Acute stimulatory effects of an LH-RH agonist on the ovary in pseudopregnant rats.

Pseudopregnant rats were anaesthetized on day 5 of pseudopregnancy with pentobarbital and hypophysectomy or sham operation was performed. Polyethylene cannulas were inserted into one of the femoral arteries and utero-ovarian veins. Five-minute blood samples were collected from the ovary for 40 minutes.

Acute effects of cadmium on preovulatory serum FSH, LH, and prolactin levels and on ovulation and ovarian hormone secretion in estrous rats.

On the day of diestrus II CFY rats were given 5, 10, or 15 mg/kg cadmium chloride (CdCl2) or 1.0 mL/kg of 0.9% NaCl.

Synthesis of angiotensin II antagonists with variations in position 5.

Six angiotensin II antagonists containing cyclohexylglycine (Chg) or cyclopentylglycine (Cpg) in position 5 were synthesized by stepwise elongation in solution, using the pentafluorophenyl ester method. The influence of substitution on the inhibitory properties of the analogues was studied in four different bioassays. [Sar1,Chg5,Lac8]AII proved to be the most potent antagonist with low intrinsic activity in both the in vitro and in vivo tests.

Increase of progesterone production in human and rat luteal cells by beta-adrenergic stimulation.

The effects of the beta 2-adrenergic agonist hexoprenaline were studied on the progesterone production of rat and human corpora lutea and compared to hCG-induced hormone production. Human corpora lutea were obtained from healthy patients, rat corpora lutea were harvested on day 6 of pseudopregnancy. Corpora lutea were digested by trypsin and homogeneous luteal cell suspension (6 X 10(5) cells/ml) was incubated for 2 h.

Inhibition of progesterone secretion and decrease of ovarian blood flow by isoxazole in pregnant rats.

Pregnant rats were treated on day 11 of pregnancy with 0.62, 1.25, 2.

Stimulation of progesterone production by adrenocorticotropic hormone and prostaglandin E2 in rat luteal cells.

The effects of adrenocorticotropic hormone (ACTH), human chorionic gonadotropin (hCG) and prostaglandin E2 (PGE2) on the progesterone secretion of luteal cells from rats were studied. Corpora lutea were harvested on Day 6 of pseudopregnancy and digested by trypsin. Homogeneous suspensions of luteal cells were used for short-term incubation.

Direct effects of ACTH on the ovary.

We have summarized the data of our former experiments which clearly demonstrate that ACTH increases ovarian blood flow in various mammals. Furthermore, when the ovary is primed with gonadotropic hormones it stimulates secretion of 17 beta-oestradiol and progesterone.

Effects of oxytocin and vasopressin on the ovarian blood flow, progesterone and oestradiol-17 beta secretion in oestrous rats.

Oestrous rats were anaesthetized with pentobarbital, one of the femoral arteries and veins and one of the ovarian veins were cannulated, and a thin polyethylene cannula was fixed in the ovarian bursa. Five-min blood fractions were collected from the ovary for 50 min. Following the control fractions 15 mU of oxytocin, 15 mU of vasopressin or 50 microliter of 0.

Effect of local GABA administration on rat ovarian blood flow, and on progesterone and estradiol secretion.

The effect of gamma-aminobutyric acid (GABA)--superfused onto the surface of the ovary--on ovarian blood flow and on estradiol-17-beta (E2) and progesterone (P) secretion was studied in anaesthesized, pseudopregnant rats. GABA, 0.5 mumol per 50 microliter per animal, significantly reduced the blood pressure in the femoral artery, increased ovarian blood flow, enhanced the rate of E2 release and markedly decreased P secretion.

Study of the luteinizing hormone-induced increase of ovarian blood flow during the estrous cycle in the rat.

CYF rats were anesthetized on various days of the 4-day cycle and blood samples were collected at 5-min interals from the ovarian vein before and after i.v. administration of 5 micrograms/100 g BW of luteinizing hormone (LH).

Porcine follicular fluid treatment at proestrus diminishes the serum progesterone level of rats in early pregnancy.

Proestrous rats were treated with porcine follicular fluid (pFF) or porcine serum (pS) extract, afterwards they were put with males together. Next morning, the sperm positive females were considered as day 1 pregnant animals. On days 2, 8 and 14 of pregnancy serum progesterone level was determined by RIA.

Alteration in the reactivity of hamster cheek pouch arterioles to prostaglandin E2 and noradrenaline during pregnancy or sex steroid treatment.

