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Query: UMLS:C0231807 (exertional dyspnea)
 3,402 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An attempt was made to determine the importance of neurohypophyseal hormones for the emission of semen in rabbits. Arginine-vasopressin was used in a lower dose than by previous investigators. An analogue, de-amino-oxytocin (ODA 914) was included. Besides these peptides, arginine-v asotocin, the antidiuretic hormone in birds, was also used. This substance has been shown to be present in the pineal gland of the human fetus and may have a physiological function in animals. Teaser doe rabbits were ovariectomized 4 weeks before being used. 3 days before the experiments they were given 60 mcg of estradiol benzoate in arachis oil by sc injection. These injections were repeated every 3rd day during the experiments. Males, in 4 groups, received 1 of the hormones or saline iv every 2nd day until 15 injections had been given. About 30 seconds after each injection, a teaser doe rabbit was introduced and a sample of semen collected. The latency period from the time of introduction to the 1st ejaculation was timed with a stopwatch. Volume of ejaculate was measured and spermatozoa counted. The peptides injected had no effect on ejaculate volume. However, in those injected with vasotocin some difference was noted (p less than .05). Latency time was similar in all. Variations between individuals in ejaculate characteristics approached variations in differently treated rabbits. The number of spermatozoa was significantly increased only by arginine-vasopressin (p less than .05) for the 1st ejaculate. This is thought to be due to a conditioned response with release of neurohypophyseal hormones. It is concluded that vasopressin is the neurohypophyseal hormone which stimulates the release of spermatozoa in rabbits. The release of oxytocin during coitus may have other functions affecting male fertility.
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PMID:Neurophpophysial hormones and the emission of semen in rabbits. 120 23

The experiments, using a total of 1833 Cashmere does, were conducted to examine the effects on fertility and fecundity of intravaginal treatment for control of ovulation, time of insemination by cervical and laparoscopic methods, semen processing in pellets and straws, and number of frozen-thawed motile spermatozoa. Adult does (greater than or equal to 2.5 years) that had previously kidded were inseminated into the cervix, and maiden (kid: 6-8 months; hogget: 18 months) and adult does were inseminated laparoscopically. The rates of pregnancy determined by ultrasonic scanning (75-80 days after insemination) for cervical (Experiment 1) and laparoscopic (Experiments 2 and 3) insemination were 39.1%, 63.6% and 52.1%. The number of motile spermatozoa did not affect fertility after cervical (80, 120 and 160 x 10(6) or laparoscopic (Experiment 2: 15, 30 and 60 x 10(6); Experiment 3:5, 10 and 20 x 10(6) insemination. The method of insemination or number of motile spermatozoa did not affect fecundity. With cervical insemination, fertility and fecundity improved with increasing depth of insemination into the reproductive tract. Intravaginal sponges containing fluorogestone acetate and controlled internal drug release (CIDR) devices containing progesterone were equally effective for control of ovulation when combined with an injection of pregnant mare's serum gonadotrophin (PMSG; 200 i.u.) before insemination. Fertility was higher when does were inseminated before than after ovulation. After laparoscopic insemination, results were similar for semen frozen as pellets and in straws, and for 3-, 6- and 24-fold pre-freezing dilution of semen. For kid, hogget and adult does in Experiment 3, pregnancy rates were 34.0%, 55.4% and 63.9% and rates of fecundity were 1.17, 1.22 and 1.27 fetuses/pregnant doe.
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PMID:Artificial insemination of Cashmere goats: effects on fertility and fecundity of intravaginal treatment, method and time of insemination, semen freezing process, number of motile spermatozoa and age of females. 214 13

