Clinical evaluation of the sedative, antinociceptive and cardiorespiratory effects of intranasal dexmedetomidine combined with methadone in healthy dogs.

In this prospective, randomised, blinded clinical study, we compared the sedative, antinociceptive and cardiorespiratory effects of intranasal (IN) dexmedetomidine at 5 µg/kg (diluted with 0.03 mL/kg NaCl 0.9%, DEX) with or without methadone (0.3 mg/kg; DEXMET), through a mucosal atomization device to one nostril in twenty healthy client-owned dogs. At 5-min intervals over 45 min, sedation score, onset, cardiopulmonary variables, mechanical nociceptive thresholds (MNTs) were assessed, also ease of administration, adverse effects, and response to IV catheterization. Statistical analysis employed t-test, the Mann-Whitney U, repeated measures ANOVA and Chi-square tests as appropriate (P < 0.05). Higher sedation ocurred in DEXMET (7 [5-10]) compared to DEX (5 [2-7]) from 15 to 30 min (P < 0.01, median [interquartile range]). Heart rate was lower in DEXMET (P < 0.01; 65% reduction vs. 41% in DEX, P = 0.001). The MNTs were higher in DEXMET than DEX from 15 to 45 min (P < 0.01), peaking at T30 (17.1 ± 3.8, DEXMET and 8.5 ± 5.4 N, DEX). No differences were observed in mean arterial blood pressure and respiratory rate. Intranasal administration was considered easy for 8 dogs per group. Reverse sneezing (8 dogs; P < 0.001), sialorrhea and retching (4 and 2 dogs, respectively) occurred in DEXMET. Response to catheterisation was lower in DEXMET than DEX (P = 0.039; 2 and 7 dogs, respectively). In conclusion, intranasal methadone (0.3 mg/kg) increased the sedative and antinociceptive effects produced by dexmedetomidine (5 µg/kg) in healthy dogs and resulted in lower heart rate.

Comparison of CPAP and oxygen therapy for treatment of postoperative hypoxaemia in dogs.

OBJECTIVE: To compare 5 cmH2 O of continuous positive airway pressure with oxygen therapy in dogs recovering from general anaesthesia with low SpO2 values. continuous positive airway pressure is more effective than oxygen therapy in restoring normoxaemia (SpO2 ≥95%). MATERIALS AND METHODS: Prospectively, dogs recovering from anaesthesia, with SpO2 <95% after extubation (T0), were randomised and treated with continuous positive airway pressure (FiO2 0.21) or oxygen (O2 ; FiO2 0.35-0.40) therapy. Dogs were monitored with SpO2 every 15 minutes for 1 hour (T15, T30, T45, T60). Data from normoxaemic dogs (SpO2 >95%) were used as control (CTR). RESULTS: Of the 42 dogs enrolled, 34 completed the study. Eleven dogs were treated with O2 , 10 with continuous positive airway pressure and 13 were CTR. The SpO2 values at T0 were similar in the continuous positive airway pressure and O2 groups and were lower than in the CTR group. At T15, T30, T45 and T60, the SpO2 values in the continuous positive airway pressure group were higher than at T0; these were similar to those of the CTR group at the same time-points. In the O2 group, SpO2 values were significantly higher at T45 and T60 than at T0; 45.5% of dogs became normoxaemic at T45 and the remaining dogs became normoxaemic at T60. The average time to reach normoxaemia in the O2 group (53.1±7.3 minutes) was longer than in the continuous positive airway pressure group (15.0±0.0 minutes). CLINICAL SIGNIFICANCE: In dogs recovering from general anaesthesia with pulmonary gas exchange impairment, normoxaemia is restored more effectively and rapidly by using continuous positive airway pressure than by oxygen therapy.

Remifentanil and cyclooxygenase inhibitors interactions in the minimum alveolar concentration of sevoflurane in the rat.

