Evaluation of the protective effect of thiamine pyrophosphate based on the biochemical analysis of rabbit foetuses at 30 days of gestation.

This study evaluated the effects of thiamine pyrophosphate (PPT) on the biochemical profiles of full-term rabbit foetuses that were subjected to experimental ischemia followed by 24h reperfusion. A total of 16 gestating rabbit dams were divided into two groups, one of which was treated by administering PPT and subjected to a process ischemia. During this interval, fetal blood samples were drawn from each dam (in the ischemia group) at 0, 15 and 45min. Ischemia for 15 and 45min was not associated with changes in lactate levels of the Ischemia group foetuses. However, in the foetuses in the reperfusion groups without PPT lactate levels were significantly higher after 15 and 45min of arterial occlusion compared to time zero. These results demonstrate that PTT alters some acute and some longer-term biochemical outcomes of uterine ischemia perhaps important in preserving energy metabolism under hypoxic conditions.

The selective inhibition of the D1 dopamine receptor results in an increase of metabolized dopamine in the rat striatum.

Our aim was to study the specific role of the postsynaptic D(1) receptors on dopaminergic response and analyze the metabolized dopamine (DA) in the rat striatum. We used male Wistar rats to evaluate the effects of different doses of a D(1) agonist (SKF-38393) and a D(1) antagonist (SCH-23390), and their co-administration. The levels of DA and L-3, 4-dihydroxyphenylacetic acid (DOPAC) were measured using high performance liquid chromatography. The systemic injection of SKF-38393 alone at 1, 5 and 10 mg/kg did not alter the DA and DOPAC levels or the DOPAC/DA ratio. In contrast, injection of SCH-23390 alone at 0.25, 0.5 and 1 mg/kg significantly increased the DA and DOPAC levels, as well as the DOPAC/DA ratio, compared with the respective control groups. The co-administration of SCH-23390+SKF-38393 did not alter the DA or DOPAC levels, but it did significantly inhibit the SCH-23390-induced increase of the DA and DOPAC levels. The SCH-23390+SKF-38393 and the SCH-23390-only groups showed an increase in the DOPAC/DA ratio. The co-administration of SCH-23390+PARGYLINE significantly decreased the DOPAC levels and the DOPAC/DA ratio compared with the control and SCH-23390 groups. Taken together, our results showed that selective inhibition with SCH-23390 produced an increase in metabolized DA via striatal monoamine oxidase. These findings also contribute to the understanding of the role of postsynaptic D(1) receptors in the long-loop negative feedback system in the rat striatum.

Vetrabutine clorhydrate use in dystocic farrowings minimizes hemodynamic sequels in piglets.

The objective was to measure the effects of VC (a uterotonic drug with vasodilator effects) in eutocic and dystocic sows, on the acid-base balance and some vitality traits of piglets at birth. Farrowing was induced with prostaglandin F2α. Four groups of sows (20 sows/group) were monitored; Groups 1 and 2 were eutocic sows, whereas Groups 3 and 4 were dam-fetal dystocic sows. Groups 1 and 3 (control) were given saline, whereas Groups 2 and 4 were given VC im (1.66 mg/kg of body weight) after the first piglet was born. Piglets' physio-metabolic performance was monitored peripartum. Treatment with VC reduced (P<0.0001) the percentage of intrapartum stillbirths in sows either with eutocic (5.2 vs. 10.0%) and dystocic (7.6 vs. 16.7%) farrowings and increased (P<0.0001) the number of pigs born alive without any evidence of AFS (89.9 vs. 79.9%, eutocic and 81.6 vs. 65.2%, dystocic). In addition, for the group of pigs with no acute fetal suffering (AFS), VC treatment enhanced survival responses with a half point grater vitality score in Group 4; it also reduced the latency to first teat contact by 6 min (P<0.05) in both treated groups compared to controls; and it improved the condition of the pigs' umbilical cord, with more adhered (98 vs. 86% in eutocic and 88 vs. 80% in dystocic; P<0.05) and less ruptured cords. Moreover, VC reduced the severity of adverse physio-metabolic indicators and the acid-base balance of piglets with AFS at birth by lowering blood lactate (89.8 vs. 93.5 mmol/L in eutocic groups and 94.6 vs. 100.2 mmol/L in dystocic groups; P<0.05), PaCO2 and Ca2+, and by increasing blood pH, HCO3 and PaO2 levels (P<0.05).

Effects of long distance transportation and CO2 stunning on critical blood values in pigs.