The mouse, rat, hamster, and rabbit have had remarkable success in surviving in the wild, which attests to their high reproductive capability. In fact, Parkes refers to mice conceiving at each postpartum estrus having the potential for 13 litters per year. Paufler et al. used GnRH to repeatedly cause ovulation in 27 rabbits a few days after parturition, resulting in an average pregnancy rate of 71.5%, 7.0 young born, 5.8 young weaned, and 50 young per doe per year. All four species produce an excess of spermatozoa relative to the requirements for fertilization. The rabbit is suitable for semen collection, artificial insemination, and most of the techniques one might wish to model for reproductive studies in both males and females. A major limitation to reproduction in these species is that reproductive capacity fails long before the finite oocyte population formed prenatally is depleted. The uterus of the aged female appears to be the major cause of reproductive failure, as fertilized eggs replaced in such a uterus usually soon deteriorate. With in vitro techniques, much is still to be learned about harvesting, maturing and fertilizing oocytes and identifying those most likely to result in formation of a healthy neonate.
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PMID:Factors limiting reproductive efficiency in selected laboratory animals. 319 45

The presence of rabbit spermatozoa in the uterine horn of the doe over a 10-hr period induced an increase in the incorporation of leucine-14C and orotate-3H [from 230 +/- 50 to 520 +/- 32 and 146 +/- 41 to 432 +/- 40 (dpm 10(3) mg DNA; Mean +/- SEM)] into endometrial proteins and nucleic acids. The addition of actinomycin D or cyclohexamide significantly inhibited this process. The intraluminal administration of dibutyryl cyclic AMP (dbcAMP) (control group) induced an increase two times greater than that produced by spermatozoa. The increase in the incorporation of radioactive precursors into endometrial macromolecules induced by the spermatozoa is independent of the uterine carbonic anhydrase activation produced by this cell.
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PMID:Effect of rabbit spermatozoa on the incorporation of labeled precursors into endometrial macromolecules. 616 Aug 22

Spermatozoa were recovered from the uteri and oviducts of mated does between 0 and 14 h post coitum (p.c.). The proportion of spermatozoa binding IgG before and after treatment with normal rabbit serum was assessed by immunofluorescence microscopy. Most spermatozoa recovered from the oviduct and from the uterus < 3 h p.c. did not bind IgG, in contrast to those of the ejaculate which did, and those from the uterus 4--10 h p.c. which were already coated with IgG when recovered. Spermatozoa transferred at 2 h p.c. to a recipient doe did not bind IgG 4 h later although a 6 h sample of the donor's spermatozoa did so; only approximately 150 of these spermatozoa were needed for all fertilized eggs/doe, whereas 10(4)--10(5) ejaculated spermatozoa were required when similarly inseminated. We suggest that the small numbers of spermatozoa that do not coat with IgG and are first through the cervix are those which normally fertilize. Whether they are are separate population in the ejaculate is uncertain.
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PMID:Sperm populations in the female genital tract of the rabbit. 700 Oct 10

The cervices of 2 normally mated does at 1 h post coitum were examined for the presence of leucocytes and compared with the cervix of an unmated doe. Cervical leucocytosis (50 x 10(6) leucocytes) was demonstrated following mating with either of 2 bucks, but not in the unmated doe. Each of 16 does was single-mated with 2 bucks whose offspring could be distinguished clearly. The interval between first and second mating was 0, 0.5, 1 or 4 h. One buck produced 68 offspring, the other buck produced 37. Cervical leucocytosis did not impair the fertility of the second buck even if it was the inferior buck; so fertilizing spermatozoa may traverse the cervices, even through large numbers of leucocytes. The differences in fertility between spermatozoa from different bucks during competitive fertilization may reflect different capacitation times of these spermatozoa.
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PMID:Investigation of sperm-induced cervical leucocytosis by a double mating study in rabbits. 712 Jan 79

Physical characteristics of semen quality were studied over a 12 month period in 10 post pubertal, young male goats (7-19 months of age) maintained under the naturally prevailing climatic conditions characteristic of the South of England (latitude N 51 degrees 46'). Semen was collected fort-nightly using an artificial vagina and an ovariectomized, oestrogenized teaser doe. The physical appearance of the ejaculates varied from a yellow or whitish-yellow colour during September-December to a creamy-white colour during the remainder of the year. Ejaculate volume decreased from 0.96 +/- 0.06 ml in October to the minimum value of 0.39 +/- 0.03 ml in April and 0.38 +/- 0.02 ml in July, after which there was a sharp increase to the highest value, 1.04 +/- 0.05 ml, in September. Sperm cell concentration per ml was lowest (3.66 +/- 0.16 x 10(9)), during November and highest (6.56 +/- 0.29 x 10(9)) during May. However, the total sperm per ejaculate were highest during the September and lowest in December. The mass and individual motilities were higher during August-December than in the remainder of the year. The percentages of dead and morphologically abnormal spermatozoa were highest during May. The effect of the months and seasons of the year on all parameters of semen quality were significant (P < 0.01).
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PMID:Seasonal variations in the semen quality of young British goats. 868 Aug 44

