Effect of oestradiol delivered from a perioviducal device on ovum transport in mice

Silastic devices impregnated with oestradiol and blank devices were placed around both oviducts and around skeletal muscle bundles in the forelegs to attain local and systematic delivery, respectively. Another group of mice received an oestradiol-impregnated device around one oviduct and a blank device in the contralateral oviduct. Implantation of blank devices around the oviducts and in the forelegs did not alter ovum transport. Devices impregnated with oestradiol placed around both oviducts produced a dose-dependent delay of ovum transport, which was more pronounced than the effect of devices located in the forelegs. Oviducts receiving an oestradiol-loaded device had a larger retention of ova than did the contralateral oviducts receiving a blank device. These results demonstrate a direct action of oestradiol upon the oviduct to delay ovum transport in the mouse.     

Effects on pregnancy in mice of passive immunization against ovine LH and human chorionic gonadotrophin

Mice given daily i.p. injections of immunoglobulins against ovine LH on Days 3-7 of pregnancy were devoid of implantation sites on Day 8 whereas mice treated with antibodies to hCG had embryos of normal number and appearance on Day 8. These antibody treatments reduced the mean +/- s.d. serum progesterone concentrations from 65.4 +/- 15.3 ng/ml (control globulins) to 8.6 +/- 4.9 ng/ml (anti-LH) and 9.2 +/- 3.1 ng/ml (anti-hCG) on Day 8 and had no differential effect on serum oestrogen levels on Day 4. However, the mice treated with anti-hCG did not litter; resorption of the embryos took place between Days 10 and 14 of pregnancy. Indirect immunofluorescence and quantitative immunoenzymic assays showed the presence of anti-ovine LH and anti-hCG reacting antigens in the mouse feto-placental unit. On Day 6, the values of reacting antigens (mean +/- s.d. absorbance units/10 micron section of embryo) were 0.050 +/- 0.002 with control globulins, 0.059 +/- 0.002 with anti-hCG-Ig and 0.196 +/- 0.018 with anti-LH-Ig; the corresponding values on Day 12 were 0.075 +/- 0.009, 0.402 +/- 0.02 and 0.416 +/- 0.015. The quantitative disposition of the reacting antigens to the two types of anti-gonadotrophins seems to bear a temporal relationship to their respective antifertility action. The pregnancy terminating action of immunoglobulins to ovine LH (Days 6, 7 & 8) and hCG (Days 8, 9 & 10) was counteracted by administration of 2 mg medroxyprogesterone acetate on Days 6, 9 and 12, indicating the importance of progesterone in the maintenance of pregnancy in the mouse.     

Effects of passive immunization against inhibin on ovulation rate and embryo recovery in holstein heifers

The effects of acute neutralization of endogenous inhibin on ovulation rate and circulating FSH levels were investigated. Nine or ten days after estrus, 5 heifers were given a single injection of 75 ml iv inhibin antiserum produced in a castrated male goat, while another 5 were given the same amount of a castrated male goat serum. All heifers were given injections of PGF2alpha im at 48 h and 60 h after the serum injection. Those exhibiting an estrus were artificially inseminated with frozen-thawed semen. Seven or eight days after the insemination, ova or embryos were collected using a non-surgical method. Administration of inhibin antiserum resulted in a significant increase in the number of medium-sized follicles compared with the number in the control animals. The number of large follicles in the inhibin-neutralized animals was 4.8 +/- 2.4 (mean +/- SEM; n = 5) on the day of estrus, while there was a single large follicles in the ovaries of control animals. Seven or eight days after estrus, 3 to 16 ova or embryos were recovered from 4 of 5 animals, and 64 % of the total ova/embryos were transferable. Administration of inhibin antiserum produced a significant increase in the concentrations of plasma FSH from 12 to 72 h after the serum injection compared with the levels in the control animals (P < 0.05). After the onset of estrus, preovulatory LH and FSH surges were noted in inhibin-neutralized animals and magnitude of the rise in each hormone was similar to the control animals. The present study demonstrates that a single injection of the inhibin antiserum induces multiple ovulations probably by enhancing FSH secretion, and that recovery of embryos is equal to that observation after an ordinary FSH treatment.     

Effect of lysophosphatidic acid on the ovum transport in mouse oviducts.

