Meat quality, proximate composition and muscle fatty acid profile of young llamas (Lama glama) supplemented with hay or concentrate during the dry season.

Thirty llamas were used to study the effect of a 90 day feed supplementation on meat quality, chemical composition and muscle fatty acid profile. Treatments were: GR=llama on native pasture until slaughter; GR+SH=like GR, but with overnight free access to barley/alfalfa hay; and GR+SC=like GR, but with overnight free access to a wheat bran/sorghum grain concentrate. The supplementation had no effect on postmortem pH and temperature decline in the Longissimus lumborum muscle (LLM), cooking losses nor Warner-Bratzler shear force values (P>0.05). Meat from GR+SC llama had higher fat content in LLM (P<0.05) compared to GR and GR+SH llama. Intramuscular fat from GR+SH llama showed higher (P<0.01) proportions of polyunsaturated fatty acids, higher (P<0.05) polyunsaturated fatty acids/saturated fatty acids and desirable fatty acids ratio, lower (P<0.05) omega-6/omega-3 (n-6/n-3) ratio, and higher (P<0.01) conjugated linoleic acid.

Meat quality attributes of the Longissimus lumborum muscle of the Kh'ara genotype of llama (Lama glama) reared extensively in northern Chile.

Twenty male llama of the Kh'ara genotype, reared extensively in the north of Chile, were slaughtered at ages between 2 and 4 permanent teeth (2 to 3.5years) and analyses were carried out on the Longissimus lumborum muscle, including composition (moisture, fat, protein, ash, cholesterol, amino acids, fatty acid profile and collagen content) and meat quality parameters (pH, color, water holding capacity and Warner-Bratzler shear-force). Llama meat was characterized by a low cholesterol (39.04mg/100g) and intramuscular fat (1.56%) content, a total collagen content of 6.28mg/g, of which 20.28% was soluble collagen. Amino acid composition and fatty acid profile were similar to those found for beef finished on forage. Llama meat showed a low n-6/n-3 (4.69) and hypocholesterolemic/hypercholesterolemic (1.55) ratio and acceptable values of DFA (65.78%). Quality parameters in llama Longissimus muscle were within the ranges reported for more traditional meats such as beef and lamb.

Identification of cattle, llama and horse meat by near infrared reflectance or transflectance spectroscopy.

Visible and near infrared reflectance spectroscopy (VIS-NIRS) was used to discriminate meat and meat juices from three livestock species. In a first trial, samples of Longissimus lumborum muscle, corresponding to beef (31) llamas (21) and horses (27), were homogenised and their spectra collected in reflectance (NIRSystems 6500 scanning monochromator, in the range of 400-2500 nm). In the second trial, samples of meat juice (same muscle) from the same species (20 beef, 19 llama and 19 horse) were scanned in folded transmission (transflectance). Discriminating models (PLS regression) were developed against "dummy" variables, testing different mathematical treatments of the spectra. Best models indentified the species of almost all samples by their meat (reflectance) or meat juice (transflectance) spectra. A few (three of beef and one of llama, for meat samples; one of beef and one of horse, for juice samples) were classified as uncertain. It is concluded that NIRS is an effective tool to recognise meat and meat juice from beef, llama and horses.

Diagnóstico clínico-microbiológico de otitis externa en caninos de Bogotá – Colombia / Clinical – microbiological diagnostic of external otitis in canines in Bogotá - Colombia

