Endocrine, prostatic vascular, and proapoptotic changes in dogs with benign prostatic hyperplasia treated medically or surgically.

Benign prostatic hyperplasia (BPH) is a disorder related to hormone imbalance, local angiogenesis, and prostate growth, which can be treated surgically (orchiectomy) or medically (most commonly with finasteride). However, finasteride therapy is not completely established in dogs regarding local action and posology. This study aimed to evaluate the effect of different doses of finasteride and orchiectomy on hormonal profile, prostate apoptosis, blood flow, and biometry in dogs with BPH. Dogs were assigned to the following groups: untreated, 0.1 mg, 0.2 mg, and 0.5 mg/kg/d of finasteride and orchiectomy. All dogs were assessed monthly: day 0 (before treatment), day 30, and day 60 and subjected to prostate B-mode and Doppler ultrasonography and hormonal analysis (testosterone and dihydrotestosterone). After 60 d, prostatic biopsy was performed for histology and immunohistochemical evaluation for apoptosis (caspase-3). On day 60, percentage reduction of prostatic volume was greater in orchiectomized dogs than that in finasteride groups, which, conversely, was greater than untreated dogs. On day 60, 0.2-mg finasteride, 0.5-mg finasteride, and orchiectomy groups had higher prostatic blood flow than 0.1-mg finasteride and untreated groups. In addition, both 0.5-mg finasteride and orchiectomy groups had an increase in prostate artery resistance. Orchiectomy significantly decreased androgen concentrations at 30 d onward, differing from the remaining groups. The orchiectomy group had lower caspase-3 immunostaining, however, not different from untreated and 0.5-mg finasteride. In conclusion, 0.5 mg/kg finasteride promoted more effective prostate apoptosis and hemodynamic effects among medical treatments, whereas orchiectomy caused prostate atrophy and sharp endocrine changes in dogs with BPH.

Perinatal cortisol and blood glucose concentrations in bitches and neonatal puppies: effects of mode of whelping.

The decision on how and when to assist whelping is crucial for the survival rate of puppies and health status of the dam. However, medical or surgical therapy in dystocia can impact both maternal and neonatal stress and glucose response differently. This study aims to compare perinatal cortisol and glucose among different modes of delivery in bitches and neonates. We analyzed 50 puppies derived from 27 healthy bitches. According to the condition at birth, bitches and their puppies were allocated into either a Eutocia Group (vaginal birth with no whelping assistance), Fetal Dystocia Group (whelping assistance with fetal manipulation), Maternal Dystocia Group (whelping assistance because of partial uterine inertia corrected by oxytocin administration), or Cesarean Section Group (fetal or maternal dystocia bitches subjected to C-section). Maternal blood cortisol and glucose concentrations were analyzed during the perinatal period (prepartum, intrapartum, postpartum, and 1 h after postpartum). Neonatal blood samples were collected within 5 min and 1 h after birth for assessment of cortisol and glucose. Maternal dystocia bitches had higher cortisol concentrations at postpartum than the Fetal Dystocia Group. At 1 h postpartum, the Cesarean Section Group had higher cortisol concentrations compared with fetal dystocia bitches. The Eutocia Group presented increased cortisol concentrations at intrapartum and postpartum, whereas fetal dystocia bitches had higher intrapartum cortisol concentrations than at 1 h postpartum. The Maternal Dystocia Group presented higher postpartum cortisol concentrations than at prepartum and 1 h postpartum. Maternal glucose had a progressive increase throughout peripartum and was higher during postpartum and at 1 h postpartum. C-section bitches had the highest blood glucose concentration. Neonatal cortisol concentrations at birth were higher than 1 h after birth. Fetal dystocia puppies had higher cortisol concentrations, whereas caesarian section puppies had lower cortisol levels. Fetal dystocia and C-section puppies had higher glucose concentrations than the Eutocia Group. In conclusion, maternal dystocia leads to high cortisol concentrations in bitches immediately postpartum, whereas only fetal dystocia causes increased neonatal cortisol concentrations. Moreover, fetal dystocia and C-section are hyperglycemic obstetrical conditions for neonatal puppies; on the other hand, only C-section causes hyperglycemia in bitches.

