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1.
Reprod Domest Anim ; 50(1): 112-20, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25405906

RESUMO

Plasminogen activators/Plasmin system plays pivotal role in regulating reproductive functions of mammals. Here, we examined the effects of modification of in vitro fertilization medium (IVF medium) with the addition of tissue-type plasminogen activator (t-PA), on bovine embryo development and quality, assessed by quantification of expression of various genes related to metabolism, oxidation, implantation and apoptosis. In addition, plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI) were measured in the spent media. After conventional IVM, 2016 cumulus-oocyte complexes (COCs) were divided into four groups with modified composition of the IVF medium containing t-PA and/or its inhibitor epsilon-aminocaproic acid (control, t-PA, t-PA+ε-ACA, ε-ACA). Presumptive zygotes were cultured for 8 days in synthetic oviductal fluid (SOF) medium; gene expression studies were carried out on morulae and blastocysts. t-PA alone significantly suppressed cleavage and blastocyst formation rates, but this effect was neutralized by the addition of ε-ACA. PAA in the treated group was significantly reduced by ε-ACA, but without total elimination. Significant differences were detected in the expression of genes related to apoptosis and/or cell cycle arrest (BAX, BCL2L1, KAT2B) between embryos produced in t-PA-modified media and controls, giving an overall notion that the inferior developmental competence of treated embryos may be attributed to apoptotic phenomena induced by t-PA. In conclusion, it appears that excessive t-PA content in the IVF media, suppresses blastocyst formation rate, possibly due to induction of apoptotic phenomena.


Assuntos
Bovinos/embriologia , Desenvolvimento Embrionário/efeitos dos fármacos , Fertilização in vitro/veterinária , Expressão Gênica/efeitos dos fármacos , Ativador de Plasminogênio Tecidual/farmacologia , Animais , Apoptose/genética , Blastocisto/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Meios de Cultura , Técnicas de Cultura Embrionária , Implantação do Embrião/genética , Feminino , Fertilização in vitro/métodos , Técnicas de Maturação in Vitro de Oócitos , Masculino , Metabolismo/genética , Mórula/metabolismo , Oxirredução , Ativadores de Plasminogênio/análise , Inativadores de Plasminogênio/análise , Ativador de Plasminogênio Tecidual/efeitos adversos , Ativador de Plasminogênio Tecidual/análise
2.
J Vet Pharmacol Ther ; 32(5): 457-64, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19754912

RESUMO

The pharmacokinetics of amoxicillin (AMX) were investigated in sheep following intravenous (i.v.) and intramuscular (i.m) injection, comparing two different drug formulations, a conventional and a long-acting AMX-trihydrate suspension. For the i.m. application two different injections sites, the neck area and the hind limb were used to identify possible differences in the kinetic parameters related to the site of injection. A three-compartment open model could best describe AMX disposition after i.v. administration. Data analysis after i.m. administration of the conventional suspension at both injection sites revealed the occurrence of a flip-flop phenomenon, clearly indicating that absorption of AMX is the rate-limiting step of its overall disposition. A moderate effect of the injection site was observed with a tendency for the neck area to be advantageous, mainly in terms of rate rather than extent of absorption. Injection of the long-acting formulation led to a focal depot formation, thus yielding lower but remarkably prolonged serum AMX levels reflected in the respective terminal half-lives. The concentration-time profile of AMX after administration of the long-acting formulation was less affected by the injection site, but the low serum levels justify its use only in cases in which a high susceptibility of the involved bacterial population is confirmed.