Objetivo. Evaluar clínica y microbiológicamente la implicación de Malassezia sp como agente etiológico de otitis externas en caninos. Materiales y métodos. Se obtuvieron 166 muestras de hisopados óticos de caninos con sintomatología y hallazgos clínicos compatibles con otitis externa durante el periodo comprendido entre julio – diciembre 2008. A partir de las muestras se realizaron cultivos bacteriológicos y micológicos e identificación de género mediante perfiles bioquímicos para cada unos de los microorganismos aislados. Los datos clínicos asociados a la patología fueron consignados en una base de datos y posteriormente analizados en el programa estadístico SPSS 17 Resultados. A partir de la 166 muestras obtenidas, 59% (98) de ellas fueron positivas para el cultivo bacteriológico con predominio de Staphylococcus sp 37% (61) y 73% (121) positivas para Malassezia. De las 121 levaduras aisladas 32.2% fue Malassezia pachydermatis. El análisis estadístico no evidenció diferencias significativas con respecto a las relaciones entre variables (género, edad, raza, tipo de oreja y respuesta inflamatoria por citología) y el aislamiento de Malassezia sp. El nivel de significancia establecido para la prueba fue de 0.05%. Conclusiones. No se observaron asociaciones estadísticas entre las variables género, edad, raza frente a la otitis externa por Malassezia sp. Malassezia sp fue aislada en un 73% de los casos con otitis externa, con participación de diferentes agentes bacterianos especialmente Staphylococcus sp.

Alpha-amylase starch binding domains: cooperative effects of binding to starch granules of multiple tandemly arranged domains.

The Lactobacillus amylovorus alpha-amylase starch binding domain (SBD) is a functional domain responsible for binding to insoluble starch. Structurally, this domain is dissimilar from other reported SBDs because it is composed of five identical tandem modules of 91 amino acids each. To understand adsorption phenomena specific to this SBD, the importance of their modular arrangement in relationship to binding ability was investigated. Peptides corresponding to one, two, three, four, or five modules were expressed as His-tagged proteins. Protein binding assays showed an increased capacity of adsorption as a function of the number of modules, suggesting that each unit of the SBD may act in an additive or synergic way to optimize binding to raw starch.

A field trial for an ex-situ bioremediation of a drilling mud-polluted site.

The remediation of drilling mud-polluted sites in the Southeast of Mexico is a top priority for Mexican oil industry. The objective of this work was to find a technology to remediate these sites. A field trial was performed by composting in biopiles, where four 1ton soil-biopiles were established, one treatment in triplicate and one unamended biopile. Amended biopiles were added with nutrients to get a C/N/P ratio of 100/3/0.5 plus a bulking agent (straw) at a soil/straw ratio of 97/3. Moisture content was maintained around 30-35%. Results showed that, after 180 d, total petroleum hydrocarbon (TPH) concentrations decreased from 99300+/-23000mgTPHkg(-1) soil to 5500+/-770mgTPHkg(-1) for amended biopiles and to 22900+/-7800mgTPHkg(-1) for unamended biopile. An undisturbed soil control showed no change in TPH concentrations. Gas chromatographic analysis showed residual alkyl dibenzothiophene type compounds. Highest bacterial counts were observed during the first 30 d which correlated with highest TPH removal, whereas fungal count increased at the end of the experimentation period. Results suggested an important role of the straw, nutrient addition and water content in stimulating aerobic microbial activity and thus hydrocarbon removal. This finding opens an opportunity to remediate old polluted sites with recalcitrant and high TPH concentration.

Effect of melatonin treatment on oxygen consumption by rat liver mitochondria.

The objective of this study was to examine the in vivo effect of melatonin on rat mitochondrial liver respiration. Two experiments were performed: For experiment 1, adult male rats received melatonin in the drinking water (16 or 50 microg/ml) or vehicle during 45 days. For experiment 2, rats received melatonin in the drinking water (50 microg/ml) for 45 days, or the same amount for 30 days followed by a 15 day-withdrawal period. At sacrifice, a liver mitochondrial fraction was prepared and oxygen consumption was measured polarographically in the presence of excess concentration of DL-3-beta-hydroxybutyrate or L-succinate. Melatonin treatment decreased Krebs' cycle substrate-induced respiration significantly at both examined doses. The stimulation of mitochondrial respiration caused by excess concentration of substrate recovered after melatonin withdrawal. Basal state 4 respiration was not modified by melatonin. Melatonin, by curtailing overstimulation of cellular respiration caused by excess Krebs' cycle substrates, can protect the mitochondria from oxidative damage.

