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Biomedical subjects

J Marcó

Publications and source records attributed to J Marcó.

31 records · Page 2Linked to original sources
PubMed1981

[Experimental reflex ovulation].

The effect of mating on ovulation and follicular maturation along the ovarian cycles were studied in the rat. The number and size of follicles and the number of ovules in the Fallopian tube were estimated. When the copulation took place between 16 hour of the diestrus and 16 hour of the proestrus phase, a significant increase in the number of large follicles and total follicles was found on the other hand, between 10 hour of the proestrus and 10 hour of the estrus phase, the number of ovules, small follicles and total follicles increased significantly. Thus, the copulation appeared to facilitate the follicular development and ovulation.

Animals↗
PubMed1981

[Effect of copulation on the follicular development and ovulation in rat (author's transl)].

The follicular development, ovulation and position of the oocytes in the stretched tubes at different phases and times of the rat's ovarian cycle, and the effect of different conditions of copulation on these processes have been studied. With copulation from the 16th hour of diestrus to the 16th hour of proestrus, the number of large follicles, follicles total, and oocytes plus follicles increased significantly. With copulation from the 10th hour of proestrus to the 10th hour of estrus, the number of oocytes, small follicles and follicles total increased significantly. Copulation, therefore, facilitates the processes of follicular development and ovulation.

Animals↗
PubMed1981

[Effect of copulatory behavior at different periods of the ovarian cycle on ovulation and reproduction in the rat].

The effect of copulation on ovulation and reproduction during the diestrus, proestrus or estrus phases was compared by evaluating insemination, fertilization, number of embryos and ovulation. Copulation increases both ovulation and number of embryos per rat. This increase was significant when copulation occurred during the late of proestrus phase, mainly after the 16 hours of the proestrus phase. The copulation effect was lower during the late hours of diestrus and during the whole estrus phase.

Animals↗
PubMed1981

[Effect of ethanol on ovulation, reproduction and fetal development in the rat].

Single doses of ethanol (0.5 and 4 g/kg) were injected at 18 h of the diestrus, 9 h of the proestrus and 18 h of the estrus phase (first day of pregnancy). The ovarian cycle number of ovules and ovarian follicles, insemination, number of embryos, fetal development and the observed malformation were evaluated. Alcohol (4 g/kg) at 18 h of the diestrus, increased the receptive estrus phase and the number of mature follicles in the ovary, while it decreased the number of ovulations, pregnancies and embryos in rats. It was found that alcohol (4 g/kg) at preovulatory periods, increased the percentage of dead and malformed fetuses, and decreased the length of the higher limbs. Furthermore, the same doses of alcohol administered at the first day of pregnancy, produced a decrease in weight, size and length of the legs. Results showed that single doses of alcohol injected in preovulatory periods and first day of pregnancy, had a teratogenic action. Furthermore, alcohol inhibited ovulation and stimulated animal receptibility when administered at 18 h of diestrus.

Abnormalities, Drug-Induced↗
PubMed1979

[Modification of the ovarian cycle, ovulation and reproduction in rat by administration of p-chlorophenylalanine in the pre and post ovulation period (author's transl)].

The effect of p-Chlorophenylalanine (PCPA) administered in pre and post-ovulation phases on ovulation reproduction and ovarian cycle was studied in rats. Vaginal smears, number of ovules, mature follicles and ovaric histologic features were evaluated. PCPA administered in the periods after follicular rupture prolongs the diestrus phase from 2 to 10 consecutive days and totally inhibits the reproductive conduct. When administered in the periods just prior to follicular rupture, PCPA prolongs the estrus phase from 2 to 4 consecutive days and does not totally inhibit reproduction. A progressive increase in reproduction took place as treatment time approached ovulation, to such an extent that the number of inseminated and fertilized rats when treated at the ninth hour of the proestrus phase, was superior to the control group. PCPA administered in periods after and before follicular rupture totally inhibits ovulation in all cases. Ovaries present many mature follicles, as many as in the controls sacrificed at the 18 hour of the proestrus, just before ovulation.

Animals↗
PubMed1979

[Supression by copulation of the inhibitory effect of p-chlorophenylalanine on rat ovulation (author's transl)].

The effect of copulating on reflex ovulation was studied in rat. The effect of PCPA (300 mg/kg, i.p.) on ovulation and reproduction was compared by evaluating number of oocytes in tubes, histologic features of ovaries, vaginal cycle, insemination, fertilization and number of embryos per rat. PCPA, administered on 9th and 16th h of the estrus phase, totally inhibits ovulation, stimulates reproductive behaviour and prolongs the estrogenic phase. When the animals are kept in copulatory conditions for 16 or 46 hours, the inhibition induced in ovulation disappears to the extent that 60% of the rats become pregnant though the number of embryos is under that of the control group. The farther the treatment with PCPA within the same cycle in the ovulatory period, the greater the inhibitory effect on ovulation is and the lesser the neutralizing effect produced by reflexes related to copulation. Administration of PCPA at the 16 hour of the diestrus causes a greater increase in the average number of embryos-as compared to administration at the 9 hour. In periods longer than 48 hours before ovulation, the inhibition brought about by PCPA is not suppressed by copulatory conditions kept for 16 or 24 hours and is only neutralized if they are kept during a complete cycle. Those treated with PCPA in the diestrus phase and maintained in copulatory conditions for 46 hours, present a higher average of embryos than those maintained in similar conditions for 16 hours.

Animals↗
PubMed1978

[Reflex factors that modify the effect of p-chlorophenylalanine on ovulation and reproduction in rats (author's transl)].

