Učinak temperature razrjeđivanja dvaju različitih razrjeđivača na kvalitetu sperme nerasta

This study investigated the quality characteristics and the field fertility of boar semen after dilution with OptimIA, a common extender at 23 (n = 20, group A23) or at 30 °C (n = 20, group A30), and after dilution with OptimIA commercial extender at 23 °C (n = 20, group 23A) or with Androhep Plus, a membrane protective extender at 23 °C (n = 20, group 23B). Each sample of extended semen was stored (16-18 °C) and used for a double artificial insemination at 48 h and 72 h after its collection at the farm (n = 30 per group). The semen was assessed in the laboratory (kinetic parameters, morphology and DNA fragmentation) at collection (0 h) and at insemination hours (48 and 72 h). Most of the semen laboratory parameters deteriorated from 48 h to 72 h, regardless of dilution temperature or the use of the protective extender. However, in the special protective extender the percentages of rapid movement spermatozoa, VCL (curvilinear velocity), VAP (average path velocity) and WOB (wobble) did not differ between 48 h and 72 h. A lower farrowing rate was observed in the common extender group at 23 °C, and a lower number of live born piglets in the protective extender group compared to the other two groups. In conclusion, one step dilution of boar semen at 23 °C compared to dilution at 30 °C did not dramatically affect its in vitro quality characteristics after 72 h of storage, although field fertility was negatively influenced. Some of these negative effects can be compensated for by the use of a membrane protective extender.Istražena je kvaliteta i plodnost nerastove sperme u terenskim uvjetima nakon razrjeđivanja s dva različita razrjeđivača: OptimaIA – standardni razrjeđivač na 23 °C (oznaka skupine A23, n = 20) ili na 30 °C (oznaka skupine A30, n = 20) i OptimaIA - komercijalni razrjeđivač na 23 °C (oznaka skupine 23A, n = 20) ili sa zaštitnikom membrane Androhep Plus na 23 °C (oznaka skupine 23B, n = 20). Svaki uzorak razrijeđene sperme bio je pohranjen na 16-18 °C i korišten za dvokratno umjetno osjemenjivanje nakon 48 h i 72 h od prikupljanja na farmi (n = 30 po skupini). Sperma je u laboratoriju ocijenjena (pokazatelji pokretljivosti, morfologija i DNA fragmentacija) prilikom prikupljanja (0 h) i prilikom osjemenjivanja (48 h i 72 h). Većina pokazatelja je, bez obzira na temperature razrjeđivanja ili uporabu zaštitnog razrjeđivača, pokazala pogoršanje u laboratorijskim uvjetima od 48 h na 72 h. Ipak, kod posebnog zaštitnog razrjeđivača, razlike između 48 h i 72 h nisu utvrđene za postotak brzo pokretljivih spermija, valovitost gibanja, prosječnu brzinu i oscilirajuće pokretanje (treperenje). U usporedbi s ostalim dvjema skupinama, niža stopa oprasivosti opažena je kod primjene standardnog razrjeđivača na 23 °C, a niži broj živorođenih odojaka opažen je nakon primjene zaštitnog razrjeđivača. Zaključno, iako postoji negativni utjecaj na plodnost u terenskim uvjetima, nakon 72 sata pohranjivanja, jedan korak razrjeđivanja nerastove sperme na 23 °C, u usporedbi s 30 °C, ne utječe dramatično na njezinu kvalitetu in vitro. Neki od negativnih utjecaja mogu se nadomjestiti uporabom razrjeđivača koji štite membranu spermija