Morphometric and functional pulmonary changes of premature neonatal puppies after antenatal corticoid therapy.

Among prematurity complications, the most important disorder is structural immaturity and inadequate production of pulmonary surfactant. Betamethasone is the drug of choice to artificially improve pulmonary capacity, thus we aimed to verify the effect of prenatal maternal treatment on lung development of premature puppies. Pregnant bitches were allocated in Term Group (n = 7), Preterm-Treated Group (interrupted pregnancies with maternal administration of betamethasone; n = 7), Preterm-Control Group (untreated interrupted pregnancies; n = 7), Extremely-Preterm Group (interrupted pregnancies at 55d; n = 6). Puppies were subjected to chest radiographic at birth, morphometric description of pulmonary structures and immunohistochemical analysis of surfactant protein B, proliferating cell nuclear antigen and cytokeratin were performed. In Preterm-Treated Group it was possible to more clearly identify cardiac silhouette and lung parenchyma by X-Ray. Saccular formation was higher in Preterm Groups, while Term Group had higher subsaccular development. Lung septation was higher in Treated and Term Groups. Term Group had higher number of cells marked for SP-B, whereas higher proliferation was observed in Extreme-Preterm and Preterm-Control Groups. Preterm Treated and Term Groups had higher tissue differentiation. In conclusion, antenatal maternal corticotherapy in dogs acted by increasing lung morphology and development of areas of gas exchange, regulate metabolism of pulmonary fluids rather than stimulate surfactant production.

Effects of benign prostatic hyperplasia and finasteride therapy on prostatic blood flow in dogs.

Benign prostatic hyperplasia (BPH) is characterized by an enlargement of the prostate accompanied by an increase in prostatic blood perfusion and vascularization. The most indicated treatment is to perform orchiectomy, however, medical treatment with finasteride can be an option for breeding dogs or elderly animals with a critical health status. In dogs, the influence of medical treatment on prostatic hemodynamics is still unknown. Therefore, this study aimed to evaluate the effects of benign prostatic hyperplasia and finasteride therapy on hemodynamic and vascular features of the canine prostate. For this purpose, twenty dogs of different breeds, body weights (10-30 kg) and ages (5-13 years) were used, assigned for: Healthy-non treated group (n = 5), BPH-non treated group (n = 5), Healthy-finasteride treated group (n = 5) and BPH-finasteride treated group (n = 5). Dogs that presented hematospermia and at least one general clinical sign (tenesmus, hematuria or dysuria) were presumptively diagnosed with BPH. Dogs were evaluated ultrasonographycally by B-mode and Doppler of the prostatic artery in a monthly interval (day 0, 30 and 60) in order to measure prostate volume (PV), expected prostate volume (EPV), prostate vascularization score (scored as minimum, intermediary and maximum) and prostatic artery blood flow parameters with the use of spectral and color Doppler ultrasound. It was possible to observe a decrease in prostate vascularization score between Day 0 (intermediary degree) and 60 (minimum degree) in finasteride treated dogs. Moreover, non-treated dogs had higher score of vascularization at Day 60 compared to animals treated with finasteride, regardless of BPH diagnosis. Healthy-non treated animals presented higher peak systolic:diastolic velocity (S/D) than BPH-non treated dogs. Furthermore, BPH-non treated dogs had lower S/D than BPH-finasteride treated dogs. In 30 and 60 days, no difference on PV was observed between BPH-finasteride treated group and Healthy-non treated group. At day 60, no difference between PV and EPV was observed for the BPH-finasteride treated group. In conclusion, finasteride treatment reduces simultaneously the volume, local vascularization and blood flow of the prostate, thus, being considered an effective and additional choice of therapy for BPH. Moreover, the course of therapy in dogs can be followed by analyzing changes in prostatic artery.