Comparative effects of melatonin and vitamin E in restoring aortic relaxation in pancreatectomized rats.

In a previous study we reported the efficacy of melatonin to restore the decreased relaxation response to acetylcholine (ACh) or to sodium nitroprusside (SNP) in aortic rings of rats turned hyperglycemic by subtotal pancreatectomy. The effect was amplified by pre-incubation in a high (44 mmol/l) glucose solution, a situation that resulted in oxidative stress. We hereby compare the effect of another antioxidant, vitamin E, with that of melatonin on ACh response in intact aortic rings or on SNP response in endothelium-denuded aortic rings obtained from pancreatectomized or sham-operated rats. Dose-response curves to ACh or SNP were performed in the presence or absence of melatonin or vitamin E (10-5 mol/1) in 10 or 44 mmol/1 glucose medium. Melatonin was more effective than vitamin E in restoring ACh- or SNP-induced relaxation of aortic rings in a high glucose medium. The differences between the two antioxidants may rely on the ability of melatonin to diffuse readily into intracellular compartments.

Perforaciones gastroduodenales agudas asociadas al consumo de pasta base de cocaína / Acute gastroduodenal perforations associated to cocaine consumption

Se presenta un estudio de 13 meses en 27 pacientes operados con diagnóstico de úlcera gastroduodenal perforada. En 5 de ellos hubo estrecha relación temporal entre consumo de pasta base e inicio de la perforación, constituyendo una frecuencia del 19 porciento. La edad promedio de este grupo fue de 30 años, los restantes pacientes promediaron 46 años. Los 5 pacientes presentaron intenso dolor abdominal, taquicardia y signos de irritación peritoneal. En 3 hubo indicios de neumoperitoneo. Sólo 2 pacinetes referían historia ulcerosa, en ellos la perforación se halló en la 1a. porción del duodeno; en los restantes 3, ésta se ibicó en cara anterior del antro. Todos fueron tratados mediante sutura y epiploplastía. Se postula que el efecto vasoconstrictor esplácnico agudo de la droga lleva a isquemia tisular local y perforación. En fumadores de pasta base con abdomen agudo puede existir perforación gastroduodenal a pesar de una clínica atípica de úlcera gastroduodenal perforada

Blood sugar concentrations during ketamine or pentobarbitone anesthesia in rats with or without alpha and beta adrenergic blockade.

Plasma glucose concentrations were measured in: 1) conscious and anesthetized rats during an iv glucose tolerance test (IVGTT) and 2) conscious and anaesthetized phentolamine/propranolol blocked rats during an IVGTT. Anesthesia was induced with ketamine (120 mg.kg-1) or pentobarbitone (60 mg.kg-1) ip at -30 min of the beginning of the IVGTT, which was followed by 2 injections of the anesthetic agents at intervals of 30 min. Propranolol (2 mg.kg-1) was given ip at -25 and -5 min. An iv infusion of phentolamine (0.015 mg.min-1) was started at -20 min and continued up to the end of the experiment. During the IVGTT, the anesthetized rats showed a moderate hyperglycemic response to glucose load compared to conscious animals (ketamine: p < 0.01 at 5 min; and p < 0.05 at 10-20 min; pentobarbitone: p < 0.05 at 5-20 min). The hyperglycemic response to glucose administration in the conscious rats was not affected by adrenergic blockade (p > 0.05). While in ketamine anesthetized rats the increased glucose response was abolished by adrenergic blockade (p < 0.05 at 5-10 min), this effect was not seen in pentobarbitone anesthetized animals. These results suggest the existence of an inhibitory tone on insulin secretion and a glycogenolytic response in ketamine anesthetized rats, probably mediated by adrenergic inervation of the pancreas and liver and by circulating catecholamines secreted from the adrenal medulla.

Blood sugar concentrations during ketamine or pentobarbitone anesthesia in rats with or without alpha and beta adrenergic blockade.