The effects of lysophosphatidic acid (LPA) on ovum transport in mouse oviducts were studied. When excised oviducts were incubated at 37 degrees C under 5% CO2 in humidified air for 24 hours, addition of LPA at 10 microM to the medium significantly accelerated the rate of ovum transport, and 1 microM LPA slightly increased the ovum transport rate. These increases were not inhibited by 10 microM indomethacin, a cyclooxygense inhibitor, but were suppressed by 260 ng/ml of pertussis toxin or 10 microM verapamil, a voltage-sensitive calcium channel blocker. These data suggested that LPA stimulates mouse ovum transport by contracting oviductual smooth muscle via a voltage-sensitive calcium channel mediated by a pertussis toxin-sensitive G-protein-linked receptor.     

Effects of passive immunization against oestradiol-17 beta on some endocrine values of the male lamb

Passive immunization of male lambs against oestradiol-17 beta from 2 to 16 weeks of age significantly elevated androgen concentrations in plasma and depressed the median eminence content of dopamine. Removal of endogenous oestrogens had no significant effects on plasma FSH, LH or prolactin concentrations or on testicular growth and hypothalamic content of GnRH. These results suggest that endogenous oestrogens may indirectly suppress testicular androgen secretion by exerting a stimulatory influence on hypothalamic dopaminergic neurones, which in turn may inhibit GnRH secretion by the median eminence.     

Active and passive immunization against luteinizing hormone in pigs

Active immunization of four adult pigs with highly purified porcine luteinizing hormone (pLH)--using method of multiside intradermal injections--has been performed and resulted in the production of specific antibodies. Immunization caused prolongation of estrous cycle to 47-49 days in two gilts and to 26 days in the other ones. Obtained anti-pLH pig serum was administered intravenously to 40 day pregnant gilt during 5 days (10 ml of serum, twice daily). Blood plasma progesterone (P4) concentrations decreased significantly from 8-13 to 2-4 ng/ml after two days of infusion and remained at this level for the next 5 days. Administration of this anti-pLH pig serum to gilt in the luteal phase of the estrous cycle caused the inhibition P4 to undetectable amounts. The different results were found after the passive immunization of 40 day pregnant gilt with rabbit anti-pLH globulin preparation (5 days, equivalent to 3 ml of original undiluted serum, twice daily). Although after two days of infusion P4 concentration decreased, in the next days P4 level slowly increased to pretreatment concentrations. The data suggest the possibility of specific anti-pLH antibody production in pigs by using active immunization, and the repeated utilization of such obtained antiserum in the same species for the inhibition of corpus luteum (CL) function.     

Active and passive immunization of mice against larval Dirofilaria immitis

The objective of this study was to determine if Dirofilaria immitis larvae would survive in diffusion chambers implanted in dogs and mice and secondly to determine if mice could be immunized against infection with D. immitis. Dirofilaria immitis third-stage larvae (L3) survived and grew in diffusion chambers implanted in dogs and mice for at least 3 wk. BALB/c mice, which were repeatedly infected with live L3, showed resistance to challenge infections. Dead L3, with or without adjuvants elicited no protective immunity. A correlation was found between the degree of immune protection seen in mice and antibody levels to soluble larval antigen but not to antibody levels to surface antigens. A monoclonal antibody was prepared that reacted with the surface of D. immitis and Onchocerca lienalis L3, but not to the surfaces of other stages and species of various filarial worms. When this antibody was administered to mice prior to challenge no significant reduction in larval survival was observed.     

A model of ovum transport

A theoretical fluid dynamical model of ovum transport in the oviduct incorporating transport mechanisms due to ciliary activity, muscular activity and an applied pressure drop across the oviduct is developed. Theory suggests that the cilia provide the steady component of ovum transport whereas muscular activity results in highly oscillatory motion. If muscular activity is to provide transport in a pro-uterine direction, a coordinated sequence of muscular activity with a strong pro-uterine bias is needed. Changes in pressure are highest in the narrowest sections. The highly convoluted rugae may allow "leakback" around the ovum so relieving the pressure drop across the ovum in narrower sections of the oviduct.     

