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Biomedical subjects

C Aron

Publications and source records attributed to C Aron.

At least 73 records · Page 4Linked to original sources
PubMed1982

Facilitory effects of male urine on feminine behavior in the male rat: androgen-dependency.

Feminine behavior in the male rat can be enhanced by exposing ORCH animals primed with estradiol benzoate and progesterone to the odor of urine collected from intact male adult congeners [20]. The present study provides evidence that this pheromonal effect is androgen dependent. A higher proportion of ORCH feminized rats displayed lordosis behavior following exposure to the odor of urine for either intact male rats or from ORCH rats supplemented with testosterone propionate than did ORCH feminized rats exposed to the odor of urine originating from non injected ORCH males.

Animals↗
PubMed1982

Influence of blood removal under ether anaesthesia on the release of prolactin during the oestrous cycle in the rat. Involvement of the ovaries.

The aim of this work was to study the stress-like effects of blood removal under ether anaesthesia at different stages of the di-oestrus period in 4-day cyclic female rats. Blood removal by heart puncture or laparotomy and bleeding from the abdominal vena cava both under ether anaesthesia were shown to precipitously evoked prolactin release on di-oestrus I morning and on di-oestrus II afternoon. Adrenalectomy did not prevent this effect from occurring on di-oestrus I morning following either procedure of blood removal. Ovariectomy completely suppressed the stress-like effects of ether anaesthesia whereas progesterone appeared capable of restoring prolactin release under these circumstances. No prolactin positive response to ether anaesthesia was observed on di-oestrus II morning, in unoperated control females.

Adrenalectomy↗
PubMed1982

[Effect of stress on the release of LH and FSH in female rat plasma. Critical study].

The aim of this work was to study the effects of different procedures of blood removal on blood LH and FSH concentration at different stages of the diestrous period in 4-day cyclic female rats. Cardiac puncture, abdominal cava venipuncture both under ether anaesthesia and trunk blood collection were performed on diestrus 1 morning and diestrus 2 morning and afternoon. Non operated, adrenalectomized, sham adrenalectomized cyclic females and ovariectomized females were used. No changes in blood LH and FSH concentrations were observed on either diestrus 1 or diestrus 2 in the non operated and adrenalectomized cyclic females and in ovariectomized females following blood removal by heart puncture and bleeding from the abdominal vena cava, both under ether anaesthesia, as compared to decapitated animals. By contrast, these two procedures of blood removal caused an increase in blood LH concentration in sham adrenalectomized females as compared to their decapitated counterparts. Only heart puncture evoked an augmentation of blood FSH concentration under this experimental schedule. In accordance with previous studies blood LH and FSH concentrations appeared to be greater in ovariectomized than in intact cyclic females.

Adrenalectomy↗
PubMed1981

[Action of estrogens on pituitary gonadotrophic function and follicular growth during diestrous in the rat (author's transl)].

LH and FSH release during the afternoon of diestrus 1 on the one hand, and the rate of follicular growth on the morning of diestrus 1 or diestrus 2, on the other hand, were studied in 4-day cyclic female rats after injection of estradiol benzoate (10 microgram, s.c.) on the morning of estrus. LH and FSH release was observed between 15.00 and 19.00 h during diestrus 1, but did not occur after an injection of pentobarbital (30 mg/kg, i.p.) in diestrus 1 at 13.30 h. No luteinization resulted from an injection of estrogen. Slowed follicular growth was observed on the morning of either diestrus 1 or diestrus 2. These results suggest the existence of a "critical period" for LH and FSH release in diestrus 1 during the afternoon. They indicate that the ovarian response to the endogenous release of gonadotropins is dependent upon the state of development of the ovarian follicles.

Animals↗
PubMed1981

Follicular growth, ovulatory phenomena and ventromedial nucleus lesions in the rat.