BACKGROUND: Intraoperative opioids reduce anaesthetic requirements and thus limit the side-effects derived from high doses of the latter. Cyclooxygenase (COX) inhibitors can also be given but it remains unclear whether they further reduce the anaesthetic requirements. Our aim was to determine whether COX inhibitors potentiate the effect of remifentanil on the minimum alveolar concentration (MAC) of sevoflurane anaesthetized rats. METHODS: Male Wistar rats received remifentanil under sevoflurane anaesthesia, and the MAC was determined before and at two time intervals after, separated by 1.5 h. Rats were randomly allocated to receive paracetamol, metamizole, ketoprofen, or parecoxib just before one of the two studied time intervals. The MAC was determined from alveolar gas samples at the time of tail clamp. Data were analysed with an analysis of variance for repeated measures. RESULTS: Paracetamol potentiated the MAC reduction produced by remifentanil in rats (P=0.002), whereas metamizole, ketoprofen, and parecoxib failed to produce such an effect. Furthermore, paracetamol and remifentanil produced a maximum degree of MAC reduction [35 (10)%] even when a tolerance effect to remifentanil was observed in animals given remifentanil alone (P<0.001). A tolerance to remifentanil was not observed when metamizole, ketoprofen, or parecoxib was given once the opioid infusion has been started (P>0.05). CONCLUSIONS: COX inhibitors differentially potentiate the analgesic effect produced by remifentanil on the sevoflurane MAC, and paracetamol was the most effective drug. However, since all COX inhibitors prevented a tolerance effect to opioids once it was established, intraoperative rather than preoperative administration of these drugs is suggested.

Guidelines for the veterinary care of laboratory animals: report of the FELASA/ECLAM/ESLAV Joint Working Group on Veterinary Care.

Veterinary professionals working in partnership with other competent persons are essential for a successful animal care and use programme. A veterinarian's primary responsibilities are defined by their own professional regulatory bodies, but in this area of work there are further opportunities for contribution, which will assist in safeguarding the health and welfare of animals used in research. These guidelines are aimed not only at veterinarians to explain their duties, and outline the opportunities to improve the health and welfare of animals under their care, but also at employers and regulators to help them meet their responsibilities. They describe the desirability for postgraduate education towards specialization in laboratory animal medicine and detail the many competencies necessary to fulfil the role of the laboratory animal veterinarian. They detail the need for veterinary expertise to promote good health and good welfare of animals used in biomedical research during husbandry as well as when under experimental procedures. Regulatory and ethical aspects are covered as are the involvement of the veterinarian in education and training of others working in the animal care and use programme. Managerial aspects, including occupational health and safety, are also areas where the veterinarian's input can assist in the successful implementation of the programme.

Clinical comparison of the effects of isoflurane or propofol anaesthesia on mean arterial blood pressure and ventilation in dogs undergoing orthopaedic surgery receiving epidural anaesthesia.

The aim of this study was to compare the effects on mean arterial pressure (MAP) and ventilation of propofol total IV anaesthesia (TIVA) and isoflurane as anaesthetic maintenance in healthy dogs undergoing orthopaedic surgery, with epidural anaesthesia. Dogs were premedicated IM with dexmedetomidine (4µg/kg) and methadone (0.3mg/kg), induced with IV propofol (0.65-5mg/kg) and randomly assigned to be maintained with isoflurane (group I) or propofol (group P). Isoflurane end-tidal concentration (EtISO) and propofol infusion rate were adjusted during the surgery to maintain a suitable anaesthetic depth. All dogs received bupivacaine (1mg/kg) and morphine (0.1mg/kg) in the lumbosacral epidural space (total volume 0.2mL/kg). MAP was recorded every 5min during the procedure. Statistical analysis was performed using parametric (Student's t test) and nonparametric (Mann-Whitney U-test, chi-square) tests, as appropriate. Anaesthetic maintenance in groups I and P was accomplished by providing a mean EtISO of 1.12±0.15% and a mean propofol infusion rate of 15.0±4.7mg/kg/h, respectively. MAP was significantly higher in group P than in group I (92±17mmHg versus 78±10mmHg; P=0.021). Eleven dogs in group P and two dogs in group I reached an EtCO2>7.3kPa, requiring mechanical ventilation (P=0.001). In combination with epidural anaesthesia, propofol TIVA improved MAP and is a suitable alternative to isoflurane in orthopaedic surgery of the hind limb in healthy dogs. Nevertheless, since it was associated with increased respiratory depression, mechanical ventilation should be available.

