Inhibition of sperm motility by the volatile anesthetic halothane

Does exposure to inhalation anesthesia gases change the ratio of X-bearing sperms and Y-bearing Sperms? A worth exploring project into an uncharted domain

According to recent surveys performed in United States and India, anesthesia care providers were observed to have sired female offspring in a higher proportion than male offspring as their firstborn progeny; however, the reasons for the skew are not clear. Our hypothesis is that the underlying biological evidence may be elucidated by unraveling differences (if any) between the concentrations of X-bearing sperms and Y-bearing sperms in the semen samples obtained from males exposed to varied levels of anesthetics in their lifetimes. Therefore, the objectives of the envisaged study would be to conduct a three-stage investigative study on in-vitro human semen samples to determine (a) X-bearing sperms and Y-bearing sperms concentrations' ratio in male pediatric anesthesia care providers' semen samples, (b) changes in X-bearing sperms and Y-bearing sperms concentrations' ratios between the pre-rotation and post-rotation semen samples of male medical student volunteers/observers, and (c) changes in X-bearing sperms and Y-bearing sperms concentrations' ratios between the pre-operative and post-operative day-3 semen samples of male patients presenting for outpatient procedures under inhalational anesthesia. The expected outcomes would be (a) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-anesthesia day 3 sample as compared to the baseline preoperative sample, (b) linear and positive correlation of the anesthetic gas usage (exposure) with increased X-bearing sperms/Y-bearing sperms ratio in post-rotation sample as compared to the baseline sample, and (c) observation of high X-bearing sperms/Y-bearing sperms ratio in the pediatric anesthesia care providers. In summary, effects (if any) of occupational or personal exposure to inhalational anesthetic gases on the X-bearing sperms and Y-bearing sperms ratio is a worthy project wherein lots of questions that have arisen over decades could find the path to their definitive answers, based on envisaged laboratory investigations into this uncharted domain.

Inhibitory action of halothane on rat masculine sexual behavior and sperm motility

Adult male rats were exposed to inhale halothane in the following regime: 15 ppm/4 h/5 days/week/9 weeks. Sexual behavior observations and sperm motility test were made before halothane exposure (0 days) and at 15, 30, 45 and 60 days of exposure. Fifteen days after halothane exposure, this anesthetic inhibited the proportion of animals displaying ejaculation. In those animals ejaculating, halothane produced an inhibition of masculine sexual behavior reflected as an increase in the intromission latency, number of mounts and postejaculatory interval. At 30 days after exposure, only an increase in the intromission latency was observed. At 45 and 60 days, the inhibitory effect of halothane on sexual behavior disappeared. Similarly, at 15 and 30 days, but not at 45 or 60 days of halothane exposure, a reduced sperm motility was observed. Such transient effects of halothane suggest the development of tolerance to the inhibitory actions of this anesthetic on sexual behavior and sperm motility. These halothane effects are in line with an inhibition of masculine sexual behavior after stimulation of the GABAergic system.

Two molecular models of initial left-right asymmetry generation

Left-right (LR) asymmetry is a fascinating problem in embryonic morphogenesis. Recently, a pathway of genes has been identified which is involved in LR patterning in vertebrates. Although this work characterizes the interactions of several asymmetrically-expressed genes, it is still entirely unclear how such asymmetric expression is set up in the first place. There are two promising molecular candidates which may play a role is such a process: the motor protein dynein, and the gap junction protein connexin-43 (Cx43). We present two models, significantly supported by previous findings, which hypothesize that (a) dynein asymmetrically localizes LR determinants in individual cells to establish cell-autonomous LR biasing, and (b) asymmetric activity of Cx43 gap junctions within key cells sets up electric potentials in multicellular fields, thus establishing large-scale LR asymmetry.

Comparison of pregnancy rates following gamete intrafallopian transfer (GIFT) under general anesthesia with thiopental sodium or propofol

STUDY OBJECTIVE

To determine whether the pregnancy rate for gamete intrafallopian transfer (GIFT) patients who received thiopental sodium was different from the pregnancy rate for patients who received propofol for the induction of general anesthesia.

DESIGN

Retrospective review of clinical records.

SETTING

Private outpatient infertility clinic.

PATIENTS

Two hundred eighty-two consecutive GIFT procedures performed on 230 patients with infertility.

INTERVENTION

Patients undergoing GIFT were divided into two groups on the basis of whether they received thiopental or propofol for induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Clinical pregnancy following each GIFT procedure was assessed by multiple-serum beta human chorionic gonadotropin and ultrasound determinations. The pregnancy rates of 24.6% and 25.8% for the thiopental and propofol groups, respectively, were not significantly different.

CONCLUSIONS

The pregnancy rate following GIFT for patients given propofol for induction of general anesthesia did not differ from that for patients given thiopental.

General anesthesia for intrauterine placement of human conceptuses after in vitro fertilization

General anesthesia has been used for the replacement of human conceptuses after in vitro fertilization (IVF). Two adjuvants, enflurane and halothane, have been compared. Halothane significantly reduced the incidence of implantation compared to enflurane. In 356 replacements, the incidence of implantation for enflurane and halothane was 34 and 17%, respectively (P = 0.005). Sixty-four percent of all replacements had three conceptuses; the incidence of implantation for enflurane and halothane in this group was 43 and 19%, respectively (P = 0.002). The incidence of multiple pregnancy was similar for both anesthetic agents (20%) and the demise of implantation sacs 5 weeks postovulation was 11% for enflurane and 12% for halothane.

Effects of the volatile anesthetic halothane on fertilization and early development in the sea urchin Lytechinus variegatus: evidence that abnormal development is due to polyspermy

The volatile anesthetic halothane, when present at fertilization, dose-dependently increases the incidence of abnormally developing sea urchin embryos at the first cell division. Microscopic examinations of eggs stained with aceto-orcein or the DNA fluorochrome bisbenzimide and direct observations on isolated sperm aster complexes show that halothane induces polyspermy (multiple sperm entry) when present at fertilization. Experimental evidence suggests that anesthetic-induced polyspermy involves impairment of both the fast (electrically mediated) and slow (morphological) blocks to multiple sperm entry. These observations clearly show that relatively brief exposures to halothane at fertilization cause polyspermy and that this effect is almost certainly responsible for the ensuing abnormal development observed at the first cell division.