Plasma glucose concentrations were measured in: 1) conscious and anesthetized rats during an iv glucose tolerance test (IVGTT) and 2) conscious and anaesthetized phentolamine/propranolol blocked rats during an IVGTT. Anesthesia was induced with ketamine (120 mg.kg-1) or pentobarbitone (60 mg.kg-1) ip at -30 min of the beginning of the IVGTT, which was followed by 2 injections of the anesthetic agents at intervals of 30 min. Propranolol (2 mg.kg-1) was given ip at -25 and -5 min. An iv infusion of phentolamine (0.015 mg.min-1) was started at -20 min and continued up to the end of the experiment. During the IVGTT, the anesthetized rats showed a moderate hyperglycemic response to glucose load compared to conscious animals (ketamine: p < 0.01 at 5 min; and p < 0.05 at 10-20 min; pentobarbitone: p < 0.05 at 5-20 min). The hyperglycemic response to glucose administration in the conscious rats was not affected by adrenergic blockade (p > 0.05). While in ketamine anesthetized rats the increased glucose response was abolished by adrenergic blockade (p < 0.05 at 5-10 min), this effect was not seen in pentobarbitone anesthetized animals. These results suggest the existence of an inhibitory tone on insulin secretion and a glycogenolytic response in ketamine anesthetized rats, probably mediated by adrenergic inervation of the pancreas and liver and by circulating catecholamines secreted from the adrenal medulla.

Adrenocorticotrophic hormone, cortisol and catecholamine concentrations during insulin hypoglycaemia in dogs anaesthetized with thiopentone.

Glucose homeostasis is maintained by complex neuroendocrine control mechanisms. Increases in plasma concentrations of various glucose-raising hormones such as glucagon, catecholamines, adrenocorticotrophic hormone (ACTH), and cortisol are observed under certain conditions associated with stress (haemorrhage and hypoglycaemia). The purpose of this study was to determine the effect of thiopentone anaesthesia on the catecholamine, ACTH and cortisol response to insulin hypoglycaemia in dogs. Blood sugar (BS), plasma catecholamine, and ACTH, and serum cortisol concentrations were measured during the course of (1) an intravenous insulin test (ITT) and (2) an ACTH test in conscious and in anaesthetized fasted dogs. During the ITT, the anaesthetized dogs showed a moderate resistance, compared with conscious dogs, to the hypoglycaemic action induced by insulin (blood sugar concentration 30 min after insulin injection: 2.91 +/- 0.25 vs 1.93 +/- 0.12 mM.L-1; P < 0.01). In addition, decreased epinephrine (220 +/- 27 vs 332 +/- 32 pg.ml-1), ACTH (65 +/- 6 vs 90 +/- 5 pg.ml-1) and cortisol (4.48 +/- 0.3 vs 6.25 +/- 0.5 micrograms.ml-1) concentrations were detected 60 min after insulin injection (P < 0.01). The norepinephrine response to hypoglycaemia was not altered by anaesthesia (273 +/- 33 vs 325 +/- 25 pg.ml-1). Anaesthetized dogs showed a decreased cortisol response to ACTH at 45 min (5.68 +/- 0.54 vs 8.87 +/- 0.47 micrograms.ml-1) when compared with control dogs (P < 0.001). Haemodynamic variables during anaesthesia showed little changes (P < NS); while respiratory rate was altered (P < 0.01 between 60 and 105 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood sugar, serum insulin and serum non-esterified fatty acid levels during thiopentone anaesthesia in dogs.