Plasminogen activator activity in the porcine oviduct during the oestrous cycle

The mammalian oviduct is a dynamic tissue, which lies under the influence of ovarian steroids and produces proteins that affect various stages of fertilization and post-fertilization events. In this study, expression of urokinase-type plasminogen activator (u-PA mRNA) and plasminogen activator activity (PAA) were examined in porcine oviducts by reverse transcription and polymerase chain reaction (RT-PCR) and activity assays, respectively. For this purpose, oviducts were collected from Landrace cycling sows and divided into three segments (isthmus, ampulla, infundibulum). Different concentrations of u-PA mRNA were detected in the three segments following the pattern isthmus > ampulla > infundibulum and this pattern was maintained during the oestrous cycle. On the contrary, the highest PAA was measured in the ampulla compared to the isthmus and the infundibulum and the highest ampullary PAA was detected during the first 2 days of the oestrous cycle. The different regulation of u-PA mRNA expression and PAA is probably due to the existence of PA inhibitors. Recent observations suggest that PAI-1, the main inhibitor of PAs, shows greater expression in the isthmus compared to the ampulla and the local generation of plasmin is inhibited. The latter may be related to observations that spermatozoa are quiescent in the isthmus before fertilization. This study supports the suggestion that urokinase-type plasminogen activator has a biological role within the porcine oviduct, especially at or near the time of fertilization. (c) 2005 Elsevier Inc. All rights reserved

Učinak temperature razrjeđivanja dvaju različitih razrjeđivača na kvalitetu sperme nerasta

This study investigated the quality characteristics and the field fertility of boar semen after dilution with OptimIA, a common extender at 23 (n = 20, group A23) or at 30 °C (n = 20, group A30), and after dilution with OptimIA commercial extender at 23 °C (n = 20, group 23A) or with Androhep Plus, a membrane protective extender at 23 °C (n = 20, group 23B). Each sample of extended semen was stored (16-18 °C) and used for a double artificial insemination at 48 h and 72 h after its collection at the farm (n = 30 per group). The semen was assessed in the laboratory (kinetic parameters, morphology and DNA fragmentation) at collection (0 h) and at insemination hours (48 and 72 h). Most of the semen laboratory parameters deteriorated from 48 h to 72 h, regardless of dilution temperature or the use of the protective extender. However, in the special protective extender the percentages of rapid movement spermatozoa, VCL (curvilinear velocity), VAP (average path velocity) and WOB (wobble) did not differ between 48 h and 72 h. A lower farrowing rate was observed in the common extender group at 23 °C, and a lower number of live born piglets in the protective extender group compared to the other two groups. In conclusion, one step dilution of boar semen at 23 °C compared to dilution at 30 °C did not dramatically affect its in vitro quality characteristics after 72 h of storage, although field fertility was negatively influenced. Some of these negative effects can be compensated for by the use of a membrane protective extender.Istražena je kvaliteta i plodnost nerastove sperme u terenskim uvjetima nakon razrjeđivanja s dva različita razrjeđivača: OptimaIA – standardni razrjeđivač na 23 °C (oznaka skupine A23, n = 20) ili na 30 °C (oznaka skupine A30, n = 20) i OptimaIA - komercijalni razrjeđivač na 23 °C (oznaka skupine 23A, n = 20) ili sa zaštitnikom membrane Androhep Plus na 23 °C (oznaka skupine 23B, n = 20). Svaki uzorak razrijeđene sperme bio je pohranjen na 16-18 °C i korišten za dvokratno umjetno osjemenjivanje nakon 48 h i 72 h od prikupljanja na farmi (n = 30 po skupini). Sperma je u laboratoriju ocijenjena (pokazatelji pokretljivosti, morfologija i DNA fragmentacija) prilikom prikupljanja (0 h) i prilikom osjemenjivanja (48 h i 72 h). Većina pokazatelja je, bez obzira na temperature razrjeđivanja ili uporabu zaštitnog razrjeđivača, pokazala pogoršanje u laboratorijskim uvjetima od 48 h na 72 h. Ipak, kod posebnog zaštitnog razrjeđivača, razlike između 48 h i 72 h nisu utvrđene za postotak brzo pokretljivih spermija, valovitost gibanja, prosječnu brzinu i oscilirajuće pokretanje (treperenje). U usporedbi s ostalim dvjema skupinama, niža stopa oprasivosti opažena je kod primjene standardnog razrjeđivača na 23 °C, a niži broj živorođenih odojaka opažen je nakon primjene zaštitnog razrjeđivača. Zaključno, iako postoji negativni utjecaj na plodnost u terenskim uvjetima, nakon 72 sata pohranjivanja, jedan korak razrjeđivanja nerastove sperme na 23 °C, u usporedbi s 30 °C, ne utječe dramatično na njezinu kvalitetu in vitro. Neki od negativnih utjecaja mogu se nadomjestiti uporabom razrjeđivača koji štite membranu spermija