The aim of the study was to evaluate the effect of two stressful stimuli, long transportation and 80% CO(2) stunning on metabolic-physiological variables, hemodynamic and gas exchange in slaughter pigs imported from the U.S. to Mexico City with a journey time of 27 h, with 8 h of lairage at the abattoir. A total of 589 pigs from three genders were monitored. Overall results show that both stimuli caused metabolic and physiological disturbance. Gilts were more efficient in controlling glycemia after a long transport journey (24h), than castrated males (P<0.05), whose glucose was increased above the 30 mg/dL basal level. Females on arrival had 23mg/dL more lactate compared to basal levels (P<0.05). Stunning caused more physiological effects compared to transportation. Regarding the gender factor, females and entire males were more susceptible to transport stress and stunning compared to the castrated pigs, and entire males showed more complications restoring the gas exchange compared to females and barrows.

Changes in blood constituents of swine transported for 8 or 16 h to an Abattoir.

The effects of two transportation periods on physio- metabolic hemodynamic changes and gaseous exchange in commercial swine during transportation to the slaughterhouse was studied in 684 pigs, 357 barrows and 327 gilts, transported in 2 groups for 8 and 16 h. Transportation caused an increase of oxygen consumption and body temperature, a decrease in pH, lactic acid accumulation. Both transportation periods caused higher than normal plasma glucose levels, lactic acidosis and evidence of dehydration. The linear regression analysis for pigs transported for 8h indicates that the PO(2,) lactate and Ca(++) variables correlated negatively with the PCO(2.) Whilst the animals that were transported for 16 h had negative correlations between glucose, and calcium, hematocrit, lactate and potassium levels. It was concluded that regardless of transport time acidosis, hypocapnia, hypoxaemia, hypernatraemia, hypercalcaemia, hyperglycemia, lactacidemia and increased hematocrit levels occurred.

Uterine activity and fetal electronic monitoring in parturient sows treated with vetrabutin chlorhydrate.

The aims of the study were to characterize the uterine activity in sows treated with vetrabutin chlorhydrate (VC), an uterotonic and muscle-tropic drug during farrowing, and to measure the effects of the drug on piglet neonatal viability. The experiment involved 1478 piglets from 130 Yorkshire-Landrace sows, randomly allotted into two groups. Farrowing monitoring began 12 h after PGF2alpha synchronization. Group 1 was given physiological solution (G1, n = 65); Group 2 was treated with VC (1 mL/60 kg LW) at the initiation of fetal expulsion (G2, n = 65). In spite of the total duration of expulsion being significantly longer (P < 0.0001), approximately 35 min in the VC treatment, VC application at the time the first piglet was expulsed favored the alive birth of at least one more piglet. Even though the pressure in the uterus was similar in both groups, the number and duration of uterus contractions recorded were significantly less (P < 0.0001) in G2, favoring fewer births with acute fetal suffering, compared with that in G1. VC treated group compared with the control group also had fewer (5.01% vs. 24%) alterations in umbilical cords, as well as a lesser incidence of secondary apnea (2.08% vs. 7.46%) and bradycardia (1.94% vs. 7.61%), which favored a significantly higher vitality score (P < 0.002). With the intent to evaluate uterine activity in sows during the farrowing process, we propose using the equation used in human medical practices to calculate Montevideo Units applied to swine obstetrics for the first time.

CO(2) stunning may compromise swine welfare compared with electrical stunning.

The effects of two different stunning methods on critical blood values in fattening pigs at a federal inspection slaughtering plant were monitored. A total of 658 pigs from the same genetic line and origin, were randomly assigned to 3 treatments: reference baseline levels (resting pigs; T1), stunning with CO(2) (T2) and stunned electrically (T3). Energetic profile, acid imbalance and blood gas levels, were monitored. Significant differences (p⩽0.05) between treatments for all variables were found, CO(2) stunned pigs showed hypercapnia, hypercalcemia, hyperglucemia, lactic acidemia, and an increase in haematocrit, coupled with reduced pH, [Formula: see text] , and Na; electrically stunned pigs had reduced blood pH, [Formula: see text] and [Formula: see text] . The remaining indicators were increased in relation to the resting swine. Thus CO(2) stunning leads to a major imbalance because of mineral and acid base gaseous interchange, compared to electric stunning, thus possibly compromising animal welfare.

Short-term neurophysiologic consequences of intrapartum asphyxia in piglets born by spontaneous parturition.

Piglets appear to be neurologically sensitive to intrapartum asphyxia. Our aim was to investigate the short-term neurophysiologic consequences of intrapartum asphyxia in piglets. We studied 10 piglets suffering intrapartum asphyxia and 10 control piglets. Glucose and blood gas levels, tympanic membrane temperature, and body weight were measured within the first 2 min after birth. Animals were followed up for a 5-day period. As surrogated markers of piglets' neurological function, a viability score and the time elapsed from birth to the first contact with the maternal udder were recorded. In the control group, temperature and blood pH levels at birth were significantly higher (p < or = .001), whereas calcium, lactate and PCO2 levels were statistically lower (p < or = .05) than in the piglets experiencing intrapartum asphyxia. Lower temperature and blood pH levels as well as higher blood PCO2 and lactate levels were observed in piglets with lower viability scores and in piglets with prolonged times until first udder contact. At the end of the study, asphyxiated piglets weighed on average 200 g less (p = .023) than control piglets. In conclusion, intrapartum asphyxia in spontaneously born piglets was associated with signs of acute neurological dysfunction and lower weight gain, supporting the hypothesis that they may be used as a naturalistic model for the study of asphyxia in newborns.