The purpose of this study was to determine the effect of thiopentone anaesthesia on glucose metabolism. Blood sugar (BS), serum immunoreactive insulin (IRI) and serum non-esterified fatty acid (NEFA) concentrations were measured during the course of (1) an intravenous glucose tolerance test (IVGTT), and (2) an intravenous insulin test (ITT), in conscious and anaesthetized fasted dogs. The IVGTTs were repeated in dogs under alpha- or beta-adrenergic blockade, induced by phentolamine or propranolol. During the IVGTT, the anaesthetized dogs showed glucose intolerance (blood sugar levels were higher than in the control group) and little serum IRI response to hyperglycaemia was detected. An attenuated initial decrease and a slower rebound of NEFA concentration was observed in anaesthetized animals than in controls. Phentolamine administration (5 mg.kg-1 iv) partly restored the IRI response without affecting the BS levels; propanolol (1 mg.kg-1 iv) had no effect. Anaesthetized dogs showed a moderate resistance to insulin induced hypoglycaemic action and a lack of serum NEFA response during counter-regulation of hypoglycaemia, while in conscious controls an intense rebound was observed. Hyperinsulinaemia after iv insulin administration was longer in anaesthetized dogs than in controls. The insulin distribution space was 78% of body weight and insulin t1/2 in blood group compared with 54% and 16 min, in controls. We conclude that thiopentone provokes disturbances in glucose and serum NEFA metabolisms and abolishes the serum IRI response to hyperglycaemia. These effects are influenced by extrapancreatic factors regulating serum IRI levels and by an alpha-adrenergic mechanism, via the inhibition of insulin secretion.

Prevalence of urogenital Chlamydia trachomatis infection in El Salvador. II. Gynaecology outpatients.

The prevalence of urogenital infection caused by Chlamydia trachomatis was examined in 100 non-pregnant women with cervicitis, and 100 healthy women, in San Salvador City, El Salvador. Pharmacia Chlamydia EIA test was used for the detection of chlamydial antigen in urethral and cervical specimens from all the women. Direct immunofluorescence was used for confirmative tests on the EIA positive and the negative gray zone samples. C. trachomatis antigen was detected in 28% of the women with cervicitis compared with 5% in the group of healthy women (P < 0.001). The cervicitis group were also screened for Neisseria gonorrhoeae which was isolated from 12% of them. One strain out of 12 was beta-lactamase producing (PPNG). Five per cent of the women with cervicitis had simultaneous C. trachomatis and N. gonorrhoeae infections.

Predictors of repeat pregnancy outcome among black and Puerto Rican adolescent mothers.

This prospective study investigated predictors of repeat pregnancies by 12 months after the delivery of a first child and their outcomes in inner-city adolescent mothers. The sample included four groups: those who had therapeutic abortions, miscarriages, full-term deliveries, and no repeat pregnancy. The therapeutic abortion group had more pregnancies before their first delivery (41%) than did full term (20%) and no repeat (15%), p less than .01. More delayed grade placement was found in therapeutic abortion -1.6 years (1.3) and full term -1.8 years (.9) than in no repeat pregnancy -.6 years (1.1), p less .001. Reading achievement scores were higher in no repeat 86.3 (17.1) than in full term 75.0 (16.5), p less than .05. School attendance was higher in no repeat (65%) than in therapeutic abortion (35%) and full-term (24%) p less than .01 groups. Depressive symptoms at baseline were higher among therapeutic aborters 18.9 (9.9) than among full term 10.2 (8.2) and no repeat pregnancy groups 12.2 (6.2). Logistic regression analyses identified delayed grade placement as the most important predictor of pregnancy outcome.