Successful use of lipid emulsion to resuscitate a foal after intravenous lidocaine induced cardiovascular collapse.

BACKGROUND: Lipid emulsion has been reported to be effective for the treatment of local anaesthetic overdoses in rats, dogs and man. OBJECTIVES: To describe the successful treatment of cardiovascular lidocaine toxicity in a foal with intravenous lipid administration. STUDY DESIGN: Observational study: case report. METHODS: An 8-month-old Arabian cross foal was anaesthetised for removal of the right alar fold and nasal plate. Anaesthesia was maintained with isoflurane in oxygen and lidocaine administered with a loading dose followed by a continuous rate infusion (CRI). The anaesthetic period was uneventful and 30 min before expected termination of the procedure lidocaine infusion was stopped. A sudden drop in mean arterial blood pressure was then observed. The ECG signal was lost, the end tidal CO2 tension dropped from 40 to 10 mmHg, corneal reflex was absent and asystole diagnosed. Cardiopulmonary resuscitation manoeuvres were immediately initiated, but epinephrine and atropine were unsuccessfully administered. Lipid emulsion was administered and the heart rate and arterial blood pressure gradually returned to normal. RESULTS: The foal recovered consciousness 3 h later, regained its sternal position, was responsive and 20 h later was able to stand up alone. MAIN LIMITATIONS: It will be necessary to evaluate a greater number of cases to determine the effectiveness of lipids in foals intoxicated with lidocaine. CONCLUSION: Intravenous lipid emulsion may be helpful in the treatment of potentially lethal cardiotoxicity attributable to lidocaine overdose in the foal.

Effects of dexmedetomidine administered at acupuncture point GV20 compared to intramuscular route in dogs.

OBJECTIVE: To compare the sedative effects produced by dexmedetomidine in dogs, administered either intramuscularly or into the Governing Vessel 20 acupuncture point. MATERIALS AND METHODS: Six dogs were sedated with 125 µg/m2 dexmedetomidine injected either intramuscularly in the gluteal muscles or subcutaneously into the acupuncture point and in random order. Sedation and analgesia were assessed blindly before and after treatments at regular intervals for 90 minutes or until the dogs fully recovered. Duration and quality of sedation were assessed with a numerical sedation rating scale and a dynamic and interactive visual analogue scale. Analgesia was also assessed with a numerical rating scale. Heart and respiratory rates and rectal temperatures were recorded. RESULTS: Sedative and analgesic scores were significantly increased when dexmedetomidine was administered at the Governing Vessel 20 acupuncture point compared with the routine intramuscular route. Duration of sedation was longer in the acupuncture site injection group compared to the intramuscular group (93 ±38 and 41 ±16 minutes). Bradycardia was significantly more pronounced in the acupuncture site group than the intramuscular group, whereas respiratory rates and rectal temperatures did not differ between administration routes. CLINICAL SIGNIFICANCE: Administration at the Governing Vessel 20 acupuncture point increased the duration and degree of sedation and analgesic effects of dexmedetomidine compared with the intramuscular route.

Evaluation of an oesophageal Doppler device for monitoring cardiac output in anaesthetised healthy normotensive dogs.