The use of reduced glutathione (GSH) as antioxidant for cryopreserved sperm in dogs / O uso da glutationa reduzida (GSH) como antioxidante na criopreservação seminal em cães

The aim of this study was to evaluate the effect of supplementation with different concentrations of reduced glutathione GSH (0; 5; 7.5; 10mM) in the extender for cryopreservation in dogs with evaluations performed after glycerolization (chilled) and thawing (thawed). For this purpose, we used 8 dogs and two semen collections were performed in a weekly interval, totaling 16 semen samples. The sperm were analyzed by automatic sperm motility (CASA) and flow cytometry analysis of mitochondrial potential (JC1 dye) and membrane/acrosome integrity (FITC-PI dyes). We evaluated subjectively the membrane and acrosome integrity, mitochondrial activity and DNA integrity. Seminal plasma was evaluated for lipid peroxidation (TBARS concentration). Chilled and thawed samples supplemented with 7.5 and 10mM of GSH had lower percentage of sperm with high (DAB - Class I) and medium (DAB - Class II) mitochondrial activity. And 10mM of GSH had higher percentage of low mitochondrial activity (DAB - Class III). Moreover, thawed samples of 10mM of GSH had high DNA fragmentation rates. Probably by a reductive stress effect on mitochondria which lead to an increase in reactive oxygen species, and a mitochondrial malfunction.(AU)

O objetivo deste estudo foi avaliar o efeito da suplementação com diferentes concentrações de glutationa reduzida (GSH - 0; 5; 7,5; 10mM) para criopreservação em cães com avaliações realizadas após glicerolização (refrigeração) e descongelação. Para tal, foram utilizados oito cães e foram realizadas duas coletas de sêmen em intervalo semanal, totalizando 16 amostras de sêmen. Foram avaliadas a motilidade espermática computadorizada (CASA) e a análise de citometria de fluxo do potencial mitocondrial (sonda JC-1) e integridade da membrana/acrossomal (sonda FITC-PI). Subjetivamente foi avaliada a integridade da membrana plasmática e do acrossomal, atividade mitocondrial e integridade do DNA. O plasma seminal foi avaliado quanto à peroxidação lipídica (concentração de TBARS). As amostras refrigeradas e descongeladas suplementadas com 7,5 e 10mM de GSH apresentaram menor porcentagem de espermatozoides com alta atividade mitocondrial (DAB - Classe I) e média (DAB - Classe II). Na concentração de 10mM de GSH, apresentaram maior porcentagem de baixa atividade mitocondrial (DAB - Classe III). Além disso, amostras descongeladas de 10mM de GSH apresentaram taxas de fragmentação de DNA elevadas, provavelmente por efeito de estresse redutivo sobre as mitocôndrias que elevam as espécies reativas de oxigênio e disfunção mitocondrial.(AU)

Influence of prenatal maternal corticosteroid therapy on clinical and metabolic features and pulmonary function of preterm newborn puppies.

Although the effects of antenatal corticosteroid therapy in clinical improvement and pulmonary maturation in preterm have been described, little is known on premature newborn puppies. This study aimed to evaluate the effect of maternal administration of a single dose of prenatal betamethasone on lung function of preterm newborn puppies in the first hours of life, especially from the clinical point of view and acid-base balance. A prospective study was conducted involving 21 puppies allocated into three experimental groups: Term Group (63 days post-ovulation), Preterm-Treated Group (57 days post-ovulation and maternal administration of a single dose of 0.5 mg/kg of betamethasone) and Preterm-Control Group (57 days post-ovulation). Puppies were analyzed clinically through the Apgar score, heart rate, respiratory rate and neurological tests (muscular tone and irritability reflex) and for oximetry and blood acid-base balance in distinct experimental moments. Premature puppies had marked degree of prematurity, reversed by maternal administration of betamethasone. Prenatal corticosteroid therapy promoted better pulmonary and metabolic condition, with more efficient compensatory response to acid-base imbalance and better pulmonary gas exchange capacity. Therefore, prenatal treatment with betamethasone can be adopted as clinical lung maturation protocol for pregnancies at risk in order to prevent low vitality and increase neonatal survival.

Cytoplasmic droplet acting as a mitochondrial modulator during sperm maturation in dogs.

