Nonsurgical Sterilization Research Articles

Effects of intratesticular administration of zinc gluconate and dimethyl sulfoxide on clinical, endocrinological, and reproductive parameters in dogs

Nonsurgical sterilization methods are considered alternative tools for the worldwide challenge represented by canine overpopulation control. Intratesticular injection of zinc gluconate associated with DMSO arises as an option because of the effortless diffusion throughout the testicular parenchyma. This study aimed to verify the effectiveness of a double testicular injection of zinc gluconate associated with DMSO as a chemical contraceptive for male dogs. The study was conducted with 22 dogs treated with two intratesticular injections of the chemical solution (treated group; n = 15) or 0.9% NaCl solution (control group; n = 7) on a monthly interval. All animals were submitted to clinical examination, breeding soundness evaluation including morphologic and sonographic examination of the testes, assessment of libido, volume of the sperm-rich fraction, sperm motility, total sperm count, plasma membrane integrity, sperm morphologic abnormalities, and the total number of morphologically normal and motile sperm in the ejaculate. Blood samples were collected for serum testosterone analysis, and testicular tissue was morphologically and histologically evaluated. No clinical alterations and signs of pain or local sensitivity along the experimental period were noticed. However, the injection of zinc gluconate and DMSO significantly reduced libido and testosterone concentrations (even beyond the reference range for intact male dogs). Impairment of sperm quality–related variables was observed 15 days after the first intratesticular administration of zinc gluconate and DMSO (i.e., decrease in sperm count and sperm motility and an increase in major sperm defects and by this a decrease in the total number of morphologically normal and motile sperm). Testicular ultrasonographic analysis revealed reduction of testicular volume and changes of testicular echotexture in treated animals, compatible with tissue degeneration, fibrosis, and calcification of testicular parenchyma on histologic examination. In conclusion, intratesticular administration of zinc gluconate associated with DMSO reduces reproductive potential which may lead to subfertility or infertility in dogs.

A dose-finding, long-term study on the use of calcium chloride in saline solution as a method of nonsurgical sterilization in dogs: evaluation of the most effective concentration with the lowest risk.

BackgroundCanine overpopulation is a global issue with serious health and welfare implications. Nonsurgical methods of sterilization could yield positive impacts on this problem, but no long-term data on such methods are available. The objective of the current investigation was to determine the effects of intratesticular injections of calcium chloride dihydrate (CaCl2) in saline in dogs over a one year period. Five concentrations (0%, 10%, 20%, 30%, 60%) of CaCl2 in saline were administered via intratesticular injection to groups of 10 dogs each. Total sperm count and motility, blood levels of testosterone, and side effects were examined at 0, 2, 6, and 12 months post-injection (PI). Testicular size and semen volume were examined at 0 and 12 months PI.ResultsTotal sperm count, semen volume and testosterone showed significant dose-dependent decreases upon treatment with 10%-60% CaCl2 compared with either the control group (0% CaCl2) or baseline for each treatment group. Azoospermia was achieved for at least 12 months PI in 60% and 80% of treated dogs after administration of a 10% and 20% CaCl2, respectively. Treatment with 30% or 60% CaCl2 resulted in azoospermia in 100% of dogs, but more side effects were observed, while no side effects were noticed at lower doses. For each treatment group, testosterone levels had decreased an average of 35%-70% at 6 months following treatment. However, testosterone levels rebounded by the 12-month time point in all groups except the highest dosage group (60% CaCl2), which remained at the low end of physiological range throughout the study. Sperm motility dropped to zero or near zero in all dogs treated with CaCl2. Testicular size was significantly smaller at 12 months PI for all groups when compared to baseline.ConclusionsThis first long-term study confirms reports of the efficacy of CaCl2 sterilization. However, at dosages free of adverse events, calcium chloride in saline may not provide permanent sterilization as previously believed. Future work should explore optimized solvents to increase the permanence of the well-tolerated 20% formulation.

Alcohol diluent provides the optimal formulation for calcium chloride non-surgical sterilization in dogs.