Relationship between cumulus cell apoptosis, progesterone production and porcine oocyte developmental competence: temporal effects of follicular fluid during IVM

The objective of the present study was to determine the temporal effects of sow follicular fluid (FF) in vitro on cumulus cell viability and function, as well as oocyte nuclear and cytoplasmic maturation. Cumulus–oocyte complexes (COCs) recovered from the ovaries of prepubertal pigs were matured in medium with (+FF) or without (–FF) follicular fluid for the first 22 h of IVM. At 22 h of IVM, each group of COCs was then transferred to medium with or without FF and matured for another 22 h, forming four treatment groups (–FF/–FF, –FF/+FF, +FF/–FF and +FF/+FF). The concentration of progesterone in spent IVM medium and the incidence of cumulus cell apoptosis in individual COCs were determined at 22 and 44 h of IVM. Cumulus expansion was also recorded at 44 h of IVM. Finally, the ability of oocytes to complete meiosis to the MII stage and form blastocysts after IVF and embryo culture was assessed. Maturation with FF for part or the whole of IVM increased cumulus expansion and progesterone production and decreased the incidence of cumulus cell apoptosis compared with the –FF/–FF group (P < 0.05). The changes were greatest for the +FF/+FF group and intermediate for the –FF/+FF and +FF/–FF groups. Regression analysis revealed a negative association between cumulus cell progesterone production and the incidence of cumulus cell apoptosis (P < 0.001). Meiotic maturation was enhanced when FF was present during the first half of IVM. Oocytes matured in the presence of FF during the first and/or second half of IVM displayed an increased ability to form blastocysts compared with the –FF/–FF group (P < 0.05). The extent of the increase was similar for all FF-supplemented groups. The results show that FF exerts several beneficial effects at different times during IVM and suggest that a major role of FF is to provide protection from oxidative stress. We propose that the incidence of cumulus cell apoptosis in COCs must be kept below a certain threshold to ensure adequate functionality, including steroidogenic activity, is maintained for the acquisition of oocyte developmental competence.Christopher G. Grupen and David T. Armstron

Effects of dietary vitamin A intake on acrosin- and plasminogen-activator activity of ram spermatozoa

Acrosin and plasminogen activators are proteolytic enzymes of ram spermatozoa that play an essential role in the induction of the acrosome reaction, as well as the binding of spermatozoa to the oocyte and their penetration through the layers that surround the oocyte. Since vitamin A can alter gene expression in various tissues, testis included, this study was undertaken to evaluate the possible effect of vitamin A intake on acrosin-and plasminogen-activator activity. During a 20-week experiment, 15 rams of the Greek breed Karagouniki, divided to three groups, received different amounts of vitamin A per os in retinyl acetate capsules (group A, controls, 12 500 iu/animal per day; group B, 50 000 iu/animal per day; group C, 0 iu/animal per day up to the 13th week, then 150 000 iu/animal per day until the end of the experiment). Acrosin- and plasminogen-activator activity were determined by spectrophotometric methods. Vitamin A was determined in blood plasma by HPLC. No statistical differences were detected regarding the body weight of the rams or the qualitative and quantitative parameters of their ejaculate throughout the whole experiment. No statistically significant alterations of enzyme activity were detected in group B. In group C, both enzyme activities started declining in week 9. Compared with controls, maximum reduction for acrosin was 49% on week 11 and for plasminogen activators 51 % in week 14. Activities returned to normal rates after vitamin A resupplementation. To date, the main result of vitamin A deficiency was known to be arrest of spermatogenesis and testicular degeneration. A new role for vitamin A may be suggested, since it can influence factors related to male reproductive ability before spermatogenesis is affected