Motility acquisition during sperm maturation and passage through the epididymis is closely related to mitochondrial function and appears to occur in parallel with cytoplasmic droplet (CD) migration. However, such mechanism remains unclear in dogs. Thus, the aim of this study was to characterize the influence of sperm CD in the mitochondrial functionality during epididymal sperm maturation in dogs. Twenty-one adult dogs were submitted to elective bilateral orchiectomy. Testicles were stored for 18-24h at 5°C and epididymal sperm samples were then collected from different segments of the epididymis (caput, corpus and cauda). Samples were evaluated for computer-assisted motility analysis (CASA), presence of CD (eosin/nigrosin stain), ultrastructural CD analysis and sperm mitochondrial activity (3,3' diaminobenzidine technique) and membrane potential (JC-1 probe). Samples collected from the corpus epididymis showed higher motility and mitochondrial activity in comparison to the caput sperm. Moreover, corpus sperm had lower percentage of proximal droplets compared to caput samples, while mitochondrial membrane potential remained unchanged. Cauda samples showed higher motility, mitochondrial activity and potential, however, lower presence of sperm droplets (proximal and distal). In conclusion, the CD is essential for epididymal sperm maturation in dogs, showing important functions along the transit in the epididymis. In the corpus segment, the migration of the CD along the sperm midpiece provides a high mitochondrial activity and the onset of sperm motility. On the other hand, sperm from cauda epididymis lack CD but suffered lipid membrane changes which allow a maximum mitochondrial membrane potential and motility.

Effect of mitochondrial uncoupling and glycolysis inhibition on ram sperm functionality.

Studies have demonstrated the importance of mitochondria to sperm functionality, as the main source of ATP for cellular homoeostasis and motility. However, the role of mitochondria on sperm metabolism is still controversial. Studies indicate that, for some species, glycolysis may be the main mechanism for sperm energy production. For ram sperm, such pathway is not clear. Thus, we evaluated ram sperm in response to mitochondrial uncoupling and glycolysis inhibition aiming to assess the importance of each pathway for sperm functionality. Statistical analysis was performed by the SAS System for Windows, using the General Linear Model Procedure. Data were tested for residue normality and variance homogeneity. A p < .05 was considered significant. Groups treated with the mitochondrial uncoupler Carbonyl cyanide 3 chlorophenylhydrazone (CCCP) showed a decrease in the percentage of cells with low mitochondrial activity and high mitochondrial membrane potential. We also observed that the highest CCCP concentration promotes a decrease in sperm susceptibility to lipid peroxidation. Regardless the lack of effect of CCCP on total motility, this substance induced significant alterations on sperm kinetics. Besides the interference of CCCP on spermatic movement patterns, it was also possible to observe such an effect in samples treated with the inhibitor of glycolysis (2-deoxy-d-glucose, DOG). Furthermore, treatment with DOG also led to a dose-dependent increase in sperm susceptibility to lipid peroxidation. Based on our results, we suggest that the glycolysis appears to be as important as oxidative phosphorylation for ovine sperm kinetics as this mechanism is capable of maintaining full motility when most of the cells have a low mitochondrial membrane potential. Furthermore, we found that changes in the glycolytic pathway trough glycolysis inhibition are likely involved in mitochondrial dysfunction and sperm oxidative unbalance.

Uterine haemodynamic, vascularization and blood pressure changes along the oestrous cycle in bitches.

Characterization of the bitch's reproductive physiology is of utmost importance for the development of new reproductive techniques and the diagnosis of reproductive diseases. In this respect, uterine B-mode ultrasonography has been employed in several studies; however, the focus on haemodynamic changes along the oestrous cycle is yet to be described. Thus, the aim of this study was to characterize haemodynamic changes (uterine vascularization, systemic arterial blood pressure and heart rate) throughout the oestrous cycle in bitches. For this purpose, ten Golden Retriever bitches were evaluated during an entire oestrous cycle, twice during each stage of the cycle. Uterine artery blood flow, velocity wave forms, haemodynamic parameters and vascularization were analysed by Doppler ultrasonography. Furthermore, uterine diameter, arterial blood pressure and heart rate were measured. Uterine artery pulsatility index at early prooestrus was significantly lower in comparison with early oestrus, mid- and late anoestrus. Uterine artery resistance index was higher at early oestrus when compared to late oestrus and uterine diameter was significantly higher during late prooestrus. Furthermore, mean arterial blood pressure was lower and heart rate was higher during late prooestrus in comparison with the other oestrous cycle stages. In conclusion, haemodynamic changes in the uterine artery, uterine diameter, systemic blood pressure and heart rate occur during the canine oestrous cycle. Specifically, there is an increase in uterine artery perfusion, uterine diameter and mean arterial blood pressure during prooestrus, while uterine blood flow diminishes during oestrus and anoestrus.