OBJECTIVES: To compare cardiac output measured by oesophageal Doppler and by thermodilution monitoring and to correlate the Doppler cardiac output-generated minute distance with thermodilution cardiac output in healthy anaesthetised beagle dogs. MATERIALS AND METHODS: Prospective experimental study. Six healthy adult beagle dogs were pre-medicated with intramuscular acepromazine (0 · 05 mg/kg) and methadone (0 · 3 mg/kg). Anaesthesia was induced with intravenous propofol (dose-effect) and maintained with isoflurane in oxygen. Simultaneously, a constant rate infusion of dopamine (3 µg/kg/minute) was administered to the dogs to prevent hypotension. The minute distance, Doppler and thermodilution cardiac outputs were assessed at three different end-tidal concentrations of isoflurane (1 · 0, 1 · 3 and 2 · 0%). RESULTS: Correlation between Doppler and thermodilution cardiac output (r(2) = 0 · 582) and between minute distance and thermodilution cardiac output (r(2) = 0 · 658) were moderately good, but the limits of agreement between Doppler and thermodilution cardiac outputs were above the recommended values (±39%, for a recommended value up to 30%). CLINICAL SIGNIFICANCE: Doppler and minute distance cannot be considered as an alternative method to thermodilution to monitor cardiac output in the healthy anaesthetised dog.

Growth hormone plus high protein diet promotes adaptation after massive bowel resection in aged rats.

OBJECTIVE: To determine whether GH improves adaptation following massive bowel resection in the aged rat fed on a high protein-content diet. MATERIAL AND METHODS: Seventy-seven male Wistar rats aged 22+/-1 months underwent 80% bowel resection or laparotomy (sham-operation). They were randomly placed into one of eight groups, treated with either growth hormone (1mg/kg/day) or saline, and fed a liquid diet containing either a high or a normal protein content. Intestinal tissue and blood samples were taken seven days after surgery and analysed to measure intestinal mucosal proliferation and mucosal height, as well as plasma levels of IGF-1 and somatostatin. RESULTS: Resection of the small bowel in aged rats remarkably increased villous height and crypt proliferation. Growth hormone did not potentiate the increase in mucosal height and crypt proliferation observed after intestinal resection in aged rats fed a normal protein content diet, but did in those receiving a high-protein diet. Plasma levels of IGF-1 and somatostatin were not modified by surgery or treatment. CONCLUSION: Growth hormone may increase the adaptation of intestinal mucosa in aged rats undergoing massive intestinal resection, but requires an adequate nutritional support with increased amounts of high quality protein.

Enriched protein diet-modified ghrelin expression and secretion in rats.

Gastrointestinal (GI) integrity and function are regulated by nutrition and growth factors. The discovery of ghrelin, a natural growth hormone (GH) secretagogue produced by the gastrointestinal (GI) tract, is a potential link between diet and growth signals. The aim of this study was to evaluate macronutrient effect on ghrelin expression and secretion in addition to some possible function in intestinal trophic status. Wistar rats were fed a high-carbohydrate, high-protein (HP), high-fat or standard (St) diet. Animals received the same daily food volume and caloric intake. After 7 days, animals were fasted for 24 h and blood and tissue samples were obtained just before feeding or at 2 or 6 h after feeding. Fasting high-protein-fed rats had higher ghrelin plasma levels than with rats fed the high-carbohydrate, high-fat or standard diets. Two-hours after refeeding, ghrelin plasma levels had decreased in all groups with a slight recovery at 6 h after refeeding, except in the high-protein group. Ghrelin plasma levels in rats fed with the high-protein diet correlated negatively with their GH and insulin-like growth factor 1 (IGF-1) plasma concentrations which were also the lowest among the study groups. In conclusion, ghrelin secretion was nutritionally manipulated because a protein-enriched diet increased its levels.

Antinociceptive and motor-blocking action of epidurally administered IQB-9302 and bupivacaine in the dog.

