Surface transformation of ram spermatozoa in uterine, oviduct and cauda epididymal fluids in vitro

Genital tract fluids were collected continuously from conscious ewes through catheters inserted surgically into the uterus and oviducts. Cauda epididymal spermatozoa and fluid were obtained through catheters inserted into the transected vas deferens. The washed spermatozoa were labelled using the surface-specific chloroglycoluril-Na125I procedure. High-resolution electrophoretic analysis of sperm plasma membrane preparations revealed a partial loss of a major surface component (i.e. Mr 97,000) during incubation in uterine and oviduct fluids. This specific loss resulted in a shift in radioactivity distribution toward an Mr 24,000 component which had been previously identified as a sialoglycoprotein. No significant changes in the distribution of radiolabelled surface components were detectable when the spermatozoa were incubated in synthetic medium. Incubation of unlabelled spermatozoa in 125I-labelled uterine fluid showed that adsorption of exogenous fluid components was highly selective; an Mr 16,000 polypeptide was greatly enriched on the sperm surface although it was only a minor component in the incubation fluid. Adsorption of labelled oviduct fluid components was also selective and involved predominantly high molecular weight components (i.e. Mr 140,000, 95,000, 78,000, 53,000). When spermatozoa were incubated in labelled cauda epididymal fluid after exposure to unlabelled uterine and oviduct fluids, several fluid components were incorporated by the plasma membrane, indicating that surface renovation of 'capacitated' spermatozoa may be a more general process rather than a specific event. These results suggest that capacitation of ram spermatozoa involves loss of specific surface proteins as well as selective adsorption of exogenous fluid components and point to a polypeptide in uterine fluid as an active constituent.     

Sequential uterine horn versus simultaneous total uterine flush to recover bovine embryos nonsurgically

Beef cows were superovulated with follicle stimulating hormone (FSH) to compare two nonsurgical methods of embryo recovery from the uterus. In the first method each uterine horn was independently flushed with physiological saline solution (PSS) through a Foley catheter passed through the cervix and into the uterine horn. In the second method both uterine horns were simultaneously flushed with PSS by passing the catheter into the uterine body. In both methods, the numbers of ovulations were determined after embryo collection by counting the corpora lutea (CL) on both ovaries of each cow through a flank incision. Independent flushing (n = 19) averaged 6.4 embryos and 16.1 CL per cow for a recovery rate of 40%. Simultaneous flushings (n = 22) averaged 5.4 embryos and 17.7 CL per cow for a recovery rate of 31%. This difference between the recovery rates of the two flushing methods was not significant (P>0.05).     

Femoral Arterial and Venous Catheterization for Blood Sampling,Drug Administration and Conscious Blood Pressure and Heart Rate Measurements

In multiple fields of study, access to the circulatory system in laboratory studies is necessary. Pharmacological studies in rats using chronically implanted catheters permit a researcher to effectively and humanely administer substances, perform repeated blood sampling and assists in conscious direct measurements of blood pressure and heart rate. Once the catheter is implanted long-term sampling is possible. Patency and catheter life depends on multiple factors including the lock solution used, flushing regimen and catheter material. This video will demonstrate the methodology of femoral artery and venous catheterization of the rat. In addition the video will demonstrate the use of the femoral venous and arterial catheters for blood sampling, drug administration and use of the arterial catheter in taking measurements of blood pressure and heart rate in a conscious freely-moving rat. A tether and harness attached to a swivel system will allow the animal to be housed and have samples taken by the researcher with minimal disruption to the animal. To maintain patency of the catheter, careful daily maintenance of the catheter is required using lock solution (100 U/ml heparinized saline), machine-ground blunt tip syringe needles and the use of syringe filters to minimize potential contamination. With careful aseptic surgical techniques, proper catheter materials and careful catheter maintenance techniques, it is possible to sustain patent catheters and healthy animals for long periods of time (several weeks).     