Lipid composition of the canine sperm plasma membrane as markers of sperm motility.

The fatty acid composition of the sperm membrane is an important factor involved in the overall sperm quality, including motility. However, in the canine species, the exact composition of the plasma membrane is still unknown. Therefore, the purpose of this study was to evaluate the plasma membrane lipid composition of motile sperm cells and to compare it with asthenospermic samples, as an attempt to determine possible involvements of membrane lipids in dog sperm cell motility. The sperm-rich fraction of ten mature dogs was collected, and samples were subjected to density gradient centrifugation by Percoll® , in order to separate motile and asthenospermic samples. Processed semen samples were evaluated for sperm motility, plasma and acrosome membrane integrity, mitochondrial activity and susceptibility to oxidative stress. Lipid plasma membrane composition was identified by mass spectrometry (MALDI-MS). The motile sperm samples presented the following phospholipids in a high frequency in the plasma membrane: phosphatidylcholine 38:4 (composed of stearic and arachidonic fatty acids), phosphatidylcholine 36:1 (stearic and oleic fatty acids), phosphatidylethanolamine 34:4 (myristic and arachidonic fatty acids), glycerophosphatidic acid 36:4 (palmitic and arachidonic fatty acids), phosphatidylcholine 40:4 plasmanyl and phosphatidylcholine 40:5 plasmenyl. Furthermore, no lipid markers were found in the asthenospermic samples. Results also indicate that differences on plasma membrane composition between motile and asthenospermic samples are crucial factors for determining sperm motility, sperm functionality and susceptibility to oxidative stress. In conclusion, plasma membrane lipid composition varies considerable between motile and asthenospermic samples. Therefore, lipid markers of sperm motility can be considered, such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylcholine plasmanyl, phosphatidylcholine plasmenyl and phosphatidic acid.

The influence of benign prostatic hyperplasia on sperm morphological features and sperm DNA integrity in dogs.

Benign prostatic hyperplasia (BPH) has a high incidence in older intact dogs. Due to the increased prostatic oxidative stress and hormonal imbalance of BPH, sperm damage can arise, such as sperm morphological alterations and DNA fragmentation. This study aimed to compare the reproductive potential of healthy dogs and those affected by benign prostatic hyperplasia. Ten dogs were assigned to two experimental groups: dogs without BPH (control; n = 5) and dogs diagnosed with BPH (n = 5), based on clinical signs and ultrasonographic findings. Three semen collections were performed from each dog within one month and analysed using computer-assisted sperm analysis (CASA) and functional tests. Control group showed higher percentage of sperm DNA integrity (95 ± 1.8%) compared to the BPH group (79.2 ± 6.4%). On the other hand, the percentage of minor sperm defects, amplitude of lateral sperm head displacement of the spermatozoa and medium sperm mitochondrial activity were higher in the BPH group. In conclusion, BPH decreases sperm DNA integrity, increases mitochondrial activity, as well as modifies sperm movement pattern. Therefore, a careful sperm analysis of aged dogs with BPH is required before a reproductive programme can be established for such patients.