BACKGROUND AND OBJECTIVES: The aim of this study was to compare the antinociceptive and motor-blocking effects of epidurally administered IQB-9302 (C18H26N2O.HCl) and bupivacaine in the dog. METHODS: Twelve adult female Beagle dogs were used. Each animal received 3 concentrations (0.25%, 0.50%, and 0.75%) of either IQB-9302 (n = 6) or bupivacaine (n = 6) by means of a chronic epidural catheter. The nocifensive and motor-blocking status were determined at regular intervals before (baseline) and after drug administration. RESULTS: Epidurally administered IQB-9302 caused a more potent nocifensive and motor-blocking action than bupivacaine. The duration of complete nocifensive block was the longest with IQB-9302, whereas the duration of dermatome nocifensive block was similar for both drugs. The nocifensive to motor block ratio was significantly higher with IQB-9302. CONCLUSIONS: IQB-9302 produced an anesthetic action similar to that of bupivacaine, although the former drug induced a slightly more potent nocifensive block. Nocifensive and motor block duration are very similar with IQB-9302, whereas bupivacaine induces a more prolonged motor block without nocifensive block.

L-aspartate aminotransferase and L-asparaginase in rat lymph node: a histoenzymological and immunohistochemical study.

L-asparaginase and L-aspartate aminotransferase are both involved in the synthesis of L-aspartic acid. It has been observed that L-asparaginase is involved in the immunosuppressor morphine-dependent syndrome in lymphoid cells whereas L-aspartic acid blocks the development of this syndrome. The aim of the present study was to clarify the localization of L-AATase activity and L-asparaginase in rat lymph nodes using histoenzymological and immunohistochemical methods, respectively. No positive reaction was demonstrated for L-AATase while L-asparaginase shown to be present in lymphocytes and lymphoblastic cells. These observations lead us to suggest that L-asparaginase is the enzyme mainly responsible for the synthesis of the L-aspartic acid necessary for satisfying the living requirements of lymphoid cells. Therapeutically administered L-asparaginase could exert its action intracellularly after crossing the cell membrane.

Actions of xylazine in young swine.

OBJECTIVE: To determine sedative, analgesic, and basic cardiovascular effects of xylazine administered to pigs. ANIMALS: 6 two-month-old Landrace x Large White pigs. PROCEDURE: Xylazine was administered i.v. at increasing dosages (1, 2, 4, 8, and 16 mg/kg of body weight) to otherwise unmedicated, conscious pigs, and the aforementioned effects were determined before xylazine administration and 2, 5, 10, and 15 minutes later. Then a higher xylazine dosage was given after the 15-minute measurements were taken. RESULTS: None of the xylazine dosages induced sufficient analgesia to prevent painful response to tail clamping; considerable excitation with vocalization and without appreciable sedative effect was observed at all dosages. At lower dosages, cardiovascular effects were characterized by bradycardia and biphasic blood pressure response; initial hypertension was followed by hypotension. At higher dosages, severe hypotension with moderate bradycardia was followed by marked bradycardia and return to normal baseline values or slight increase in blood pressure. CONCLUSION: Xylazine did not induce adequate sedative or analgesic effects in pigs at any dosage tested; however, cardiovascular effects were considerable. These effects of xylazine differ from those observed in other domestic species.

Reduction of isoflurane MAC with buprenorphine and morphine in rats.

Preoperative analgesics are being increasingly used to provide analgesia in the intraoperative and postoperative period. Opioids reduce anaesthetic requirements, although the effect varies with the different drug and species. The aim of this work was to determine whether buprenorphine reduces the minimum alveolar concentration (MAC) of isoflurane in a dose-related fashion, and whether this effect is similar to morphine when clinical doses of both drugs are used in the rat. Thirty-six male Wistar rats were anaesthetized with isoflurane, and MAC was determined before and after the administration of either buprenorphine or morphine. MAC of isoflurane was determined from alveolar gas samples when a standard noxious stimulus, in the form of a tail clamp, was applied. The duration and degree of reduction of the MAC of isoflurane were recorded. Basic cardiovascular and respiratory measurements were also recorded. Buprenorphine (10, 30 and 100 microg/kg) and morphine (1, 3 and 10 mg/kg) reduced in a dose-dependent fashion the MAC of isoflurane by 15%, 30% and 50%, respectively. Buprenorphine resulted in less cardiovascular and respiratory depression and had a longer-lasting action than morphine. In conclusion, buprenorphine has a dose-related isoflurane sparing effect in the rat similar to that caused by morphine at clinical doses of both drugs.