BackgroundSurgical castration is widely used to sterilize male dogs, but has significant impacts on time to perform the operation, recovery of the animals as well as cost, which can limit population control programs. Previous research has shown intratesticular injection of calcium chloride dihydrate (CaCl2) in saline to be a promising alternative to surgery. However, long-term azoospermia was not maintained at dosages low enough to avoid side effects. In the search for an optimized formulation, the current investigation is the first study on long-term sterilization effects of intratesticular injection of CaCl2 in either lidocaine solution or alcohol in dogs. CaCl2 at 20% concentration in lidocaine solution or alcohol was administered via intratesticular injection to groups of 21 dogs each. The treated animals were examined at 2, 6, and 12 months for sperm production, blood levels of testosterone, and side effects; at time zero and 12 months for testicular size and semen volume. The experimentally treated animals were compared to a control group receiving saline injection only.ResultsTesticles of dogs treated with CaCl2 in either diluent significantly decreased in size. After administration of CaCl2 in lidocaine solution, sterility was achieved for at least 12 months in 75% of treated dogs. However, optimal long-term contraceptive effectiveness was achieved with CaCl2 in alcohol, which resulted in azoospermia over the 12-month study period. Testosterone levels significantly decreased following treatment with CaCl2, and sexual activity disappeared. Although testosterone returned to baseline levels by 12 months for the group treated with CaCl2 in lidocaine, dogs injected with CaCl2 in alcohol had a 63.6% drop in testosterone level, which remained at the low end of physiological range throughout the study. No adverse effects were noted.ConclusionsA single, bilateral intratesticular injection of 20% CaCl2 in 95% ethanol was a reliable method for induction of sterilization in 18–28 kg male dogs in this study. The approach showed long-term efficacy and reduced sexual behavior. This chemical method of sterilization might provide an effective, efficient alternative to surgical castration that can have positive impacts on dog welfare.

Suppression of fertility in adult cats.

Cats are animals with highly efficient reproduction, clearly pointing to a need for suppression of fertility. Although surgical contraception is highly effective, it is not always the method of choice. This is predominantly because it is cost-intensive, time-consuming and irreversible, with the latter being of major importance for cat breeders. This article reviews the use of progestins, scleroting agents, immunocontraception, melatonin, GnRH antagonists and finally, GnRH agonists, in adult male and female cats in detail, according to the present state of the art. By now, various scientific and clinical options are available for the suppression of fertility in adult cats and the decision as to which should be chosen - independent of the legal registration of any state - depends on different facts: (i) feral or privately owned animal? (ii) temporary or permanent suppression of fertility wanted/needed? (iii) sex of the animal? New effective and available methods for hormonal contraception include melatonin implants for short-term post ponement of oestrus in adult queens and slow-release GnRH-agonist implants containing deslorelin (Suprelorin(®) ) for short- and long-term contraception in male and female companion and breeding cats.

Gonadotropin‐Releasing Hormone Targeting for Gonadotroph Ablation: An Approach to Non‐surgical Sterilization

Surgical sterilization is the mainstay of dog and cat population control, but its use is still often limited by the costs and effort involved, especially in developing countries. An ideal non-surgical sterilant that is safe, effective, permanent, administered as a single injection and capable of being manufactured inexpensively could have a significant impact on the world-wide dog and cat overpopulation problem. One approach towards developing such an agent is the targeting of pituitary gonadotrophic cells with cytotoxic agents using gonadotropin-releasing hormone (GnRH). GnRH is a peptide that binds to high-affinity receptors selectively expressed on gonadotrophs and some types of cancers. Both small molecules and proteins have been conjugated to GnRH analogues to generate targeted cytotoxic and imaging agents. Although most of these efforts have focused on development of human cancer therapeutics, available reproductive studies in rats and dogs suggest that current compounds do not have sufficient therapeutic windows for complete gonadotroph ablation, in part owing to poor stability of peptide targeting sequences. The only reported longer-term study of gonadotroph ablation in dogs reported suppression of serum testosterone for 8 months, but endocrine function then recovered, raising important questions about the mechanism of reproductive suppression and its recovery. Although studies to date suggest that this is a potentially attractive approach to non-surgical sterilization, ideal agents are yet to be developed, and important mechanistic questions remain to be answered.