The influence of canine brucellosis on morphofunctional features of epididymal spermatozoa: case report / Influência da brucelose canina nos aspectos morfofuncionais de espermatozoides epididimários: relato de caso

The present work reports a clinical case of a mongrel dog, with serological diagnosis of brucellosis, from which epididymal sperm analysis was performed. Sperm samples were collected from different segments of the epididymis (tail, corpus, and caput). Sperm samples were evaluated for computer-assisted motility analysis (CASA), spermatic morphology, mitochondrial activity and sperm plasmatic membrane and acrosomal integrity. Changes in sperm movement patterns were found (progressive motility, percentage of rapid sperm, percentage of rapid velocity, average pathway, curvilinear velocity, velocity straight line, amplitude of lateral head displacement, straightness and linearity), increase of total morphological defects (51%) and absence of sperm mitochondrial activity (20%) were verified, especially for cauda epididymides. We highlight that such changes can contribute to clinical diagnosis of Brucellosis in dogs and to the use of epididymal sperm in reproductive biotechnologies.(AU)

Relata-se o caso de um cão mestiço, com diagnóstico sorológico para brucelose canina, a partir do qual foram realizadas análises do sêmen epididimário. As amostras espermáticas foram coletadas dos diferentes segmentos epididimários (cabeça, corpo e cauda). Foram realizadas as avaliações de motilidade computadorizada do sêmen (CASA), morfologia espermática, atividade mitocondrial, integridade das membranas plasmática e acrossomal. Houve alteração no padrão de movimentação espermática (motilidade progressiva, espermatozoides rápidos, velocidade média da trajetória, velocidade curvilínea, velocidade linear progressiva, amplitude de deslocamento lateral da cabeça, retilinearidade e linearidade), aumento do total de defeitos morfológicos (51%) e da ausência de atividade mitocondrial espermática (20%) dos espermatozoides, especialmente da cauda do epidídimo. Ressalta-se que tais achados podem contribuir para o diagnóstico clínico da brucelose canina e para a utilização do sêmen epididimário em biotecnologias da reprodução.(AU)

Effect of reduced glutathione (GSH) in canine sperm cryopreservation: In vitro and in vivo evaluation.

The aim of this study was to compare the in vitro and in vivo efficiency of different concentrations (0, 10 and 20 mM) of reduced glutathione supplemented to the extender for canine semen cryopreservation. Six normospermic dogs were used and each ejaculate was divided in 3 experimental groups, according to GSH concentration (GSH-0, GSH-10 and GSH-20 Groups). After thawing, samples were evaluated by sperm motility by computer-assisted sperm analysis (CASA), flow cytometric evaluation of plasma and acrosome membrane integrity, mitochondrial membrane potential and activity, chromatin susceptibility to acid-induced denaturation, and measurement of spontaneous and induced production of thiobarbituric acid reactive substances (TBARS). In vivo tests were carried out with GSH-0 and GSH-10 groups, for which six bitches were inseminated with semen cryopreserved in extender without GSH or containing 10 mM GSH. Intrauterine insemination was performed by cervical catheterization on the 5th and 6th days after the LH surge, detected by serum progesterone and LH assays. In the CASA evaluation, GSH-20 group had the lowest total and progressive motility and lower percentage of sperm with rapid and slow speed. Groups treated with glutathione showed lower percentage of acrosome damage, but higher percentage of plasma membrane injury. GSH-20 group had higher percentage of sperm with low mitochondrial activity and higher concentration of induced TBARS. Both groups (GSH-0 and GSH-10) had positive pregnancies. In conclusion, 20 mM GSH supplementation to canine cryopreservation extender promoted sperm damage, especially to mitochondrial activity. However, addition of 10 mM GSH resulted in acrosome protection, preserving fertility rate.

Oxidative stress at different stages of two-step semen cryopreservation procedures in dogs.