[Response of the intestinal mucosa to different enteral diets in situations of surgical stress and malnutrition]. / Respuesta de la mucosa intestinal a diferentes dietas enterales en situaciones de estrés quirúrgico y desnutrición.

INTRODUCTION AND OBJECTIVES: malnutrition and surgical stress is a relatively common association. At present, different enteral nutrition formulation are available, which are potentially applicable to different pathological conditions. The use of one diet or another may modify both the nutritional state as the intestinal structure and function. The objective of this study is to evaluate, in a malnutrition and surgical stress model in the rat, the effect of four enteral diets on the ponderal and structural evolution of the intestinal mucosa. MATERIAL AND METHODS: adult Wistar rats weighing 230 g divided into four groups (n = 8/group), according to the enteral nutrition diet administered (elemental-elemental-028, polymeric with fiber-Enrich, peptidic with glutamine-Alltraq, and rich in arginine, fatty acids, and CO3 impact). All animals were subjected to an acute protein deficit for one week, and surgical stress consisting of the performance of a laparotomy. During another week the animals were fed with one of the four diets on a hypocaloric base of 195 kcal/week/rat, to maximize the effects of each diet, after which the animals were sacrificed. Determinations were made of body and intestinal weight variations, and samples were taken of the jejunum, ileum, and colon tissue. A histomorphometric study was conducted on these samples (crypt length and villosity). RESULTS: all groups lost weight in a similar manner with respect to the initial weight, with the exception of the animals fed with the polymeric diet with fiber, whose weight loss was even more marked. The intestinal weight was greater in those animals who received an arginine rich diet. In the jejunum and ileum samples the villus length was greatest in the group receiving a glutamine rich diet, with the length being shortest when fed with the elemental diet. The crypt depth showed as similar variation. In the colon, the greatest crypt depth was seen in the animals who received a fiber rich diet. DISCUSSION AND CONCLUSIONS: diets rich in glutamine and arginine, as well as the elemental diet, are more efficient when it comes to maintaining body weight, although the latter is the one which maintains the small intestine weight the least, without there being a direct relation between these two parameters. The enriched diets are the ones which give the best results when it comes to maintaining body weight and mucosal mass. In the colon, the fiber enriched diet stimulate the growth of colonic mucosa.

[Importance of the colon in intestinal adaptation. Study with the proliferating cell nuclear antigen]. / Importancia del colon en la adaptación intestinal. Estudio mediante el antígeno nuclear de proliferación celular.

Proliferating cell nuclear antigen (PCNA) is an auxiliary protein to DNA polymerase delta necessary for tissue cellular proliferation. The colon releases several peptides or hormones which are probably related to intestinal proliferation. Colonic resection determines adaptive changes in the remnant bowel. In the present study, proliferative changes after colectomy were studied by means of the murine monoclonal PC10 antibody. A control group (n = 10 rats) and a 75% proximal colon resection group (n = 10 rats) were studied. 14 days after resection, jejunal, ileal and colon samples were taken and assayed for PCNA. Relationship between immunostained nuclei and the total number of nuclei was determined. The three intestinal segments showed statistically significant increases (p < 0.001) in the number of immunostained nuclei. PCNA proliferative index was greater in the remnant large bowel.

[Administration of growth hormone enhances the intestinal adaptive response after resection of small intestine in rats]. / La administración de hormona de crecimiento incrementa la respuesta adaptativa intestinal posterior a una resección de intestino delgado en la rata.