PIP: The purpose of this prospective study of 120 black and Puerto Rican adolescent mothers recruited from an urban adolescent health center was 1) to identify multiple predictors of repeat pregnancies and their outcomes, and 2) to assess the relative contribution of these predictors to repeat pregnancies. Variables include demographic factors, frequency of sexual activity, contraceptive method used, occurrence of pregnancies before the first delivery, educational attainment, and levels of depressive symptoms by 3 weeks postpartum. Pregnancy outcomes included mothers who terminated their pregnancy, who delivered a live birth, and who had a miscarriage; data were available 12 months postpartum. The mean age was 17.13 years. 52% were black and 44% were Puerto Rican and of low socioeconomic status. Reliability of self-reports was 95%. 60.3% had no repeat pregnancy and 39.6% became pregnant during the 1-year followup, of which 15.3% had a therapeutic abortion, 6.3% miscarried, and 18.1% carried to term. There were no significant differences in the characteristics of the repeat and nonrepeat pregnancy groups. The procedure involved interviews at 2-4 weeks (time 1), 6-7 months (time 2), and 12-13 months (time 3). Measures for delayed grade placement, reading achievement, career aspirations and socioeconomic status of the family, and school attendance are described. Multivariate analysis, univariate analyses, and Duncan multiple range tests were conducted as well as logistic regression model construction. The significant predictors of pregnancy outcome (repeat pregnancy) were having 2 or more previous pregnancies. The abortion group was twice as likely to have had a pregnancy before the birth of the first child (41%) than the full-term (20%) and the no-repeat groups (15%). There were no differences in frequency of sexual activity or contraceptive method used. In the no-repeat and miscarriage groups, grade placement was less delayed. In the no-repeat group, reading achievement scores were higher than in the full-term group. There were no differences in career aspirations. 65% of the no-repeat group were attending school at time 2 while only 35% of the therapeutic and 24% of the full-term groups were attending school. Depressive scores were significantly higher for the abortion group. Delayed grade placement was the only predictor independently associated with the increased log odds of repeat pregnancy.

[Cardiovascular effects of ketamine anesthesia in rats treated with enalapril and propranolol]. / Efectos cardiocirculatorios de la anestesia con ketamina en ratas tratadas con enalapril y propranolol.

It is well-known that ketamine (Kt) anaesthesia produces a rise in blood pressure and heart rate in man. These cardiostimulatory effects were adscribed to several factors such as: a) increased sympathetic nervous system activity by direct stimulation of central nervous structures, b) increased catecholamine release from the peripheral sympathetic system, c) high plasmatic renin levels. However, the quantitative participation of these mechanisms in the cardiovascular effects of this anaesthetic agent is unknown. While some authors have shown a major rise in serum renin activity in experimental anaesthesia, others have been unable to confirm these results. The present study was undertaken to assess if the cardiostimulatory effects of Kt anaesthesia were due to an activation of renin-angiotensin system or to increased sympathetic activity. In consequence we used rats treated with enalapril (an angiotensin-converting enzyme inhibitor) or propranolol prior to anaesthetic procedures. Thirty male Wistar and six spontaneously hypertensive rats (SHR) weighing 240-300 g were used in all the experiments. The rats were randomly grouped into six groups. I- Non-anaesthetized rats, II- Anaesthetized rats (trained in the experimental procedures), III- Anaesthetized rats (without training), IV- Anaesthetized rats previously treated with enalapril, V- Anaesthetized rats pretreated with propranolol, VI- SHR treated with enalapril. The rats of groups IV and VI received enalapril p.o. for three weeks (25 mg/Kg body wt). The animals of group V were submitted to acute beta-adrenergic blockade. Propranolol dose: 10 mg/Kg body wt, was given i.p. 15 min before Kt anaesthesia. Blood pressure and heart rate were measured with a sphygmomanometer and photoelectric sensors and recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of urogenital Chlamydia trachomatis infection in El Salvador. I. Infection during pregnancy and perinatal transmission.

One-hundred and twenty-nine pregnant women in labour (age range 15-46 years; median age 23) and 42 infants born to chlamydia-positive mothers (age range 5-15 days; median age 10) were investigated to estimate the prevalence and incidence, respectively, of Chlamydia trachomatis infection in San Salvador, El Salvador. Urethral and cervical samples were obtained from all women and conjunctival specimens were taken from both eyes of each child. The chlamydial antigen was detected with the commercial Pharmacia Chlamydia EIA kit. Direct immunofluorescence (DFA) (Syva MicroTrak) was used for confirmation. In the newborns both EIA and DFA tests on direct preparations from ocular smears were performed on all the samples. The prevalence of chlamydial infection in pregnant women was 44% (57/129). The incidence of chlamydial infection in neonates was 64% (27/42), and the majority of the infected children (56%) had conjunctivitis. Referring to individuals rather than specimens the sensitivity of EIA tests on conjunctival samples from the infants was low (37%) as compared with 91% on urethral and cervical specimens from the pregnant women.