Assuntos
Amoxicilina/administração & dosagem , Antibacterianos/administração & dosagem , Amoxicilina/sangue , Amoxicilina/farmacocinética , Animais , Antibacterianos/sangue , Antibacterianos/farmacocinética , Preparações de Ação Retardada , Membro Posterior , Injeções Intramusculares/veterinária , Injeções Intravenosas/veterinária , Masculino , Pescoço , Ligação Proteica , Ovinos/metabolismo , Suspensões
3.
J BUON ; 14(3): 463-72, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19810140

RESUMO

PURPOSE: In this study we evaluated the clinical usefulness of serum pro-I collagen peptide (PICP) and I collagen telopeptide (ICTP) as indicators of early bone metastases in patients with breast (BC), lung (LC), urinary bladder (UBC) and prostate cancer (PC). PATIENTS AND METHODS: 305 patients were examined. 145 had histologically confirmed BC (92 with bone metastases), 20 UBC (6 with bone metastases), 11 LC (3 with bone metastases) and 129 PC (68 with bone metastases). In BC patients we compared the PICP and ICTP levels with those of CA 15-3, CEA and bone scintigraphy. Patients with LC and UBC had PICP and ICTP measurements, PC patients had serum PICP, prostate specific antigen (PSA) measurements and bone scans. 104 healthy individuals served as controls. RESULTS: ICTP and CA 15-3 levels were significantly higher in patients with BC and bone metastases in comparison to patients without metastases (p <0.05), while PICP and CEA were only marginally higher. Significant correlation was observed between existence of bone metastases and ICTP levels (p <0.05). The sensitivity of PICP, ICTP, CEA and CA 15-3 was 28.1, 48.6, 42, and 78%, respectively and specificity was 83.9, 94, 65 and 86%, respectively. ICTP and CA 15-3 were the most reliable markers for early diagnosis of bone metastases in BC. PICP alone or with ICTP were not sensitive enough. Only CA 15-3 showed sensitivity 78% and specificity 86%. When combined CA 15-3, ICTP and CEA the sensitivity and specificity increased to 82% and 96%, respectively. Furthermore, PICP and PSA levels were significantly higher in patients with PC and bone metastases in comparison to patients with benign prostate hyperplasia (BPH) (p <0.0001) or in patients with PC without bone metastases (p <0.0005 for PICP and p <0.0001 for PSA). The co-evaluation of PICP and PSA improved the sensitivity (78%), specificity (96%), accuracy (97%) and positive predictive value (97%). In LC patients, ICTP levels differed significantly between patients with and without bone metastases (p=0.025). In UBC patients, PICP levels differed significantly between patients with and without bone metastases (p=0.017). CONCLUSION: ICTP and CA 15-3 are the most reliable markers for early diagnosis of bone metastases in BC patients. PICP could be useful for diagnosing early bone metastases of PC and combined with PSA and bone scan can be an additional tool in the follow-up of PC patients. For LC patients, ICTP showed a significant difference in the discrimination of patients with and without bone metastases. In UBC patients, PICP showed a significant difference in the discrimination of patients with and without bone metastases.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Colágeno Tipo I/metabolismo , Adulto , Idoso , Neoplasias da Mama/patologia , Antígeno Carcinoembrionário/metabolismo , Feminino , Humanos , Ensaio Imunorradiométrico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Mucina-1/metabolismo , Metástase Neoplásica , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/patologia , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão , Neoplasias da Bexiga Urinária/patologia
4.
Reprod Domest Anim ; 43(2): 153-6, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18325004

RESUMO

The effect of porcine or ovine FSH on the maturation rate of porcine oocytes and on the time course of meiotic progression was studied. Groups of 20 grade-A cumulus oocyte complexes, aspirated from slaughterhouse cycling-gilt ovaries, were cultured in vitro in 400 mul of Modified Parker's Medium supplemented with oestrous cow serum and porcine FSH (Folltropin(R)-V, 0.50 mg/ml) or ovine FSH (Ovagen(TM), 0.44 iu/ml), in four-well dishes under mineral oil, at 38.5 degrees C, 5% CO(2) in humidified air. At the end of each 3-h interval, from 3 to 42 h of culture, the nuclear status of oocytes was assessed microscopically (1000x), after fixation (methanol/acetic acid: 3/1) and orcein (2%) staining. Oocytes were classified as (i) immature (IMM), i.e. oocytes at germinal vesicle stage, germinal vesicle break down and prophase I, (ii) metaphase I (MI) and (iii) metaphase II (MII), i.e. oocytes at anaphase I, telophase I and metaphase II. Data were analysed using regression analysis, chi-square and t-test. Nuclear status was assessed in 1610 oocytes (porcine FSH: 787, ovine FSH: 823). Most of the oocytes were at MI from 24 to 33 h (porcine FSH 60.27%, ovine FSH 42.80%, p < 0.001) and at MII from 36 to 42 h (porcine FSH 80.38%, ovine FSH 67.45%, p < 0.01) of culture. Significantly higher maturation rate was observed in porcine FSH than in ovine FSH treated oocytes (86.69 +/- 12.97%, 71.34 +/- 9.86%, mean +/- SD, p < 0.05), after 42 h of culture. In conclusion, under the specific culture conditions, porcine FSH seems to support pig oocyte maturation better than ovine FSH.