Pelvic surgery and hospitalization among Chilean women after nonsurgical sterilization with quinacrine pellets between 1977 and 1989

BackgroundConcern about quinacrine lingers because of its carcinogenic effects in rats. We describe results of long-term follow-up of women who underwent quinacrine pellet sterilization in Chile between 1977 and 1989 (N=1492). MethodsWe interviewed the women or relatives in five rounds of data collection between 1991–1993 and 2006–2007, and reviewed hospital records. Median follow-up was 18.5 years; total person-time was 23,894 woman-years. This analysis focuses on pelvic and abdominal surgeries and conditions. We used survival analysis to estimate the 15-year cumulative probability of hysterectomy, other pelvic surgical procedures and relevant adverse events. ResultsUterine fibroids were by far the most common gynecologic condition, reported by 11% of the cohort. Surgical procedures were recorded for 15% of the cohort; hysterectomy was the most frequent procedure (10%), followed by salpingectomy (2%). The 15-year probability of any pelvic or abdominal procedure was 14.7 per 100 women (95% confidence interval 12.4–16.9). The probability of hysterectomy was 9.3 per 100 women (95% confidence interval 7.4–11.1). Number of quinacrine insertions had little impact on the probabilities. ConclusionDuring long-term follow-up of women who received quinacrine pellets for nonsurgical sterilization, the incidence of noncancer adverse outcomes was not unusually high, and no alarming patterns emerged.

Quinacrine synergizes with 5-fluorouracil and other therapies in colorectal cancer

Although treatments have improved patient prognosis in surgically resectable colorectal cancer, new effective drugs with improved safety profiles are needed to improve the currently poor outcomes of patients with recurrent or metastatic colorectal cancer. Quinacrine, a small molecule anti-malarial agent that has activity in giardiasis, lupus, prion disease, and used as a means of non-surgical sterilization, has shown cytotoxic activity across a broad range of cancers. Here, we evaluate the potential of adding quinacrine to anticancer chemotherapeutics and targeted agents as a potential novel combinatorial therapy for advanced colon cancer. We show that quinacrine synergizes with 5-fluorouracil and significantly enhances the cytotoxicity of sorafenib in a panel of 10 human colorectal cancer cell lines, including those with KRAS mutations protein gel blot analysis confirmed that quinacrine’s anticancer activity partially arises from its ability to stabilize p53 and lower anti-apoptotic protein levels. In a series of in vivo studies, quinacrine monotherapy lowered the tumor load of nu/nu mice bearing human colorectal cancer xenografts. In combination, quinacrine and 5-Fluorouracil significantly delayed tumor growth of a variety of different xenografts, as compared to each agent administered alone. Our results suggest that the administration of quinacrine in combination with chemotherapeutic agents and targeted agents should be further explored in patients with recurrent, locally advanced, or metastatic colorectal cancer.

Abstract 674: Novel combinatorial quinacrine cancer therapies for advanced colon cancer

