct had an insignificant effect. The rate of wound healing of sublingual sialadenectomized mice was slower than that of sham-operated controls, but not as slow as those of sublingual and submandibular sialadenectomized mice. The results suggest that the rate of healing of experimentally induced cutaneous wounds of mice is slowed down when licking is prevented by separate caging which confirms previous reports. Licking with submandibular saliva seems to be more effective than sublingual saliva. parotid saliva or minor salivary glands secretions are the least effective.

Effect of parotid submandibular and sublingual saliva on wound healing in rats

1. 1. The effectiveness of wound licking with parotid, submandibular or sublingual saliva on wound healing was evaluated in selectively sialadenectomized rats. 2. 2. The rate of healing of experimentally induced cutaneous wounds was evaluated macroscopically by photography at 0, 2, 4 and 6 days after surgery. 3. 3. Sialadenectomy of all major glands significantly slowed down wound healing compared to Sham-operated controls. 4. 4. Parotid licking had no effect compared to controls; submandibular licking and sublingual licking appeared to be very effective. 5. 5. The results suggest that saliva promotes wound healing in experimentally induced cutaneous wounds by communal licking; this is a result of the submandibular and sublingual saliva and not the parotid saliva.

Antibacterial properties of saliva: Role in maternal periparturient grooming and in licking wounds

Canine saliva was tested for its bactericidal effects against pathogens relevant to the presumed hygienic functions of maternal grooming of the mammary and anogenital areas and licking of wounds. Both female and male saliva were bactericidal against Escherichia coli and Streptococcus canis but only slightly, and nonsignificantly, bactericidal against coagulase positive staphylococcus and Pseudomonas aeruginosa. E. coli is the cause of highly fatal coliform enteritis of neonatal mammals and E. coli and S. canis are the main pathogens implicated in neonatal septicemia of dogs. The bactericidal effects of saliva would facilitate the hygienic function of maternal licking of the mammary and anogenital areas in protecting newborns from these diseases. E. coli and S. canis along with coagulase positive staphylococcus and P. aeruginosa are among the common wound contaminants of dogs. Wound licking, and the application of saliva, would thus reduce wound contamination by E. coli and S. canis. The resistance of staphylococcus to bactericidal effects of saliva may be a factor in the high frequency (46 percent) with which coagulase positive staphylococcus was isolated from wounds compared with much lower frequency (9–17 percent) with which E. coli and S. canis were isolated.

Biological effects of epidermal growth factor, with emphasis on the gastrointestinal tract and liver: an update.

Epidermal growth factor (EGF) is a 6,000 Da polypeptide hormone produced by glands of the gastrointestinal tract, namely the salivary and Brunner's glands. It is found in a wide variety of external secretions as well as in blood and amniotic fluid. In fetal and neonatal life, EGF appears to play an important role in the development of the oral cavity, lungs, gastrointestinal tract and eyelids. Its presence in cells of the central nervous system suggests that it also plays a role in modulating the development of this system. In adult animals, the function of EGF is much less well understood. In rodents, it apparently modulates acid secretion from parietal cells in the stomach, and it undoubtedly plays an important role in wound healing, either through its localization within skin or by the licking of wounds with EGF-containing saliva. Considerable evidence now suggests that it may be one of the key factors in initiating liver regeneration after partial hepatectomy or chemical injury. The liver appears to be the principal organ which regulates the circulating level of EGF. In fact, EGF is cleared so efficiently by the liver that only the peripheral cells of the lobule (zone 1) sequester EGF, and little remains in the circulation for cells in the more distal zones (zones 2 and 3). In the liver, EGF normally binds to a plasma membrane receptor and is internalized within the liver cell, where the vast majority of EGF and its receptor are destroyed in lysosomes. A small but consistent quantity of EGF enters the bile intact. In the regenerating liver, however, the lysosomal pathway appears to be shut down, and the EGF is diverted to hepatocyte nuclei prior to the initiation of DNA synthesis. Nuclear EGF is found free as well as bound to a high-molecular-weight protein which has many characteristics identical to the plasma membrane EGF receptor. The plasma membrane receptor is a large transmembrane glycoprotein of 170,000 Da containing four domains: an extracellular EGF-binding portion, a hydrophobic membrane-spanning segment, a proximal cytoplasmic domain which binds ATP and protein substrates containing tyrosine for phosphorylation and a terminal cytoplasmic portion with 3 tyrosines which undergo autophosphorylation after EGF binding.(ABSTRACT TRUNCATED AT 400 WORDS)

Nerve growth factor: acceleration of the rate of wound healing in mice.

Earlier studies have shown that removal of the submandibular glands of mice retards the rate of contraction of experimentally induced wounds and that communal licking of wounds accelerates contraction in intact animals [Hutson, J. M., Niall, M., Evans, D. & Fowler, R. (1979) Nature (London) 279, 793-795]. In the light of the observation that nerve growth factor (NGF) is secreted in high concentrations in mouse saliva, we have studied the effect of topically applied high molecular weight nerve growth factor (HMW-NGF) upon the rate of wound contraction in sialoadenectomized animals. Results show that HMW-NGF significantly accelerates the rate of wound contraction and that this phenomenon is probably dependent upon the enzymic activity of the protein. Neither diisopropyl fluorophosphate-inactivated NGF nor 2.5S NGF [isolated according to Bocchini, V. & Angeletti, P. U. (1969) Proc. Natl. Acad. Sci. USA 64, 787-794] displays this biological activity. Thus, it may be that one of the physiological roles of NGF in saliva is to promote wound healing by the licking process.