Rapid Absorption and Local Redistribution of Progesterone after Vaginal Application in Gilts

Catheters were implanted in 6 anaesthetized gilts (3 animals in the follicular phase, 3 in the luteal phase) into a carotid artery and into the utero-ovarian vein and uterine artery on both sides. The uterine lumina were closed by a suture. Further, a catheter was inserted into the vagina after which the animals were allowed to recover. Tritiated progesterone was infused into vagina the following day during a 2 min period and simultaneous blood samples collected from the 5 catheters every 10 min for 2 h after which the animals were sacrificed. Tissue samples were obtained from the genital organs. The results showed a rapid absorption of progesterone from the vaginal lumen and a marked redistribution to the genital organs. The increased level of radioactivity in the plasma samples collected from the uterine arteries compared to the simultaneous samples from the carotid artery in 2 of the 3 animals in the luteal phase indicates the existence of a local redistribution system.     

Simple cannulation procedure for serial blood sampling through cutaneous ulnar vein in chickens

The objective of the study was to collect repeated, low-stress blood samples from the ulnar vein of chickens required for pharmacokinetic studies or hormonal assays. The study used 5 apparently healthy, unsexed, commercial broiler chickens about 6 weeks old and weighing 1.7-1.9 kg for serial sampling of blood. The study prepared the birds prior to cannulation and penetrated the catheter through the skin and into the lumen of the ulnar vein. The study successfully carried out serial blood samplings in 4 of 5 cannulated birds. Heparin (10%) solution maintained patency and prevented blood clot formation inside the cannula. However, the study found repeated clotting occurring in 1 bird. Cannula failed to maintain patency; the study could not carry out blood sampling properly, which was attributed to air embolism that might have occurred during catheter manipulation or repeated filling of cannula with heparin solution. The study observed no hematoma or inflammation at the site of cannulation. Owing to the advantages and to facilitate compliance with nonhuman animal welfare, this technique seems simple and efficient, allowing adoption for serial blood collection in chickens.     

Simple Cannulation Procedure for Serial Blood Sampling Through Cutaneous Ulnar Vein in Chickens

The objective of the study was to collect repeated, low-stress blood samples from the ulnar vein of chickens required for pharmacokinetic studies or hormonal assays. The study used 5 apparently healthy, unsexed, commercial broiler chickens about 6 weeks old and weighing 1.7–1.9 kg for serial sampling of blood. The study prepared the birds prior to cannulation and penetrated the catheter through the skin and into the lumen of the ulnar vein. The study successfully carried out serial blood samplings in 4 of 5 cannulated birds. Heparin (10%) solution maintained patency and prevented blood clot formation inside the cannula. However, the study found repeated clotting occurring in 1 bird. Cannula failed to maintain patency; the study could not carry out blood sampling properly, which was attributed to air embolism that might have occurred during catheter manipulation or repeated filling of cannula with heparin solution. The study observed no hematoma or inflammation at the site of cannulation. Owing to the advantages and to facilitate compliance with nonhuman animal welfare, this technique seems simple and efficient, allowing adoption for serial blood collection in chickens.     

Radiographic contrast medium for uterine insemination in the bitch, and its effect upon the quality and fertility of fresh dog semen

Four ejaculates were collected from each of 6 adult male beagle dogs. The second fraction was divided into 3 aliquants which were then diluted with physiological saline, an isoosmolar solution of sodium/meglumine diatroate, and an iso-osmolar solution of iohexol. The diluted samples were incubated at 39 degrees C and evaluated at 0, 60, 90, 120, 240 and 360 min after dilution. A variety of assessments was made, including, spermatozoal motility, spermatozoal morphology, and acrosorne status. The practicality of using 1.0 ml of iso-osmolar contrast medium combined with radiographic examination was evaluated as a method of confirming accurate placement of a transcervical uterine catheter by injecting contrast after positioning the catheter in 4 beagle bitches. The effect of the procedure on fertility was assessed using 5 greyhound bitches which were inseminated with fresh semen and in which pregnancy was monitored using diagnostic B-mode ultrasound imaging. There was no significant difference between physiological saline and the sodium/meglumine diatroate solution upon semen quality, while the iohexol solution produced a significant reduction in spermatozoal motility and morphology. No adverse clinical effects were observed when contrast medium was administered into the uterus to either group of bitches. A subjective assessment of radiographic quality showed that the sodium/meglumine diatroate solution, which contained twice the iodine concentration of the iohexol solution, produced significantly greater radiopacity and was radiographically more useful than the iohexol solution. The sodium/meglurnine diatroate solution had no adverse effect upon the fertility of dog semen, and all bitches that were inseminated with this technique conceived and maintained the pregnancy to term. Litter size was considered to be normal for the breed. Small volumes of an iso-osmolar solution of sodium/meglumine diatroate may be useful for ensuring correct placement of transcervical catheters prior to artificial insemination in the bitch.     