A systematic review of experimental and clinical studies of sildenafil citrate for intrauterine growth restriction and pre-term labour.

Sildenafil could be an alternative in the treatment of intrauterine growth retardation (IUGR) and premature delivery. In order to systematically review the reproductive-related effects of sildenafil, a search was made on PubMed and the Science Citation Index for studies evaluating the effects of sildenafil on uterine vessels or myometrium either in vitro or in experimental animal models as well as for any clinical trial or case reporting the outcome of pregnant women treated with sildenafil. The information was obtained from: three in vitro studies, five studies performed in experimental animal models, four studies on women with fertility and sterility disorders receiving 100 mg/day of sildenafil intravaginally, and two case reports of pregnant women who received sildenafil for the treatment of pulmonary hypertension. Incubation with sildenafil of different in vitro preparations resulted in vasodilator and uterine relaxant effects. No evidence of teratogenicity was observed in the studies performed in mice, rats and dogs. Sildenafil increased fetal weight in rats. In women, contradictory results on uterine blood flow and endometrial development were reported after the intravaginal administration of sildenafil. No adverse fetal outcomes were reported in the two pregnant women with pulmonary hypertension receiving sildenafil late in their pregnancy. In conclusion, there is still limited information about the efficacy of sildenafil for the treatment of IUGR and premature delivery. However, studies in experimental animal models and two human case reports have reported no deleterious effects on the mother or offspring.

Effect of pentobarbital on pH and electrolyte levels after induced seizure in rats.

We studied the effects of high doses of pentobarbital (PB) and carbamazepine (CBZ) on electrolyte levels and pH in an epileptic animal model. Pentobarbital decreased Ca2+ and Na+ levels without pentylenetetrazole (PTZ). After this, Ca2+ and Na+ levels continued to decrease except when CBZ was used, which preserved the Ca2+ levels PTZ may have opposed effects on PB. Our results suggest that PB causes changes in electrolyte levels and pH, but these changes are diminished by CBZ.

Effects of mid-summer transport duration on pre- and post-slaughter performance and pork quality in Mexico.

Seven hundred and fourteen pigs were monitored from transport to slaughter in July in three treatments: 8, 16 and 24 transport hours; lairage time for the three groups was of 8h. Transport duration significantly (P<0.05) affected live-weight gain during the rest period. Weight gain percentages at lairage were 0.05%, 0.78% and 1.15% for treatments 1, 2 and 3, respectively. Transport to slaughter loss percentage was 2.7%, 4.3% and 6.8% for each of the treatments. Short transport periods significantly increased carcass pH below normal values. Animals transported under acute stress (8h) showed pale carcasses (high possibilities of transforming into PSE meat). On the contrary, pigs transported for 24h had more dark red carcasses. Transport from farm to the slaughterhouse should take no more than 16h in order to improve carcass quality and animals' welfare.

The effects of vetrabutin chlorhydrate and oxytocin on stillbirth rate and asphyxia in swine.

Oxytocin and vetrabutin chlorhydrate (VC) are used to reduce the duration of farrowing in swine. The objective of the present study was to evaluate the use of these products on intra-partum stillbirth (IPS) rate and asphyxia. At the onset of parturition, sows (n=180) were allocated to receive 2 mL of saline (control group), oxytocin (40 IU i.m.) or 100mg of VC per 60 kg of body weight, with all treatments given i.m. Oytocin-treated sows had a higher number of IPS than the VC and Control groups (means, 1.2, 0.8 and 0.6, respectively; P<0.001), and the highest percentage of ruptured umbilical cords (76.0, 9.4 and 37.5%; P<0.003). There were differences among groups for duration of farrowing (means, 163.0, 211.2 and 306.9 min in the oxytocin, VC and control groups; P<0.001), interval between piglets (13.9, 19.2 and 28.1 min; P<0.001), and in IPS, the incidence of ruptured umbilical cords was 76.0, 9.4 and 37.5% (P<0.003) and absence of a fetal heartbeat was 53.3, 16.9 and 12.5% (P<0.05). Although oxytocin decreased both duration of farrowing and interval between piglets by approximately 50% relative to control sows, it resulted in a significantly higher rate of IPS, in association with a much higher incidence of ruptured umbilical cord and absence of a fetal heartbeat. Treatment with VC reduced farrowing duration by approximately 1.5h, with an IPS rate that was not significantly different from controls but significantly lower than that of oxytocin-treated sows.