Assuntos
Hormônio Foliculoestimulante/farmacologia , Oócitos/efeitos dos fármacos , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/fisiologia , Feminino , Técnicas In Vitro , Oócitos/fisiologia , Maturidade Sexual , Ovinos , Suínos
5.
Reprod Toxicol ; 17(2): 185-90, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12642151

RESUMO

Organochlorine pesticides and polychlorinated biphenyls are widely used in agriculture and industry, respectively. The present study assessed the burden of environmental pollutants in the follicular fluid of farm animals (cattle, sheep, goats, and pigs). An analytical method combining a solid-phase extraction with (C(18)) for clean-up and GC-electron capture detection using a capillary column was implemented for isolation and determination of organochlorine pesticides and polychlorinated biphenyls (PCBs). Of the organochlorine pesticides, hexachlorobenzene (HCB), hexachlorocyclohexane (HCH, alpha-, beta-, and gamma-isomers), dieldrin, heptachlor epoxide, and the DDT-related chemicals (o,p'-DDE, p,p'-DDE, p,p'-DDD, p,p'-DDT) were detected and of the PCBs, the congeners PCB-52, -101, -138, -153, and -180 were detected. In all species of farm animals, the most frequently detected pollutant was gamma-HCH (90-100% of samples) followed by HCB (80-100%), and p,p'-DDE (75-90.91%). Species differences in the concentrations of HCB, beta-HCH, heptachlor epoxide, and DDT-related chemicals in follicular fluid were noted as well as differences in the concentrations of some pollutants within the same species.


Assuntos
Animais Domésticos/metabolismo , Poluentes Ambientais/análise , Líquido Folicular/química , Animais , Bovinos , DDT/análogos & derivados , DDT/análise , Feminino , Cabras , Hexaclorobenzeno/análise , Hexaclorocicloexano/análise , Inseticidas/análise , Bifenilos Policlorados/análise , Ovinos , Suínos
6.
Reprod Toxicol ; 17(4): 439-45, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12849855

RESUMO

Organochlorine pesticides and polychlorinated biphenyls are widely used in agriculture and industry, respectively, and may affect male reproduction function. Although several pollutants have been detected in human semen, similar studies in farm animals have not appeared. In the present study, the semen of bulls, rams, goats, and boars was assayed for the organochlorine pesticides hexachlorobenzene (HCB), hexachlorocyclohexane (HCH, alpha-, beta-, and gamma-isomers), dieldrin, and heptachlor epoxide, for DDT-related chemicals (o,p'-DDE, p,p'-DDE, p,p'-DDD, p,p'-DDT), and for the PCBs congeners (PCB-52, -101, -138, -150, and -180). In all species of farm animals, the most frequently detected pollutants were p,p'-DDE (80-100% of samples), HCB (73.9-100%), and gamma-HCH (69.6-100%). Species differences in the concentrations of HCB, alpha-, beta-, and gamma-HCH, dieldrin, p,p'-DDE, p,p'-DDD, and PCBs were noted as well as differences in the concentrations of some isomers of HCH, DDT-related chemicals, and PCB congeners in the same species.