Chlorine dioxide sterilization of implanted right atrial catheters in rabbits

The disinfection of right atrial catheters in situ using chlorine dioxide was investigated. Catheters were implanted into rabbits (Oryctolagus cuniculi) and colonized by inoculation of Staphylococcus aureus, Sa-80, into the lumen. All of the catheters were colonized and the difference in numbers of bacteria recovered from animals destined for the control and disinfection groups was not significant. Animals were assigned randomly to the control or disinfection group. Treatment consisted of filling the catheter lumen of the disinfection group with chlorine dioxide and of the control group with sterile physiological saline daily for 15 minutes. In addition, both groups received systemic antimicrobial therapy. Cultures of blood withdrawn from the catheters and by venipuncture were negative for five of the nine control group animals after treatment for 5 days. Four control group catheters failed, after from 3 to 21 treatments, without ever achieving negative cultures. All nine animals in the disinfection group had negative cultures after treatment for 5 days. Subsequently, one animal from each group reverted to positive cultures. All nine control group catheters failed during the study, compared to only three disinfection group catheters (p less than 0.01). At necropsy, culture of cardiac blood, thrombi and catheter tubing sections demonstrated colonization of six in the control group and only one in the disinfection group (p less than 0.05). Rabbits tolerated the chlorine dioxide disinfection well and no adverse signs were noted.     

Chronic catheterization of the inferior vena cava in Yucatan miniature swine.

Long-term venous access for leukapheresis, repeated blood sampling, and administration of drugs and fluids can be accomplished nonsurgically in Yucatan miniature swine. The catheter is placed under fluoroscopic guidance into the inferior vena cava using a needle and guidewire. This procedure has the advantage that it avoids a surgical incision, allows high flow rates, exists conveniently on the lower back, and can be replaced easily in the event of mechanical failure or thrombosis. Actuarial analysis of the duration of patency disclosed that of 41 catheters placed in 30 animals, the probability of function at 28, 42, and 54 days was 75%, 50%, and 25%, respectively. Eleven nonfunctioning catheters were replaced and nine of these continued to function until the completion of the experiment. No catheters were removed due to infection. Chronic catheterization of the inferior vena cava is a convenient method for long-term venous access in swine.     

巴氯芬注射液Beagle犬腰椎穿刺置管多次鞘内注射局部刺激性研究

目的模拟临床给药途径,Beagle犬腰椎穿刺置管多次鞘内注射巴氯芬注射液,观察其局部刺激性,同时进行犬行为学观察,为巴氯芬注射液安全性评价提供依据。方法12只Beagle犬分为假手术组,生理盐水对照组,巴氯芬给药组。行腰椎穿刺置管,使用单通道微量注射泵泵入给药,给药剂量为1000μg/d,生理盐水对照组给予生理盐水0.5mL,连续给药7d,恢复期7d。每日进行行为学观察,给药结束及恢复期结束时每组麻醉2只动物,取给药部位脊髓进行组织病理学检查。结果给药及恢复期期间动物行为未见异常,给药结束时各组均有部分动物观察到置管处表皮感染现象,进行局部消毒处理后在恢复期第3天恢复正常。组织病理学检查发现给药及恢复期结束时各组动物脊髓均可见血管周围炎细胞浸润或脊髓内钙盐沉积,各组无差别。给药结束时巴氯芬组1例动物脊膜处有肉芽组织形成,判定与置管操作有关。结论巴氯芬注射液Beagle犬腰椎穿刺置管连续7d鞘内注射,给药剂量为1000μg/d对脊髓无局部刺激性作用,动物行为也未见异常。     