The relationship between the number of motile sperms inseminated and fertility rate and litter size at birth in rabbits was investigated. A total of 651 artificial inseminations on multiparous rabbit does in different physiological states (lactating or not; sexually receptive or not) were inseminated with a number of motile cells/dose varying from about 1-20 x 10(6). The statistical model computed the following traits: maximum expected value (a), rate of approach to this value (b) and number of motile spermatozoa/dose needed to obtain threshold level (95% of the maximum). The physiological condition of the doe affected the reproductive performance. The sexual receptivity had significant effect during lactation: non-receptive does had the lowest fertility (a: 43.70%; P < 0.05) while no significant differences were found in non-lactating ones (73.80 vs. 89.11%). Also the rate of approach to this maximum was different: non-receptive does showed a higher dependence on spermatozoa number than receptive females (b: 0.69 and 0.58, respectively, in lactating and non-lactating does) and consequently more spermatozoa (13.1 and 11.1 x 10(6) motile/dose) were needed to reach the threshold value. The physiological state of the does did not affect litter size and only 4.1 x 10(6) of motile spermatozoa/dose are needed to reach the threshold value.
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PMID:Effect of number of motile sperms inseminated on reproductive performance of rabbit does. 1056 43

In male Tokara (Japanese native) goats, testis development and the onset of puberty were studied histologically and observing sexual behaviour. Testes weight increased from 36+/-5.4 (S.E.) g (n=5) at 3 months of age to 126+/-6.3 g (n=6) at 12 months. The degree of the testis development differed among kids at 3 months of age and only one of four had produced spermatozoa in the testis. Large number of spermatozoa were always present in seminiferous tubules and epididymal ducts from 4 months of age. The diameter of seminiferous tubules increased from 133+/-9.9 microm (n=4) at 3 months to 198+/-1.0 microm (n=3) at 6 months with little increase thereafter. Mounting and pelvic thrusts onto a teaser doe started at from 9 to 14 weeks of age. Ejaculated semen contained sperm with good motility for the first time from 17 weeks. The male Tokara goat reaches puberty at around 4 months of age but testis development continues to 12 months.
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PMID:Testis developments and puberty in the male Tokara (Japanese native) goat. 1107 74

The effect of management of the female stimulus during semen collection and its association with libido re-establishment and the semen characteristics of sexually mature goats was evaluated. Eight 2-yr-old bucks were individually subjected to 12 weekly trials in which one of the following three treatments was applied alternately. In treatment one, each male performed two ejaculations on an estrus-induced, restrained doe and semen was collected with an artificial vagina (AV). In treatment two, males were collected as in the former treatment, but a different doe served as the stimulus female for the second ejaculation. In treatment three, two restrained does were present while collecting each buck, allowing males to choose which female to mount and serve in each of the two collections. Number of mounts before first ejaculation and reaction times (period from introduction of the ram to the test arena to his first ejaculation) were similar among treatments (P > 0.05). A significant (P < 0.05) decrease was found for number of mounts performed before achieving the second ejaculation and for latency between ejaculations in the third treatment. No differences (P > 0.05) were found for semen volume (0.8+/-0.03, 1.0+/-0.03, and 0.9+/-0.02 mL) or sperm concentration (4.4+/-0.15, 4.6+/-0.13, and 4.4+/-0.86 spermatozoa/mL) among the three treatments or between the first and second collection. However, a trend to decrease volume and concentration was observed. It was concluded that the simultaneous presence of two females while bucks are collected reduced the number of mounts performed before the second ejaculation and the latency between ejaculations.
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PMID:Management of the female stimulus during semen collection and its association with libido re-establishment and semen characteristics of goats. 1207 32


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