The aim of this study was to assess the proliferative effect of growth hormone (GH) on the remnant intestinal mucosa after small bowel resection in the rat. Three groups (n = 8/group) of adult Wistar rats were established as follows: 1) control, 2) 90% small bowel resection (SBR) and 3) 90% small bowel resection + GH 1 mg/kg-day (SBR+GH) during 7 days. Ileal samples were taken prior to resection (basal), and at sacrifice, for assessment of intestinal mucosal growth by means of morphometric (crypt and villous length) and proliferative (proliferating cell nuclear antigen, PCNA) techniques. GH administered to resected rats (SBR+GH) significantly increased the number of proliferating cells and crypt and villous length when compared to resected non-treated animals (SBR). In conclusion, in the rat, GH markedly increases the trophic action of intestinal mucosa in hyperproliferative states like massive bowel resection, enhancing remnant bowel morphologic and proliferative adaptation.

Comparative effect of growth hormone and plerocercoid growth factor in the intestinal resection in rat.

OBJECTIVE: After massive bowel resection, absorption depends on how fast the mucosal adaptation takes place. This work aims at assessing the trophic effect of growth hormone (GH) and its analogue, the plerocercoid growth factor (PGF), on the intestinal mucosa after 90% small bowel resection. EXPERIMENTAL DESIGN: 24 male Wistar rats were divided into four groups of 6: Control (laparotomy), 90% small bowel resection (RID), resection and treatment with GH during 14 days (RID + GH) and resection and PGF treatment (RID + PGF). Intestinal mucosal adaptation was assessed by measuring mucosal weight and height, and evaluating the regenerative activity by measuring proliferation cell nuclear antigen (PCNA) labelling index. RESULTS: Bowel resection itself caused a significant increment of jejunal and ileal mucosal height in comparison with the control group. GH and PGF did not change this increase. Jejunal and ileal proliferation indexes were significantly higher than those in controls and they were significantly higher in both RID + GH and RID + PGF groups. CONCLUSIONS: GH and PGF cause a proliferative effect on the intestinal mucosa, even in hyperproliferative states such as the small bowel resection. This finding might have a clinic application.

[Intestinal trophic effect of neurotensin after colectomy]. / Efecto trófico intestinal de la neurotensina tras colectomía.

Neurotensin is a trophic peptide for the intestinal mucosa. Intestinal resection is a well known adaptive process of mucosal growth. Our aim was to determine the effect of exogenous neurotensin administration on intestinal mucosal growth after colectomy in the rat. Two groups: colon resection (n = 15) and colon resection plus neurotensin (n = 15, 600 micrograms/kg/day, 13 days post-surgery) were studied. Intestinal growth was assessed by means of the proliferating cell nuclear antigen (PCNA) technique on the intestinal crypt. Our results showed that neurotensin increased (p < 0.0001) epithelial cell growth when compared to non treated animals. Body weight loss was found in the non treated group but not in neurotensin treated animals. In conclusion, neurotensin increases cell growth in rats with colectomy, and maintains body weight. Neurotensin may have beneficial effects in colectomized patients.

[Somatostatin and growth hormone in post-colectomy intestinal hyperplasia in rats]. / Somatostatina y hormona de crecimiento en la hiperplasia intestinal post-colectomía en la rata.

AIM: Somatostatin exerts significant effects on gastrointestinal function that may include mucosal growth regulation, probably through its action on growth hormone release. The aim of this work was to correlate somatostatin and growth hormone plasma levels and the hyperproliferative status of intestinal mucosa after colectomy. EXPERIMENTAL DESIGN: Adult Wistar rats were divided into two groups: control sham operated (n = 8) and large bowel resection (n = 8). Seven days post-colectomy, the animals were killed. Ileal mucosal samples were assayed for proliferative status (morphometry, and proliferating cell nuclear antigen labeling) and blood samples for plasmatic somatostatin and growth hormone measurement. RESULTS: A hyperproliferative status was observed with significant increases in villous length and crypt proliferating cell nuclear antigen labeling. Plasma somatostatin showed a 95% significant decrease while growth hormone levels increased significantly. CONCLUSION: The intestinal adaptation seen after colectomy is associated with lower somatostatin and higher growth hormone plasma level, possibly by regulating the intestinal adaptative process.