Effects of atrial natriuretic factor on maternal ovine vascular resistance

Atrial natriuretic factor (ANF) is a potent endogenous vaso-dilator and diuretic peptide of uncertain physiologic relevance. In this study, the effects of ANF on normal and angiotensin II constricted placental, uterine and renal vessels were examined in pregnant sheep. Ewes were equipped with catheters to monitor vascular pressures, infuse drugs and measure blood flow by the microsphere technique. An electromagnetic flow sensor was placed around the middle uterine artery and electromyogram electrodes were attached to the uterus. ANF was administered into a branch of the uterine artery to minimize its systemic effects. The experiment included two protocols. First, blood flows and pressures were measured after a 5-min period of saline infusion into the uterine artery. These measurements were repeated at the end of a 5-min infusion of ANF (6.25 micrograms.min-1) into the uterine artery. During the second protocol, angiotensin II (AII) was infused via the jugular vein at 5 micrograms.min-1 for 10 min and ANF (6.25 micrograms.min-1) was infused through the uterine artery during the second half of the AII infusion. In the absence of AII, ANF lowered blood pressure from 97 +/- 6 to 90 +/- 6 mmHg (P less than 0.05); and placental resistance from 67.8 +/- 11.3 to 57.3 +/- 10.4 mmHg.min.ml-1 per g (P less than 0.01). Uterine resistance did not change.(ABSTRACT TRUNCATED AT 250 WORDS)     

A rapid and non-surgical procedure for jugular catheterization of pigs

A rapid and non-surgical method for jugular catheterization in pigs was set up in 30 piglets of 6.2 kg, 23 pigs of 46 kg and 84 kg and two lactating multiparous sows. The animal was restrained on a V-shaped table (piglets) or with a rope around the mandible (slaughter pigs and sows). The vein was located with the Vacutainer system and a wire guide was inserted into the Vacutainer needle up to the vein lumen. When the needle was removed, the catheter was inserted over the wire guide and advanced until it penetrated the skin and thereafter, the vein wall. The catheter was fixed outside by a large tape and coiled inside a patch just behind the ears. The technique utilizes readily available material and is no more risky for the animal than a single blood sampling. Moreover, it can be performed within 15 to 20 min (including animal restraint) within pens. This new approach might have important implications not only for research purposes by facilitating repeated blood samplings but also for projects which require a rapid and easy method for testing of any kind of pharmaceutical or other type of products under husbandry conditions.     

A simplified method for metabolic studies in conscious swine

Reliable short-term blood access in conscious swine was provided by implanting multiple silastic catheters. Catheters were inserted into the aorta, hepatic vein, portal vein, and inferior vena cava through a midline laparotomy incision. Multiple catheters also were placed into the external jugular vein through a separate cervical incision. Catheter patency rates for blood withdrawal on the sixth post-operative day were: arterial 100%, hepatic 91%, portal 86%, inferior vena cava 71%. No animal had major wound or catheter infection on the seventh post-operative day. The methods described allow metabolic studies, including measurements of splanchnic blood flow, to be carried out either acutely or for up to at least 7 days post-operatively.     

Implantable device for intravenous drug delivery in the rat.

The experimental design of studies using small laboratory animals may require repeated venous access for the application of drugs or diagnostics. An appropriate device should provide quick intravenous access without causing severe handling stress to the animals or the necessity of anaesthesia. In addition, the system should be suitable for repeated injections over several weeks. A silicone catheter is connected to an intravenous indwelling cannula with fixation wings. A closure stopper with injection port completes this system. The device is fixed subcutaneously on the back of the animal and the catheter is inserted into the jugular vein. The device is easily and quickly assembled and is more economic than commercial systems. It is easily implanted and allows repeated intravenous injections for several weeks without anaesthesia or restraint of the animals. The method allows repeated intravenous drug delivery over a couple of weeks in small animals.     

Ureteral catheter system for renal function studies in conscious rabbits

To overcome the problem of obstruction of ureteral catheters with blood clots, a ureteral catheter was constructed which had a double lumen. Irrigation of blood from the catheter was accomplished by perfusion of heparinized saline through a small inner catheter. In renal function studies performed in 12 rabbits using this system, no instances of catheter obstruction occurred.     