Abstract BACKGROUND: Although treatments have improved patient prognosis in early stages of colorectal cancer, new effective drugs with improved safety profiles are needed for improving the treatment of patients with advanced colon cancer. Quinacrine, a small molecule anti-malarial agent that has activity in giardiasis, lupus, prion disease, and used as a means of non-surgical sterilization, has shown cytotoxic activity across a broad range of cancers. The well characterized safety profile of quinacrine and its anticancer activity hold promise in novel combinatorial cancer therapies. OBJECTIVES: To evaluate the potential of adding quinacrine to anticancer chemotherapeutics and targeted agents as a potential novel combinatorial therapy for advanced colon cancer and to detail the mechanism of action of quinacrine when combined with cancer chemotherapy and targeted agents. METHODS: In vitro dose-response curves and isobolograms were constructed for single agent and dual agent therapies using quinacrine, 5-fluorouracil, gemcitabine, and sorafenib using the following colon cancer cell lines: HT-29, HT-29-luc, HCT-15, HCT-116, HCT-116 p53−/−, HCT-116 bax−/−, RKO, DLD-1, SW-480, and SW-620. Western blot analysis and flow cytometry were used to investigate potential mechanisms of action and to examine cell death. In vivo experiments were carried out to investigate toxicity and efficacy of combinatorial quinacrine chemotherapy in an athymic nu/nu mouse tumor xenograft model with human HT-29-luc cells. RESULTS: Single-agent quinacrine demonstrates potent anticancer activity with an average IC50 of 5.79 ± 0.83 μM across all ten colon cancer cell lines screened. In combination, quinacrine enhanced the anticancer activity of 5-fluorouracil and gemcitabine while significantly synergizing with sorafenib. Western blot analysis revealed that quinacrine's anticancer activity partially arises from its ability to stabilize p53, elevate death receptor levels, and lower anti-apoptotic protein levels. Quinacrine, when combined with sorafenib, dramatically lowers levels of the anti-apoptotic protein MCL-1. In vivo studies have shown that quinacrine monotherapy at a daily dose of 150 mg/kg significantly lowers the tumor load of nu/nu mice. CONCLUSIONS: Quinacrine is cytotoxic to a broad range of colon cancer cells lines and enhances the anticancer activity of chemotherapies such as 5-fluorouracil, gemcitabine, and sorafenib. The administration of quinacrine in combination with chemotherapy agents and targeted agents in patients with advanced colon cancer should be further explored in the clinic. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 674. doi:10.1158/1538-7445.AM2011-674

Clinical Evaluation of Non-surgical Sterilization of Male Cats with Single Intra-testicular Injection of Calcium Chloride

BackgroundCalcium chloride solution is an established injectable sterilant in dogs and other mammals. With cat populations a continuing problem, we sought to explore its first use in cats. Six cats per group were injected with 5%, 10% or 20% calcium chloride dihydrate in saline solution with lignocaine hydrochloride, a local anaesthetic.ResultsAt the 60th day post-injection, cat testes were collected and showed complete testicular necrosis and replacement by fibrous tissue; very low sperm counts; and reduction of serum testosterone by at least 70% in 20% dose. Androgenic enzyme activities and their expressions were also reduced in all the treated groups along with intra-testicular testosterone concentration was also low. Increased testicular lipid peroxidation, with reduced antioxidants and mitochondrial membrane potential, were evident following calcium chloride treatments. However, there were no apparent changes in serum concentrations of cortisol, fasting blood sugar level, blood urea nitrogen, packed cell volume, or total serum protein following calcium chloride injection, suggesting that this method of sterilization is not associated with any general stress response.ConclusionCalcium chloride solution demonstrates potential for androgenesis-eliminating nonsurgical sterilization of male cats in addition to its proven efficacy in dogs and other mammals.

Exploration of a new procedure for sterilization by intrauterine instillation of a methylcellulose gel

Background Our goal was to evaluate a new gel and procedure for non-surgical sterilization. Study Design We injected a methylcellulose-based gel containing a radiographic contrast agent into the uteri of 15 women, varying the gel viscosity, volume injected, injection speed and continuity and duration of cervical blockage. We monitored gel distribution with fluoroscopy and spot imaging, and subjects' condition by interview and examination. Results The gel and procedure were safe and acceptable. The low-viscosity gel reached at least the ampullae of all tubes, but retention in the isthmuses was shorter than 5 min in more than 25% of tubes studied. The high-viscosity gel did not consistently pass into and through the fallopian tubes. Conclusions This study did not identify a gel and insertion procedure that would reliably provide exposure of both fallopian tubes to a sclerosing agent for more than a brief period of time.

A Cure for Euthanasia?

A nonsurgical sterilant could reduce the global population of homeless dogs and cats, but there hasn't been money to develop one—until now.