Sperm cryopreservation generates sperm damage and reduced fertilization capacity as a consequence of reactive oxygen species formation. Identifying the critical points of the process will contribute to the development of strategies for oxidative stress prevention. Therefore, the aim of this experiment was to verify the occurrence of oxidative stress during the two-step cryopreservation process in dogs. Six healthy mature dogs were used and submitted to the two-step sperm cryopreservation protocol. The sperm analysis was done at three time points: after refrigeration, after glycerolization, and after thawing by sperm motility, measurement of spontaneous and induced oxidative stress, sperm mitochondrial activity, plasma membrane integrity, flow cytometric evaluation of plasma and acrosome membrane integrity, mitochondrial membrane potential, and sperm chromatin structure assay. There was an increase in free radical production after glycerolization (87.4 ± 15.5 ng/mL of spontaneous thiobarbituric acid reactive substances (TBARS) after refrigeration and 1226.3 ± 256.0 ng/mL after glycerolization; P < 0.05), in association with loss of sperm mitochondrial activity. However, frozen-thawed samples had lower sperm motility, lower resistance to oxidative stress (448.7 ± 23.6 ng/mL of induced TBARS after glycerolization and 609.4 ± 35.9 ng/mL after thawing; P < 0.05) and increased lipid peroxidation (4815.2 ± 335.4 ng/mL of spontaneous TBARS after thawing; P < 0.05) as well as increased damage to plasma and acrosomal membranes, compared with refrigeration and glycerolization. In conclusion, the production of free radicals by sperm cells begins during glycerolization. However, sperm oxidative damage intensifies after thawing. Despite intracellular ice formation during cryopreservation, the increased production of reactive oxygen species can be the explanation of the decrease in sperm motility, reduced mitochondrial activity, and sperm plasma membrane and acrosomal damage.

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.

Gene expression of estrogen and oxytocin receptors in the uterus of pregnant and parturient bitches

In the canine species, the precise mechanisms of pregnancy maintenance and the initiation of parturition are not completely understood. The expression of genes encoding the receptors for estrogen (ERα mRNA) and oxytocin (OTR mRNA) was studied in the endometrium and myometrium during pregnancy and parturition in dogs. Real-time PCR was performed to quantify the levels of ERα mRNA and OTR mRNA in the uterus of bitches during early (up to 20 days of gestation), mid (20 to 40 days) and late pregnancy (41 to 60 days), and parturition (first stage of labor). All tissues expressed ERα and OTR mRNA, and are thus possibly able to respond to eventual estrogen and oxytocin hormonal stimuli. No statistically significant differences in the expression of ERα mRNA were verified in the endometrium and myometrium throughout pregnancy and parturition, but expression of OTR mRNA increased at both parturition and late pregnancy. We concluded that the increase of endometrial and myometrial OTR mRNA expression in dogs is not an event dependent on estrogenic stimulation. Moreover, the contractility response of the canine uterus to oxytocin begins during pregnancy and maintains myometrial activity. The expression of OTR mRNA in canine uterine tissues varied over time, which supports an interpretation that the sensitivity and response to hormone therapy varies during the course of pregnancy and labor. Further studies are needed to elucidate the factors underlying the synthesis of uterine oxytocin receptors and the possible role of ERβ rather than ERα in the uterine tissues during pregnancy and parturition in dogs.

Gene expression of estrogen and oxytocin receptors in the uterus of pregnant and parturient bitches.

In the canine species, the precise mechanisms of pregnancy maintenance and the initiation of parturition are not completely understood. The expression of genes encoding the receptors for estrogen (ERα mRNA) and oxytocin (OTR mRNA) was studied in the endometrium and myometrium during pregnancy and parturition in dogs. Real-time PCR was performed to quantify the levels of ERα mRNA and OTR mRNA in the uterus of bitches during early (up to 20 days of gestation), mid (20 to 40 days) and late pregnancy (41 to 60 days), and parturition (first stage of labor). All tissues expressed ERα and OTR mRNA, and are thus possibly able to respond to eventual estrogen and oxytocin hormonal stimuli. No statistically significant differences in the expression of ERα mRNA were verified in the endometrium and myometrium throughout pregnancy and parturition, but expression of OTR mRNA increased at both parturition and late pregnancy. We concluded that the increase of endometrial and myometrial OTR mRNA expression in dogs is not an event dependent on estrogenic stimulation. Moreover, the contractility response of the canine uterus to oxytocin begins during pregnancy and maintains myometrial activity. The expression of OTR mRNA in canine uterine tissues varied over time, which supports an interpretation that the sensitivity and response to hormone therapy varies during the course of pregnancy and labor. Further studies are needed to elucidate the factors underlying the synthesis of uterine oxytocin receptors and the possible role of ERß rather than ERα in the uterine tissues during pregnancy and parturition in dogs.