Assuntos
Animais Domésticos/metabolismo , Poluentes Ambientais/análise , Animais , Bovinos , Cromatografia Gasosa , Cabras , Inseticidas/análise , Inseticidas/química , Masculino , Bifenilos Policlorados/análise , Bifenilos Policlorados/química , Sêmen , Ovinos , Especificidade da Espécie , Estereoisomerismo , Suínos
7.
J Pharm Biomed Anal ; 35(5): 1191-202, 2004 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-15336364

RESUMO

A new analytical method for the simultaneous quantitative determination of albendazole metabolites in sheep spermatozoa and seminal plasma at levels down to 46.5 ng/mL for albendazole sulphoxide (ABZ-SO), 7.5 ng/mL for albendazole sulphone (ABZ-SO2) and 12 ng/mL for albendazole 2-aminosulphone (ABZ-SO2NH2) has been developed. Analytes were extracted from alkalinized samples with ethyl acetate. Separation was carried out on a C18 column in the presence of tetra-n-butylammonium (TBA) hydrogen sulphate and octanesulphonate sodium (OCT), as ion-pair agents. Fluorometric detection was performed with excitation and emission wavelengths set at 290 and 320 nm, respectively. Accuracy data showed overall recoveries (+/-S.E.M.) of 83.1+/-1.2% for ABZ-SO, 98.8+/-0.6% for ABZ-SO2 and 85.3+/-0.7% for ABZ-SO2NH2, in spermatozoa. Respective values in seminal plasma were 88.0+/-0.9%, 97.7+/-0.5% and 93.2+/-1.7%. Precision data suggested coefficient of variation (CV%) values lower than 5.9% for spermatozoa and 3.8% for seminal plasma. The method was successfully applied for the determination of the three albendazole metabolites in semen samples collected from rams that had been orally administered albendazole.


Assuntos
Albendazol/análogos & derivados , Albendazol/análise , Sêmen/química , Espermatozoides/química , Animais , Anti-Helmínticos/análise , Calibragem , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Congelamento , Masculino , Estrutura Molecular , Ovinos
8.
Anim Reprod Sci ; 80(1-2): 59-67, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15036515

RESUMO

Synchronisation of oestrus in Karagouniki ewes by administration of the standard dose of progesterone results in lower fertility than observed when these ewes ovulate naturally. This suggests that the optimum dose of progesterone may be breed dependent. The exogenous progesterone may perturb the concentrations of oestradiol-17beta and progesterone in blood plasma and the oviductal wall. This possibility was investigated using Karagouniki ewes allocated at random to three treatments (n=4 per treatment). Ewes were allowed to exhibit natural oestrus (N) or oestrus was synchronised by administration of 250 mg (LP) or 375 mg (HP) progesterone (subcutaneous implants) followed by PMSG at 8 mg/kg live weight i.m. 14 days later. Oestrus was observed using teaser rams. Blood samples were collected for plasma oestradiol-17beta and progesterone assay from the onset to the end of oestrus at 2 h intervals. The uterus of each ewe was recovered at the end of oestrus and samples of the oviductal wall were taken from both oviducts and prepared, separately, for progesterone and oestradiol-17beta assay. Statistical analysis was performed using univariate analysis of variance. Plasma oestradiol-17beta concentrations from the onset to the end of oestrus were highest for N ewes and lowest for HP ewes with the values for LP ewes occupying an intermediate position. The differences were significant (P<0.05) between HP and the other two treatments from 4 to 12 h after the onset of oestrus and then between all treatments until the end of oestrus. Plasma progesterone levels were similar and fairly constant from the onset to the end of oestrus for N and LP. The plasma progesterone levels for HP were significantly (P<0.05) higher than for the other two treatments throughout oestrus. In oviductal wall samples, the oestradiol-17beta concentration was significantly (P<0.05) higher for N ewes than for synchronised ewes and the levels were similar for LP and HP ewes. The concentration of oestradiol-17beta differed (P<0.05) between right and left oviducts for N ewes but not for ewes of either of the synchronised oestrus treatments. Progesterone concentrations in oviductal wall samples were highest (P<0.05) for HP ewes and the values for N and LP ewes were similar. The concentration of progesterone did not differ between right and left oviductal wall samples within treatments. It was concluded that the higher dose of exogenous progesterone perturbed the levels of oestradiol-17beta and progesterone in blood plasma and the oviductal wall, and this could explain the lower levels of fertility (relative to naturally occurring oestrus) observed when this protocol is used for Karagouniki ewes in practice.