A lifetime cancer bioassay of quinacrine administered into the uterine horns of female rats

This study investigated if quinacrine can induce a tumorigenic response in rats when administered in a manner similar to the intended human use for female non-surgical sterilization. Young sexually mature female rats received two doses of quinacrine (or 1% methylcellulose control) into each uterine horn approximately 21 days apart, and were observed for 23 months after the second dose administration. Dose levels were 0/0, 0/0, 10/10, 70/70, and 70/250–350 mg/kg (first dose/second dose), which represent local doses in the uterus at approximate multiples of 1×, 8× and 40× the human dose (mg quinacrine/g uterine weight) used for female non-surgical sterilization. Rats were observed for viability, clinical signs of toxicity, and changes in body weight and food consumption. At necropsy, selected organs were weighed, macroscopic observations were recorded, and tissues were collected, fixed, processed, and examined for microscopic pathologic findings. Acute quinacrine toxicity was evident during the dosing period but did not affect long-term survival. Non-neoplastic findings were more common in treated animals than controls, providing evidence of the appropriateness of the bioassay. The incidence of uncommon tumors of the reproductive tract was similar to controls at doses of 10/10 mg/kg but increased with dose level and was significantly greater than controls at ⩾70/70 mg/kg. We conclude that two doses of quinacrine administered approximately 21 days apart into the uterus of young sexually mature rats at a local dose approximately 8 times the human dose used for non-surgical female sterilization increased the lifetime risk of tumor development in the reproductive tract.

Contraceptive effectiveness of two insertions of quinacrine: results from 10-year follow-up in Vietnam

BackgroundThis study was conducted to evaluate the long-term effectiveness of two insertions of quinacrine pellets for nonsurgical sterilization among women in northern Vietnam. Study DesignObservational cohort study of 1335 women who received two quinacrine insertions between 1989 and 1993. ResultsAbout 90% of the study population participated in the last round of interviews. Cumulative follow-up time for this cohort was 14,294 person-years. The 1-, 5- and 10-year cumulative pregnancy probabilities for quinacrine were 3.3% (95% CI, 2.4–4.3), 10.0% (95% CI, 8.4–11.6) and 12.1% (95% CI, 10.4–13.9), respectively. Pregnancy estimates with quinacrine in this cohort were higher than that reported from US-based research on surgical tubal sterilization and higher than results of quinacrine sterilization in Chile. Quinacrine effectiveness was better among older women. ConclusionThe effectiveness of quinacrine in Vietnam was lower than other forms of sterilization. Factors such as inconsistent training and use of various insertion techniques may have contributed to the relatively high failure rate.

Safety of quinacrine contraceptive pellets: results from 10-year follow-up in Vietnam

BackgroundThis study was conducted to evaluate long-term safety of quinacrine pellets for nonsurgical sterilization among women in Vietnam. Study DesignObservational cohort study of 2735 women who had quinacrine insertions between 1989 and 1993 compared to 1623 women who received an intrauterine device (IUD). ResultsCumulative follow-up times for the quinacrine and IUD cohorts were 28,697 and 17,382 person-years, respectively, and losses to follow-up were 6% and 7%, respectively. Quinacrine users had a higher incidence of ectopic pregnancy compared to IUD users (risk ratio, 2.2; 95% confidence interval, 1.06–4.54); the risks of cancer, hysterectomy, pelvic/gynecologic surgery and death were similar in the two groups. Two quinacrine insertions appeared to lower the risk of ectopic pregnancy to that of surgical tubal occlusion. ConclusionsUse of quinacrine in this cohort appeared to have minimal health risks. Other research, including preclinical studies, needs to be considered in an overall evaluation of whether the combination of safety and efficacy provide a basis for quinacrine's approval by appropriate regulatory agencies.

FHI's decision to halt development of quinacrine: why and how

Quinacrine has been studied as a method of nonsurgical female sterilization for over 25 years but does not have FDA approval for this indication. It has been the subject of controversy, and FHI's work on quinacrine is closely followed by researchers and stakeholders. For 10 years, FHI has been working toward development of an FDA-approved quinacrine product for nonsurgical sterilization.