Association between birth conditions and glucose and cortisol profiles of periparturient dairy cows and neonatal calves.

Parturition in cattle is a stressful event for both the dam and the offspring. Stress and pain can alter the energy profile of calves and calving cows, producing a metabolic imbalance at birth. This study aimed to assess the effects of dystocia and oxytocin and calcium infusion on metabolic homeostasis in dairy cows and calves. Thirty Holstein cows and their calves were divided into three groups: an eutocia group (n=10), in which no calving assistance was needed; a dystocia group, which required mild-to-severe obstetric assistance (n=10); and a uterine inertia group, which was treated with oxytocin and calcium (n=10). To assess serum cortisol and blood glucose levels, blood samples were collected during the peripartum period from cows and during the first hour since birth from calves. All groups were hyperglycaemic following parturition. Infusion of oxytocin and calcium resulted in lower maternal glucose concentrations and lower levels of stress than in cows in the dystocia group. Birth condition was significantly associated with blood glucose and cortisol concentrations in calves. Glucose concentration was lower in calves born with oxytocin and calcium infusion than those born with fetal extraction. In conclusion, assisted calving with fetal extraction causes important metabolic changes for the dam and calf. Conversely, the practice of oxytocin and calcium infusion for hypotonic cows has no harmful effects on metabolic balance and can be safely employed as a medical treatment.

Effect of dystocia and treatment with oxytocin on neonatal calf vitality and acid-base, electrolyte and haematological status.

Under adverse obstetrical conditions, appropriate supervision and assistance during the immediate neonatal period are of the utmost importance, especially for weak calves. The aim of this study was to establish the effects of dystocia and oxytocin infusion on neonatal vitality, acid-base balance, and electrolyte and haematological homeostasis of dairy calves. Data were collected for 30 Holstein calves which were allocated to three groups: normal calving (n = 10); dystocia with mild to severe obstetric assistance (n = 10); and uterine inertia treated with oxytocin (n = 10). All 30 calves exhibited normothermia at birth, but had a significant decrease in body temperature after 60 min. Dystocic calves had lower Apgar scores than calves in the other two groups, and had respiratory and metabolic acidosis. Calves from normal calvings had normal blood pH, but base excess below the reference range. The mean partial pressure (Pa) of oxygen of calves whose dam had been treated with oxytocin was lower than that of calves from normal calvings. In all experimental groups, there was improvement in metabolic status in the first 60 min postpartum as PaCO2 values significantly decreased. All calves had normonatraemia, normokalaemia and normochloridaemia during the study period, but calves born to dams treated with oxytocin had a higher sodium concentration than those in the two other groups.

The oxidative stress, antioxidant profile and acid-base status in preterm and term canine neonates.

During the initiation of neonatal pulmonary respiration, there is an exponential increase in reactive oxygen species that must be scavenged by antioxidant defences. However, neonate and preterm newborns are known to possess immature antioxidant mechanisms to neutralize these toxic effects. The purposes of this study were to compare the development of antioxidant system between preterm and term canine neonates and to evaluate the magnitude of acid-base balance during the initial 4 h of life. A prospective study was conducted involving 18 neonatal puppies assigned to Term Group (63 days of gestation; n = 5), Preterm-57 Group (57 days of gestation; n = 8) and Preterm-55 Group (55 days of gestation; n = 5). Neonates were physically examined through Apgar score and venous haemogasometry within 5 min, 2 and 4 h after birth. No difference on amniotic fluid and serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and the marker of oxidative stress (thiobarbituric acid reactive substances; TBARS) was verified. Irrespective of prematurity, all neonates presented low vitality, hypothermia, acidosis, hypoxaemia and hypercapnia at birth. However, term puppies clinically evolved more rapidly than preterm newborns. During the course of the study, premature neonates presented more severe complications, such as prolonged hypoxaemia and even death. In conclusion, premature puppies have no signs of immature enzymatic mechanisms for controlling oxidative stress, although SOD and GPx may participate in achieving acid-base balance. Aside from initial unremarkable symptoms, premature puppies should be carefully followed up, as they are at high risk of succumbing to odds of prematurity.