Assuntos
Estradiol/sangue , Sincronização do Estro , Estro/fisiologia , Tubas Uterinas/química , Progesterona/sangue , Ovinos/metabolismo , Animais , Estradiol/análise , Feminino , Progesterona/análise , Ovinos/sangue
9.
Anim Reprod Sci ; 138(3-4): 180-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23523233

RESUMO

Blood concentrations of progesterone, FSH and oestradiol in Karagouniko ewes subjected to laparoscopic ovum pick-up (OPU) at specific stages of induced oestrous cycle, were measured. Twenty-four cyclic ewes were randomly allocated into four equal groups (A, B, C and D). Oestrus was synchronized with progestagen intravaginal sponges and detected by teaser rams (oestrus: day 0). In group A, during the induced oestrous cycle, OPU was performed on days 4, 9 and 14 (sessions A1, A2 and A3, respectively). In group B and group D, OPU was performed once, on day 9 and 14, respectively. In group C (controls), endoscopic observation of follicular population was performed three times, as in group A. Starting at sponge removal, progesterone was measured in blood samples collected on 22 daily occasions and oestradiol in samples collected on 27 occasions collected at various time-points starting 2h before to 24h after OPU. Follicular populations did not differ among A1, A2, A3 or between C1, C2, C3 and A1, A2, A3 or A1, B, D, respectively. Oocytes of better quality (category '1' or '2') were collected at A3 session compared with A1 (P<0.05). Progesterone concentration and oestrous cycle length did not differ among groups. Decreased oestradiol concentrations followed by FSH increase were recorded 3-5h after OPU. The results confirm the regulatory role of oestradiol on FSH secretion. The quality of collected oocytes was improved in subsequent pick-up sessions in the oestrous cycle. Moreover, OPU at specific stages of the luteal phase of the cycle, even when applied repeatedly, do not affect the normal oestrous cycle length of ewes.


Assuntos
Ciclo Estral/sangue , Hormônios/sangue , Recuperação de Oócitos/métodos , Folículo Ovariano/fisiologia , Carneiro Doméstico , Animais , Contagem de Células , Tamanho Celular , Estradiol/sangue , Ciclo Estral/fisiologia , Feminino , Hormônio Foliculoestimulante/sangue , Hormônios/metabolismo , Recuperação de Oócitos/estatística & dados numéricos , Recuperação de Oócitos/veterinária , Oócitos/citologia , Óvulo/citologia , Progesterona/sangue , Carneiro Doméstico/sangue , Carneiro Doméstico/fisiologia
10.
Reprod Domest Anim ; 40(1): 6-10, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15654994

RESUMO

A novel method for oestrus-ovulation synchronization in sheep followed by fixed time insemination is presented herewith. Mature dry ewes (n = 28) of Karagouniko breed being at an unknown stage of the oestrous cycle, were used during the middle of breeding season. The treatment protocol consisted of an initial administration of a GnRH analogue followed 5 days later by a prostaglandin F2alpha injection. Thirty-six hours later a second GnRH injection was administered to synchronize ovulation, and laparoscopic intrauterine insemination was performed 12-14 h later. Three days after insemination, fertile rams were introduced into the flock twice daily and oestrus-mating detection was carried out. For progesterone (P(4)) determination, blood samples were collected on alternate days, starting 2 days before the first GnRH injection and continuing for 17 days after insemination. An additional sample was taken on the day of insemination. Pregnancy diagnosis was carried out by trans-abdominal ultrasonography. Fourteen ewes (50%) conceived at insemination and maintained pregnancy; from the remainder 14 ewes 10 became pregnant at natural service, while four, although they mated at least two to three times, failed to conceive. In response to the first GnRH, P(4) concentration increased at higher levels in ewes that conceived at AI compared with those that failed to conceive (47.54 and 22.44%, respectively; p < 0.05). Significant differences (p < 0.05) in mean P(4) concentration between pregnant and non-pregnant animals were detected 1 day before AI (0.17 +/- 0.06 and 0.26 +/- 0.14 ng/ml, respectively) on the day of AI (0.15 +/- 0.04 and 0.24 +/- 0.08 ng/ml, respectively) as well as 9 and 11 days thereafter (0.48 +/- 0.12 and 0.38 +/- 0.12 ng/ml; 0.68 +/- 0.14 and 0.50 +/- 0.18 ng/ml, respectively). These results indicate that using the proposed protocol, an acceptable conception rate can be achieved which could be further improved by modifying the time intervals between interventions.