The appearance of reflex ovulation in rats under the influence of the copulation, has been studied. Evaluation of insemination, fecundation, number of embryos, ovarian cycle and ovulation in several groups of rats treated with doses of p-CPA (300 mg/Kg, i.p.), have been made. The application of p-CPA 48 hours before the estrus phase, inhibits the ovulation. This increases significantly through copulation. Reproduction is totally inhibited by p-CPA in animals under copulation conditions during 24 hours of the estrus phase. The inhibition is desappears if placed under copulation conditions during a full cycle. Inseminated rats had a 33% decrease in number of embryos with respect to the control group. The application op-CPA 24 hours before the estrus phase does not produce any inhibition effect. The decrease observed in the number of embryos is non-significant. When p-CPA is applied, instead, 48 hours before the estrus phase, there is total inhibition of the reproductive conduct.

Animals↗
PubMed1976

[Serotoninergic mechanisms in ovarian cycle (author's transl)].

Influence of 5-HT on the rat follicle rupture mechanism was studied by the administration of p-clorophenyl-alanine (p-CPA) (300 mg/kg) at different stages of the ovarian cycle. The ovarian cycle of treated rats was subject of investigation, as well as the histology of tubes and ovaries. Administration of p-CPA at 10 hours of metestrus phase induces an inhibition of ovulation. Predominant diestrus phases in the ovarian cycle and luteinitation of ovaries suggested an increase in progesterone secretion probably owed to a correspondingly greater prolactine secretion. Adequate 5-HT levels in central structures proved to necessary for normal ovulation.

Animals↗
PubMed1976

[Effect of p-chlorophenylalanine on rat reproduction under different conditions of lighting (author's transl)].

Reproduction in female rats kept on artificial cycles of light/darkness, continuous lighting and continuous darkness, has been studied. Three weekly doses of p-chlorophenylalanine (p-CPA), 100 mg/kg, were given to half of the rats in each group during the two preconditioning months before copulation. An evaluation has been made of the insemination, fecundation, number of embryos, ovarian cycle and level of 5-HT in the hypothalamus. The administration of p-CPA had an inhibitory effect on the reproductive behavior, especially pronounced in rats kept under continuous lighting and under continuous darkness. The difference in 5-TH levels were greater among the groups kept on cycles of light/darkness without treatment and with p-CPA (0.05 greater than P greater than 0.01). The importance of 5-HT in the mechanisms of reproductive behavior is emphasized.

Animals↗
PubMed1975

[Effect of 6-hydroxydopamine intracerebrally injected on reproduction in rats (author's transl)].

The effect of 6-hydroxidopamine (6-OH-DA) --250 mug-- intracerebrally injected on rat ovulation has been studied. Administration of 6-OH-DA in the nucleus accumbens septi and its heigbhourhood, inhibited follicle rupture, causing ovarian cycles with leucocitary phases in nearly all cases. The ovaries present a deep lutteynitation. Administration of 6-OH-DA in the strio-hypothalamic tract gives rise to a estrogenic cycle and to a normal number of oocytes in the tubes. The study of the fibrillar degeneration leads us to assumption of a probable adrenergic connections of the nucleus accumbens septi with the lateral hypothalamic area, preoptic area and olfactory tubercule. The influence of the nucleus accumbens septi on the mechanisms of follicle rupture is stressed.

Animals↗
PubMed1975

[Effect of p-chlorophenylalanine on the reproduction of the rat (author's transl)].

The effect of p-chlorophenylalanie (p-CPA) --300 mg/kg-- on reproduction has been studied in the female rat. Groups of animals were injected with a dose of 300 mg/kg of p-CPA 48 hours before proper copulation conditions at different moments along the ovarian cycle. Presence of spermatozoa in the vaginal frotis was negative in treated rats; in the control groups however, positivity was found in variable proportions according to the phase of the ovarian cycle: 30 ad 90% in diestrus and proestrus respectively. Treated animals showed continuous diestrus phases and diffuse luteinitation of the ovary. The results may indicate that a decrease of cerebral 5-HT, caused by p-CPA, lessens the reproductive behaviour of the female rat through mechanisms depending probably on the liberation of gonadrotrophins.

Animals↗
PubMed1975

[Serotoninergic and adrenergic factors influencing the ovulation and reproduction in the rat].

The action of 5-hydroxytryptamine (5-HT) on ovulation and reproduction in female rats with unique or repeated treatments of p-chlorophenylalane (p-CPA) was studied under different conditions of illumination. Histological studies were carried out on the tube and ovaries, controls of the ovarian cycle and of inseminations produce by vaginal deposits. An evaluation has been made of the insemination, fecundation, number of embryos, ovarian cycle and in anothers series hypothalamic determinations of 5-HT were carried out. In one group of rats the effect of intracerebrally administration (n. accumbens septi) 6-hydroxydopamine (6-OH-DA) (250 mug) on ovulation was studied. The administration of a unique doses of p-CPA (300 mg/Kg) induces an inhibition of the reproductive cycle in all its phases and in all the rats. Which repeated doses (100 mg/Kg) reproduction was inhibited in rats maintained under continuous illumination and under continuous darkness. Ovulation studies revealed that follicle rupture, was inhibited with a unique dose of p-CPA (300 mg/Kg). The histological study showed, marked luteinitation of ovaries. The ovarian cycle after a unique dose of p-CPA showed continuous diestrus phases. The results may indicate that a decrease of cerebral 5-HT producing a hormonal change which leads to the disappearence of the oestrogenic phase, with consequent inhibition of rupture and decrease in receptivity of the female rat. The administration of 6-OH-DA in the n.accumbens septi inhibited follicle rupture giving rise to manifest lutteynitation. A further study on the degeneration of nerve fibres, suggests the posssibility of adrenergic influence in ovulation of septal structures.

Animals↗