Non-surgical methods of contraception and sterilization

The Humane Society of the United States estimates that each year between 8 and 10 million dogs and cats enter shelters and 4–5 million of these animals are euthanized due to lack of homes. Many veterinarians within the United States recommend surgical sterilization for population control in dogs and cats. However, there are non-surgical methods to control reproduction. Pharmacologic methods of contraception and sterilization can be safe, reliable and reversible. Hormonal treatments using progestins, androgens, or gonadotropin releasing hormone (GnRH) analogs act to either directly block reproductive hormone receptor-mediated events, or indirectly block conception via negative feedback mechanisms. Immunocontraception, via vaccination against GnRH, the luteinizing hormone receptor or zona pellucida proteins, is also possible. Intratesticular or intraepididymal injections provide a method for non-surgical sterilization of the male dog and cat. Additional methods have been employed for mechanical disruption of fertility including intravaginal and intrauterine devices and ultrasound testicular ablation. Alternative approaches to surgical sterilization will be reviewed.

Effects of a GnRH cytotoxin on reproductive function in peripubertal male dogs

Methods for long-term or permanent disruption of reproductive function via nonsurgical techniques are needed for a variety of species, including companion animals. In a previous study, we demonstrated the ability of a cytotoxin (pokeweed antiviral protein—PAP) conjugated to d-Lys6-GnRH, to disrupt reproductive function in adult male dogs. The objective of the present study was to examine the ability of a d-Lys6-GnRH-PAP conjugate to disrupt reproductive function in peripubertal male dogs. Peripubertal male dogs (n=15; approximately 16–32 weeks old) were treated with d-Lys6-GnRH-PAP as follows: dogs (n=7; Group I) received GnRH-PAP (0.1mg/kg SQ) with a second treatment (0.25mg/kg) 20 weeks later. An additional group (n=3; Group II) of peripubertal dogs was treated with GnRH-PAP (0.25mg/kg) twice (20 weeks apart). Control dogs (n=5) received d-Lys6-GnRH analog (0.0045mg/kg SQ) without PAP. Efficacy was assessed by monitoring testis size, serum concentrations of testosterone and LH, as well as LH release subsequent to a GnRH (5μg/kg) stimulus. Dogs in Group I (n=5) that did not respond to the initial two treatments were given a third GnRH-PAP injection (0.25mg/kg), 12 months after the initial treatment. The initial GnRH-PAP treatment in peripubertal male dogs did not affect testis growth, LH release or serum testosterone concentrations; however, administration of a higher dose of GnRH-PAP after puberty resulted in a marked and rapid decline in testis size, serum testosterone concentrations and LH responsiveness to GnRH stimulation in 9 of 10 dogs. Suppression of reproductive function was maintained in treated dogs for 18–50 weeks; four dogs had suppression of reproductive activity through the end of the study. In conclusion, GnRH-PAP given after puberty markedly suppressed reproductive activity. Due to variability in the response and duration of suppression after treatment with GnRH-PAP, more research is required to determine its efficacy for nonsurgical sterilization of the male dog.

Evaluation of single intratesticular injection of calcium chloride for nonsurgical sterilization in adult albino rats

