Efficiency of GnRH-Loaded Chitosan Nanoparticles for Inducing LH Secretion and Fertile Ovulations in Protocols for Artificial Insemination in Rabbit Does.

Gonadotropin-releasing hormone (GnRH)-loaded chitosan nanoparticles (GnRH-ChNPs) were used at different doses and routes of administration to induce ovulation in rabbits as an attempt to improve artificial insemination (AI) procedures and outcomes. In this study, the characteristics (size, polydispersity, loading efficiency, and zeta-potential) of GnRH-ChNPs and the GnRH release pattern were determined in an in vitro study. A first in vivo study assessed the pituitary and ovarian response to different GnRH-ChNPs doses and routes of administration (two i.m. doses, Group HM = 0.4 µg and Group QM = 0.2 µg, and two intravaginal doses, Group HV = 4 µg and Group QV = 2 µg) against a control group (C) receiving bare GnRH (0.8 µg). The HM, QM, and HV treatments induced an earlier LH-surge (90 min) than that observed in group C (120 min), whilst the QV treatment failed to induce such LH surge. The number of ovulation points was similar among treatments, except for the QV treatment (no ovulation points). A second in vivo study was consequently developed to determine the hormonal (progesterone, P4, and estradiol, E2) profile and pregnancy outcomes of both HM and HV treatments against group C. The treatment HM, but not the treatment HV, showed adequate P4 and E2 concentrations, conception and parturition rates, litter size, litter weight, and viability rate at birth. Overall, the use of GnRH-ChNPs allows for a reduction in the conventional intramuscular GnRH dose to half without compromising fertility. However, the addition of GnRH-ChNPs to semen extenders, although successfully inducing ovulation, has negative impacts on fertility. Thus, more studies are needed to explore this point and allow further adjustments.

Electrostimulation with or without ultrasound-guidance in interscalene brachial plexus block for shoulder surgery.

In a prospective controlled trial to compare conventional interscalene brachial plexus block (ISBPB) using anatomic landmarks and electro-stimulation with a combined technique of ultrasound guidance followed by nerve stimulation, 60 patients were randomized into 2 matched equal groups: Group A using nerve stimulation (NS) alone and Group B using the combination of ultrasound and NS. The time to detect the plexus (3.9 ± 4 min in Group A and 3.3 ± 1.4 min in Group B) was not significantly different. We needed to reposition the needle once (n = 13) or twice (n = 4) in Group B. First-shot motor response was achieved in all but one patient in Group A; here we were only able to locate the plexus by use of ultrasound. None of the patients needed general anaesthesia. There were no significant differences between postoperative pain, motor power, or patient's satisfaction. ISBPB seems similarly effective using electro-stimulation and ultrasound if performed by experienced anesthesiologists.

In vitro gossypol induced spermatozoa motility alterations in rabbits.

The objectives of the present study were to: (i) examine the in vitro dose response of rabbit spermatozoa motility to the antifertility agent gossypol (GOS) and (ii) determine whether filtered (FIL) and unfiltered (UNFIL) GOS differ in their magnitude of effect. Rabbit semen belonging to adult males (n = 5; 12-14 months) were cultured with UNFIL GOS and FIL GOS (5% solution) and subsequently diluted (1:1-7) for analysis using a Computer Assisted Semen Analyzer (CASA) system in 5 time periods (0, 60, 120, 180 and 360 minutes). At Time 0, no significant change in rabbit spermatozoa motility (MOT) and progressive motility (PROG) with GOS FIL was noted, while increases were observed with GOS UNFIL. At Time 60, weak changes were noted for MOT and PROG. After 120 minutes of culture with both GOS FIL and GOS UNFIL, MOT and PROG decreased significantly in some experimental groups. However, no differences were recorded for both the parameters at Times 180 and 360, with the exception of PROG in the GOS UNFIL category (groups A, B, E, F and G), where a significant decrease was noticed. Detailed evaluation of the distance and velocity parameters revealed reduction in all these studied markers after 60 and 120 minutes of in vitro culture with both GOS FIL and GOS UNFIL, indirectly confirming the PROG decrease. Straightness (STR), linearity (LIN), wobble (WOB), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) mostly remained unaltered at all time periods for GOS FIL, where as some minor alterations were noticed in GOS UNFIL category for STR, LIN, WOB, ALH and BCF parameters at Time 0, 60 and 120. The present study confirms the dose and time dependent alterations of rabbit spermatozoa motility parameters by GOS. The GOS dynamics in our experiment shows that rabbit spermatozoa as a biological material can indicate a GOS inhibition of motility. Obtained data for the first time indicates a higher immobilizing potential of unfiltered GOS in comparison to filtered GOS in its inhibitory action of spermatozoa motility parameters in rabbits.

Reproductive toxicologic effects of gossypol on male rabbits: biochemical, enzymatic, and electrolytic properties of seminal plasma.

OBJECTIVE: To evaluate the effects of two sublethal doses of gossypol on biochemical, enzymatic, and electrolytic properties of male rabbit seminal plasma. DESIGN: Retrospective study. SETTING: A university-affiliated laboratory. ANIMAL(S): Fifteen adult male New Zealand white rabbits. INTERVENTION(S): Two sublethal doses of gossypol (4 and 20 mg per kilogram of body weight, every other day) were given orally. MAIN OUTCOME MEASURE(S): Biochemical, enzymatic, and electrolytic properties of male rabbit seminal plasma. RESULT(S): Seminal plasma total protein and albumin were statistically significantly increased by treatment with gossypol. Total lipids concentration was statistically significantly decreased by treatment with both doses of gossypol, whereas cholesterol was statistically significantly decreased by treatment with the low gossypol dose. Seminal plasma lactate dehydrogenase and alanine aminotransferase activities were statistically significantly decreased by treatment with the low dose of gossypol, whereas activities of these enzymes as well as of aspartate aminotransferase were statistically significantly increased by treatment with the high dose. Treatment with the high dose of gossypol statistically significantly reduced K+ concentration in the seminal plasma, whereas it statistically significantly increased Na+ and the Na+-K+ ratio. CONCLUSION(S): Seminal plasma values of total protein, total lipids, cholesterol, aspartate aminotransferase, and Na+ concentration returned to control levels after withdrawal of gossypol, whereas the effect of this drug on other parameters continued during the recovery period.