Assuntos
Sincronização do Estro/métodos , Fertilização , Inseminação Artificial/veterinária , Ovulação/fisiologia , Ovinos/fisiologia , Animais , Dinoprosta/administração & dosagem , Esquema de Medicação , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio Liberador de Gonadotropina/análogos & derivados , Injeções Intramusculares/veterinária , Inseminação Artificial/métodos , Gravidez
11.
Scand J Haematol ; 37(5): 404-10, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2856853

RESUMO

Some parameters of haem synthesis were estimated in 60 uraemic patients (30 non-dialysed, 30 dialysed) and in 30 matched controls. Serum delta-aminolaevulinic acid and erythrocyte coproporphyrin and protoprophyrin were found significantly higher in the non-dialysed uraemics than in the controls. Erythrocyte delta-aminolaevulinic acid dehydrase (ALA-D) activity was 498 +/- 174 mumol/h.l in the non-dialysed patients, 321 +/- 146 in the dialysed (just before haemodialysis) and 833 +/- 281 in the healthy controls, the differences between these groups all being statistically significant (p less than 0.001). After haemodialysis the enzymic activity in the dialysed group increased significantly (380 +/- 167, p less than 0.001), but remained lower than normal (p less than 0.001). A similar pattern - although with less statistical significance of the differences between groups - was observed concerning erythrocyte uroporphyrinogen I synthase activity. Incubation of normal erythrocytes with uraemic plasma resulted in a considerable decrease of their ALA-D activity (from 830 +/- 263 to 616 +/- 126) while incubation of uraemic erythrocytes with normal plasma increased their ALA-D (from 384 +/- 139 to 494 +/- 77). Addition of zinc in the haemolysate caused a similar induction of ALA-D in both controls and uraemics. The zinc-induced uraemic ALA-D practically reached normal levels. The mechanism of enzymic depression and the possible role of elevated delta-aminolaevulinic acid concentrations (to which depressed ALA-D activity considerably contributes) in the pathogenesis of the neurologic manifestations of uraemia, are discussed.


Assuntos
Heme/biossíntese , Diálise Renal , Uremia/metabolismo , Eritrócitos/enzimologia , Feminino , Humanos , Hidroximetilbilano Sintase/metabolismo , Masculino , Pessoa de Meia-Idade , Sintase do Porfobilinogênio/sangue , Uremia/enzimologia , Uremia/terapia , Zinco/farmacologia
12.
Andrologia ; 32(2): 107-14, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10755193

RESUMO

In a series of consecutive blood sampling in 15 days intervals over 15 weeks after implantation of melatonin in rams an increased mean value, basal level and number of peaks of testosterone was observed in samples of the third fortnight (45th day). This increase was greater in the autumn (breeding season) than in spring (non-breeding season). Total acrosin activity in spermatozoa was increased between days 35-56 (autumn) and days 49-70 (spring) after implantation and the relative increase was higher in autumn than in spring. The increase of acrosin activity was independent of the changes of testosterone. An increase of acrosin activity by melatonin, in cases of low activity, might improve fertilization rates in sheep not only during the breeding season, but also during the non-breeding season (after oestrus induction).


Assuntos
Acrosina/metabolismo , Melatonina/administração & dosagem , Ovinos/fisiologia , Espermatozoides/enzimologia , Testosterona/sangue , Animais , Implantes de Medicamento , Cinética , Masculino , Melatonina/farmacologia , Reprodução , Estações do Ano
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