Small ventromedial nucleus lesions were placed in 4-day cyclic female rats in order to determine whether cycle lengthening - previously observed in some females following such lesions - could result from changes in follicular growth. A slowing up in follicle development was observed in lesioned females with a 24-hour cycle lengthening as compared to those with a maintained 4-day cyclicity. Similarly, natural 5-day cyclers displayed slower follicular growth than natural 4-day cyclers. A rebound effect in follicular growth was observed on proestrus in either natural or VMN lesioned 5-day cyclers compared to either natural or VMN lesioned 4-day cyclers. Concomitantly blood FSH level appeared to be higher on proestrus morning and afternoon in 5-day than in 4-day cyclers. The pattern of LH release differed between natural 4-day and natural 5-day cyclers on proestrus at 17:00-19:00 h. LH release appeared to be delayed by one hour in VMN lesioned rats with 24 hour cycle lengthening as compared to natural 5-day cyclers. The duration of LH release in VMN-lesioned rats with a maintained 4-day cyclicity was shorter than in natural 4-day cyclers.

Animals↗
PubMed1981

Involvement of the adrenals in ovulation induced by unilateral ovariectomy in the rat.

The aim of this study was to investigate the mechanisms of the stress-related ovulatory effects of unilateral ovariectomy (ULO) when performed on diestrus III at 10.00-11.00 hr in 5-day cyclic female rats. Ovulation evoked by ULO was suppressed in adrenalectomized rats. An increase in blood progesterone within 1 hour after ULO was observed in non adrenalectomized rats and suppressed in adrenalectomized rats. Pentobarbital (PB) treatment (30 mg/kg, ip) concomitant with ULO at 10.00-11.00 hr on diestrus III did not prevent progesterone to increase at 12.00-13.00 hr. A partial blockade of ovulation resulted from PB treatment from 13.00 hr to 18.00 hr on diestrus III. No blockade of ovulation occurred following PB injection at 23.00 hr. It was concluded that progesterone released from the adrenals following ULO constituted the trigger of ovulation during a critical period of diestrus III extending from 10.00 to 23.00 hr.

Adrenal Glands↗
PubMed1980

[Olfactory environment and heterotypical sexual behavior in the castrated male rat].

The display of heterotypical, that is feminine sexual behavior was studied in adult orchidectomized Rats treated with estradiol benzoate and progesterone following exposure to the odor of either male or female urine. The odor of male urine was shown to suppress an inhibitory influence of the olfactory bulbs on the heterotypical sexual behavior in the male Rat.

Animals↗
PubMed1980

Echographic study of follicular maturation and ovulation during the normal menstrual cycle.

Follicular development was followed by echography during 18 menstrual cycles in 10 women volunteers. Results were correlated with changes in serum hormone levels, basal body temperature curves, and cervical mucus changes. The average follicular growth as measured from the time of echographic visualization was 0.3 cm/day. The diameter of the follicle measured the day before disappearance was 2.7 +/- 0.3 cm. In all cases echography was shown to indicate accurately the time of ovulation. Given its inoffensive nature, the usefulness of echography in determining the physical event of ovulation is demonstrated. Possible applications in the surveillance of ovulation induction methods and in artificial insemination are discussed.

Adult↗
PubMed1980

Mechanisms of action of testosterone propionate on LH and FSH release by the pituitary gland in cyclic female rats.

The aim of this work was to determine whether changes in pituitary responsiveness to LRH could account for the effect of testosterone propionate (TP) on the gonadotrophic function of the pituitary in 4-day cyclic female rats. Doses of 250, 500 and 1000 ng LRH were injected ip on pro-oestrus at 15.30 h in rats either pre-treated with 5 mg TP on dioestrus II at 10.00 h or injected with 30 mg/kg pentobarbital (PB) at 13.00 h. LH release induced within 30 min by LRH was higher in PB than in TP-treated rats. Even by using 250 ng LRH full ovulation was observed on the morning of oestrus in PB-treated rats. On the other hand, only partial ovulation occurred whatever the dose of LRH used in TP-treated rats; a great number of luteinized follicles was shown to be constantly associated with post-ovulatory corpora lutea. While LRH caused a significant FSH release (30 min later) in TP-treated rats, no FSH release could be shown in PB-treated rats. The pituitary FSH content appeared to be decreased and the pituitary LH content remained unchanged while a sharp increase in both blood FSH and LH concentrations occurred following injection of 1000 ng LRH in TP-treated rats. Concomitantly a sharp decrease in the number of pituitary gonadotrophs (AB-PAS+) was observed. A significant decrease in the number of the small roundshaped PAS positive cells was also observed. The mechanisms whereby TP influences the function of the pituitary-ovarian axis are discussed in the light of these results.

Animals↗