Simultaneous sampling of portal, hepatic and systemic blood during intragastric loading and tracer infusion in conscious pigs

A surgical model for catheterization at multiple sites has been developed for use in long-term metabolic studies. For blood sampling, catheters were inserted into the portal and hepatic veins and the common carotid artery. The hepatic vein catheter was inserted from the margin of a liver lobe and led through the venous system, until the tip was close to the bifurcation with the inferior vena cava. A new technique was developed to ensure correct placement of the hepatic vein catheter using the specific extraction of indocyanin-green over the liver during surgery. Gastrostomy was performed using a Pezzer catheter. Catheters in the artery and hepatic and portal veins were patent for blood withdrawal for up to 4 weeks, and thus allowed repeated metabolic studies. Studies were performed in conscious animals familiar with the experimental situation.     

Coronary artery embolization in closed-chest canines using flexible radiopaque plugs

A new technique induces localized myocardial infarction in closed-chest dogs by placing discrete plugs in coronary arteries without using cumbersome coaxial catheters or guide wires. Flexible plugs, essential to this method, are formed by extruding a dental impression polymer, rendered radiopaque with sodium iodide, into spaghetti-like strands. Segments of these strands can be injected through a catheter into a selected coronary artery. Contact with blood or saline causes plugs to swell. The mean increase in plug diameter due to swelling was 27 +/- 20%. Eight anesthetized dogs were embolized via carotid approach [6 left anterior descending (LAD), 1 left circumflex (LCX), and 1 LAD and LCX]. Plug positions were monitored fluoroscopically. One animal died at 2 days postembolization. The remaining seven dogs were killed after 14-37 days. Autopsies showed complete vessel occlusion and localized infarction. Infarcts resulting from coronary artery occlusion with one, two, or three plugs involved 2-26% of the left ventricular mass.     

Enteral perfusion in the pig

Techniques for the insertion of catheters in the colon of piglets following simple laparotomy were developed to facilitate an in vivo study of colonic absorption. Catheters were tunneled subcutaneously to a dorsal parascapular position from which the colon could be intermittently (or continuously) perfused with test solutions without physical or chemical restraint. Because of the pig's unique body habitus, the catheter is not likely to be removed by the animal. We have demonstrated in four pigs that they can be maintained free of systemic sepsis for up to 2 weeks, allowing for regular intermittent administration of fluids.     

A self-powered constant infusion device for use in unrestrained rats

We developed a device that delivers fluid through a catheter at a constant rate and can be used in conscious animals to solve a variety of problems. For example, this device can be used for delivering drugs and maintaining intravascular catheter patency. The device provides infusions at low flows (1.0-1.5 ml/day), so that experimental agents may be administered with minimal volume loading of the rat. Arterial and venous catheter patency is maintained by infusion of heparinized saline through indwelling catheters attached to the device. The catheters exit from the rat in the intrascapular area and are routed through a protective spring to the device, which is suspended above the cage. The catheters may be attached to pressure transducers, blood may be sampled, and injections or infusions may be made without disturbing the rat. Because the device is self-contained, it can be suspended by a fluid-free swivel that rotates through 360 degrees, providing minimal restraint. The device has been used successfully to measure arterial and central venous blood pressures in two studies using rats.     

An absorbable catheter system for use in microvascular and peripheral vascular surgery: an experimental study in the canine.

An absorbable catheter for use in regional anticoagulation in microvascular and peripheral vascular surgery was studied in 20 sites in 10 adult beagle dogs to answer three questions: (1) Could the polyglycolic acid and trimethylene carbonate catheter withstand intraarterial pressures of infusion and completely absorb over a predictable time interval? (2) Could the catheter be filled with heparin and maintain patency for reuse after a 24-hour interval? (3) Could the catheter be placed in a side branch of a major artery and, after catheter dissolution, maintain long-term patency of the primary feeding artery? The catheters were completely absorbed from 24 to 34 weeks following implantation. The catheters were able to withstand intraarterial pressures, and no evidence of significant thrombosis of the primary feeding artery was seen in any animal studied. No complications of catheter leak, hematoma formation within the catheter placement sites, or sepsis were noted in any of the 20 catheter sites studied.