Efectos cardiocirculatorios de la anestesia con ketamina en ratas tratadas con enalapril y propranolol. / [Cardiovascular effects of ketamine anesthesia in rats treated with enalapril and propranolol]

It is well-known that ketamine (Kt) anaesthesia produces a rise in blood pressure and heart rate in man. These cardiostimulatory effects were adscribed to several factors such as: a) increased sympathetic nervous system activity by direct stimulation of central nervous structures, b) increased catecholamine release from the peripheral sympathetic system, c) high plasmatic renin levels. However, the quantitative participation of these mechanisms in the cardiovascular effects of this anaesthetic agent is unknown. While some authors have shown a major rise in serum renin activity in experimental anaesthesia, others have been unable to confirm these results. The present study was undertaken to assess if the cardiostimulatory effects of Kt anaesthesia were due to an activation of renin-angiotensin system or to increased sympathetic activity. In consequence we used rats treated with enalapril (an angiotensin-converting enzyme inhibitor) or propranolol prior to anaesthetic procedures. Thirty male Wistar and six spontaneously hypertensive rats (SHR) weighing 240-300 g were used in all the experiments. The rats were randomly grouped into six groups. I- Non-anaesthetized rats, II- Anaesthetized rats (trained in the experimental procedures), III- Anaesthetized rats (without training), IV- Anaesthetized rats previously treated with enalapril, V- Anaesthetized rats pretreated with propranolol, VI- SHR treated with enalapril. The rats of groups IV and VI received enalapril p.o. for three weeks (25 mg/Kg body wt). The animals of group V were submitted to acute beta-adrenergic blockade. Propranolol dose: 10 mg/Kg body wt, was given i.p. 15 min before Kt anaesthesia. Blood pressure and heart rate were measured with a sphygmomanometer and photoelectric sensors and recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Efectos cardiocirculatorios de la anestesia con ketamina en ratas tratadas con enalapril y propranolol. / [Cardiovascular effects of ketamine anesthesia in rats treated with enalapril and propranolol]

It is well-known that ketamine (Kt) anaesthesia produces a rise in blood pressure and heart rate in man. These cardiostimulatory effects were adscribed to several factors such as: a) increased sympathetic nervous system activity by direct stimulation of central nervous structures, b) increased catecholamine release from the peripheral sympathetic system, c) high plasmatic renin levels. However, the quantitative participation of these mechanisms in the cardiovascular effects of this anaesthetic agent is unknown. While some authors have shown a major rise in serum renin activity in experimental anaesthesia, others have been unable to confirm these results. The present study was undertaken to assess if the cardiostimulatory effects of Kt anaesthesia were due to an activation of renin-angiotensin system or to increased sympathetic activity. In consequence we used rats treated with enalapril (an angiotensin-converting enzyme inhibitor) or propranolol prior to anaesthetic procedures. Thirty male Wistar and six spontaneously hypertensive rats (SHR) weighing 240-300 g were used in all the experiments. The rats were randomly grouped into six groups. I- Non-anaesthetized rats, II- Anaesthetized rats (trained in the experimental procedures), III- Anaesthetized rats (without training), IV- Anaesthetized rats previously treated with enalapril, V- Anaesthetized rats pretreated with propranolol, VI- SHR treated with enalapril. The rats of groups IV and VI received enalapril p.o. for three weeks (25 mg/Kg body wt). The animals of group V were submitted to acute beta-adrenergic blockade. Propranolol dose: 10 mg/Kg body wt, was given i.p. 15 min before Kt anaesthesia. Blood pressure and heart rate were measured with a sphygmomanometer and photoelectric sensors and recorded.(ABSTRACT TRUNCATED AT 250 WORDS)