Effect of passive immunization against substance P in rats with hyperprolactinemia

Substance P, an undecapeptide isolated from gut and brain tissues, was reported to stimulate prolactin release. It was suggested that substance P may play a role in the control of prolactin secretion. In this investigation we studied the effects of the blockade of endogenous substance P by the administration of a specific anti-substance P serum on serum prolactin levels in rats in the evening of proestrus, in lactating rats after suckling, and in male rats with hyperprolactinemia induced by grafting 2 anterior pituitary glands under the kidney capsule. The injection of the anti-substance P serum was followed by a significant decrease of the prolactin surge induced by 30 min suckling in lactating rats, when the antiserum was administered 24 hr but not 5.30 hr earlier. Anti-substance P serum also induced a significant decrease in serum prolactin levels in pituitary grafted rats, but induced no change in the proestrous surge of prolactin and LH. These results show that substance P may be involved in the release of prolactin induced by suckling and that this peptide may have an intrapituitary role in the process of prolactin release. On the other hand, substance P does not seem to play a significant role in the proestrous peak of prolactin and LH.     

Effect of passive immunization against progesterone on its distribution in circulation and tissues of mice

Anti-progesterone monoclonal antibody, injected into mice 32 h after mating at a dose that blocks the establishment of pregnancy, produced a significant reduction in the concentration of progesterone in the ovary and uterus within 6 h after treatment. Uterine concentrations remained lower in treated compared with control animals for at least 24 h after injection. There was an associated transient increase in plasma LH and FSH concentrations, but there was no change in plasma prolactin values. The percentage of total progesterone in the circulation that was unbound was reduced after treatment, but the concentration of unbound progesterone was increased. Studies of antibody binding of steroid in the presence of uterine progesterone receptor protein showed that there was a stoichiometric relationship in the distribution of ligand between the two binders. The present findings suggest that the effects of passive immunization against progesterone are associated with perturbation of tissue concentrations of steroid in the target organ as a result of high antibody concentrations in the circulation.     

A random walk model of ovum transport

This paper discusses the random nature of ovum transport, and presents a Brownian Motion model of ovum transport in the ampulla and isthmus. A new explanation of the delay in transport at the ampullary-isthmic junction, based on widely differing diffusion coefficients for the ampulla and isthmus, is proposed.     

Active and passive immunization protects against lethal, extreme drug resistant-Acinetobacter baumannii infection

Extreme-drug-resistant (XDR) Acinetobacter baumannii is a rapidly emerging pathogen causing infections with unacceptably high mortality rates due to inadequate available treatment. New methods to prevent and treat such infections are a critical unmet medical need. To conduct a rational vaccine discovery program, OmpA was identified as the primary target of humoral immune response after intravenous infection by A. baumannii in mice. OmpA was >99% conserved at the amino acid level across clinical isolates harvested between 1951 and 2009 from cerebrospinal fluid, blood, lung, and wound infections, including carbapenem-resistant isolates, and was ≥89% conserved among other sequenced strains, but had minimal homology to the human proteome. Vaccination of diabetic mice with recombinant OmpA (rOmpA) with aluminum hydroxide adjuvant markedly improved survival and reduced tissue bacterial burden in mice infected intravenously. Vaccination induced high titers of anti-OmpA antibodies, the levels of which correlated with survival in mice. Passive transfer with immune sera recapitulated protection. Immune sera did not enhance complement-mediated killing but did enhance opsonophagocytic killing of A. baumannii. These results define active and passive immunization strategies to prevent and treat highly lethal, XDR A. baumannii infections.     

Effect of short term passive immunization of the cyclic ewe against estradiol-17β

Three groups of 4 ewes were passively immunised against estradiol 17β during days 2 through 7, 10 through 17 and 15 through 20 of the estrous cycle respectively. The effects of the neutralisation of estradiol 17β at these specific times, on corpus luteum function, plasma concentrations of luteinising hormone (LH), estrus, and ovulation were observed.Passive immunisation at any phase of the oestrous cycle did not appear to effect the appearance of large ovarian follicles (5–15 mm diameter) at the next time of expected estrus, or the lifespan of the corpus luteum of that cycle. Treatment from day 15 to 20 of the cycle appeared to inhibit estral activity, ovulation and the preovulatory LH surge. Treatment from day 10 to 17 was less disruptive although some extension of the length of the estrous cycle was indicated, and treatment from day 2 to 7 produced little interference with cyclic reproductive activity.