Dioestrous and pregnant, or ovariectomized hamsters treated with sunflower oil, oestradiol or progesterone were anesthetized with pentobarbital and the arterioles of the cheek pouch membrane were prepared for microcirculatory study. Prostaglandin E2 (PGE2) or noradrenaline (NA) were topically applied and changes of the arteriolar diameter were measured on the screen of a closed-circuit television. PGE2 induced arteriolar dilatation in dioestrous or ovariectomized hamsters, but induced vasoconstriction in pregnant or in oestrogen-treated animals.

Increase of ovarian progesterone secretion by beta 2-adrenergic stimulation in oestrous rats.

Oestrous rats were anaesthetized with pentobarbital and one of the femoral arteries, femoral veins and utero-ovarian veins were cannulated. Five min blood fractions were collected from the ovary for 50 min. Following two control fractions fenoterol, noradrenaline, isoproterenol (0.

Enhancement of the sensitivity of hamster check pouch arterioles to beta-adrenergic stimulus during pregnancy.

The adrenergic beta stimulant fenoterol induced a dose-dependent vasodilatation of hamster cheek pouch arterioles. The response to fenoterol was significantly larger on day 14 of pregnancy than in metoestrous animals. Since the serum progesterone and 17 beta-oestradiol level were also elevated on day 14, a relationship was suggested between the enhancement of vascular sensitivity and sex-steroid hormone levels.

Antagonism by PGE2 of the vasoconstriction induced by PGF2 alpha in human ovary in vitro.

Human ovaries from adnexectomy were perfused via the ovarian artery with constant volume of Thyrode's solution. Perfusion pressure was recorded while doses of PGF2 alpha or PGF2 (2.5, 5 or 10 microgram/min) were infused for 10 min.

Ovarian venous outflow, progesterone and 17 beta-oestradiol secretion and peripheral blood level during pregnancy in the rat.

Blood was collected from the right ovarian vein on every third day of pregnancy in rats and the ovarian venous outflow and haematocrit were measured. Progesterone and 17 beta-oestradiol were determined by RIA from the ovarian venous and peripheral blood and the secretion rate of progesterone (ng/min) and 17 beta-oestradiol (pg/min) was calculated. An elevated level of ovarian venous blood flow was found on day 9 and 12 of pregnancy when the progesterone secretion reached the highest values.

Study on the role of maternal sex steroid production and metabolism in the embryotoxicity of para-xylene.

CFY rats were exposed to inhalation of clean air or air containing para-xylene (3000 mg/m3) on the 10th, and 9th and 10th days of gestation. Uterine and ovarian venous blood flow, fetal weight, ovarian progesterone and 17 beta-oestradiol secretion, and the progesterone and 17 beta-oestradiol level of peripheral blood (uterine and femoral veins) were measured on the 11th day of gestation. Exposure to para-xylene decreased the weight of the fetuses and the progesterone and 17 beta-oestradiol levels of peripheral blood, but it did not influence the uterine and ovarian venous outflow and the ovarian progesterone and 17 beta-oestradiol secretion rate.

Effect of anti-rat-liver rabbit immune serum on the local circulatory reactions of the rat liver.

The effect of anti-rat-liver rabbit immune serum was studied on liver blood flow and on the reaction to vasoactive substances of the hepatic blood vessels. Male rats weighing 250 to 300 g were anaesthetized with pentobarbital. The femoral artery, the femoral vein and the portal vein were cannulated.

Inhibition of the stimulatory effect of ACTH on adrenal and ovarian blood flow by indomethacin in the dog.

In anoestrous dogs heated thermocouples were inserted into one of the adrenals and ovaries. The basal adrenal and ovarian blood flow was recorded and enhanced by 1.2, 2.

Stimulation of the alpha-and beta-adrenergic receptors in human ovarian vasculature in vitro.

The effect of fenoterol and norepinephrine was studied on the vascular resistance of in vitro perfused human ovary. It was found that the beta-adrenergic stimulant fenoterol causes vasodilatation, whereas the alpha-adrenergic stimulant norepinephrine elicits vasoconstriction in the arterial vascular bed of the ovary showing the role of adrenergic mechanism in the regulation of ovarian blood flow. It was supposed that therapeutical administration of beta-mimetic drugs leads to the elevation of ovarian blood flow, which may have special importance in the case of corpus luteum insufficiency.

Effects of prostaglandins on ovarian blood flow in the bitch.

Oestrus and anoestrous mongrel dogs were anaesthetized with chloralose-urethane. In one group, the ovaries were isolated in situ and the effects of a 15-min infusion of PGF-2alpha or PGE-2 on perfusion pressure were measured. In the other group, heated thermocouples were introduced into the stroma of each ovary to measure the changes of local blood flow in response to PGF-2 alpha and PGE-2 infused into the ovarian bursa for 15 min.