Objective To investigate a method of chemical sterilization and its efficacy in adult albino rats. Method Evaluation was conducted 3 weeks after a single bilateral intratesticular injection of calcium chloride (CaCl 2) at the dose of 5, 10, 15 or 20 mg per testis per 100 g body weight. Results The significant graded diminution in relative sex organ weights, testicular androgenic enzymes like Δ 5,3β-hydroxysteroid dehydrogenase (Δ 5,3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities, testicular content of reduced glutathione (GSH), plasma and intratesticular concentrations of testosterone, epididymal sperm count as well as significant elevation in plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testicular content of malondialdehyde (MDA) were noted in all the treated groups with respect to vehicle control. There was no chronic general stress in experimental animals as indicated by insignificant changes in plasma concentrations of corticosterone, prolactin, total protein, blood urea nitrogen and fasting blood sugar level. Dose-dependent responses on testicular histopathology were recorded by noting multinucleated giant cells in seminiferous tubules, derangement of tubular architecture along with infiltration of leucocytes and appearance of fibrous tissue throughout the testicular sections. The fertility efficacy of the 10, 15 or 20 mg CaCl 2-treated males was nil, proven after mating with fertile, virgin healthy females, as there were no implantation sites in each uterine horns noted by laparotomy. Conclusion Intratesticular CaCl 2 injection at a specific dose might serve as a way of sterilization and may be considered as an alternative to surgical castration in male animals.

Evaluation of single intratesticular injection of calcium chloride for nonsurgical sterilization of male Black Bengal goats ( Capra hircus): a dose-dependent study

This study describes the induction of chemosterilization in three groups each of six adult male Black Bengal goats at 30 days after a single bilateral intratesticular injection of a calcium chloride (CaCl 2, 2H 2O) solution at the doses of 10, 20 or 40 mg/kg body weight/testis, always in a 2 ml volume of normal saline. Another one group of animals received only 2 ml of normal saline per testis as a control. The induction of chemosterilization was measured using relative testicular weight as well as histomorphological parameters including seminiferous tubular architecture and germ cell association in seminiferous tubules along with morphology of the interstitial space. Biochemical markers included activities of testicular Δ 5, 3β-hydroxysteroid dehydrogenase (Δ 5, 3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), catalase, glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) as well as monitoring the level of testicular thiobarbituric acid reactive substances (TBARS), conjugated dienes and reduced glutathione (GSH) content along with plasma concentrations of testosterone, LH and FSH. Histomorphological measures of testes showed total necrosis of testicular tissue at 30 days after an injection of either 20 or 40 mg CaCl 2 along with fibrosis in seminiferous tubules and interstitial spaces. Infiltration of leucocytes was observed with the 40 mg dose. Disintegration of germ cell arrangement in seminiferous tubules and washing out of germ cells from the tubules were noted with the 10 mg dose. Relative organ weights, plasma concentrations of testosterone, testicular activities of Δ 5, 3β-HSD, 17β-HSD, catalase, GPx, GST, and SOD and testicular contents of GSH all were declined. Increases occurred in testicular TBARS, conjugated dienes and plasma concentrations of LH and FSH with each of the treatments by comparison with the control group. Plasma concentrations of cortisol and fasting blood sugar level as well as packed cell volume (PCV) and total plasma protein were recorded to monitor the changes of chronic stress in the experimental animals. Changes in these parameters were not significant. An intratesticular injection of calcium chloride at specified doses could be a suitable method of sterilization in preference to surgical castration of goats.

Nonsurgical Sterilization Using the ESSURE Device in the Fallopian Tubes: Results in Rabbits

Abstract A potential method of nonsurgical tubal sterilization was tested in rabbits to gain Food and Drug Administration (FDA) approval for testing in women. The study design consisted of 37 rabbits, with 74 reproductive tracts that received either no intervention (22 tracts), catheterization only (23 tracts), or attempt at placement of a metal device in the fallopian tube (29 tracts) using a combination of hysteroscopic and fluoroscopic catheterization. Animals were bred and then euthanized, and contraceptive effect documented. No embryos were found in the 14 uteri associated with fallopian tubes containing the ESSURE device (0 conceptions; 100% contraception). In comparison, embryos were found in 36 of the 45 uteri in which a device was not placed (80% conceptions; 20% contraception). Difficulty placing or expulsion of the device occurred in 11 (39%) of the rabbit reproductive tracts, which are more difficult to catheterize than those of women. ESSURE prevented conception 100% of the time in the rabbit when the metal device remained in the fallopian tube. Based on this data, the FDA approved clinical trials using this device, and recently approved placement in women. It is therefore the first alternative to tubal ligation for women seeking permanent birth control in the United States.