The oestrous cycle and monoamine oxidase activity

Holzbauer, Margarethe; Youdim, Moussa B. H.

doi:10.1111/j.1476-5381.1973.tb08246.x

Cited by 127 publications

(38 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…MAO in placenta plays a great role in the maintenance of pregnancy, and the placenta of patients with complications such as toxemia, diabetes mellitus, and hydatidiform mole have a low MAO activity (Yoshimoto et al 1986a). It was reported that during the rat estrous cycle, MAO activity of brain, uterus and ovary is changed corresponding to the alteration of sex steroid concentration (Holzbauer and Youdin 1973;Yoshimoto et al 1986b). However, the details of MAO activity in rat organs, such as liver, uterus, fetal liver and placenta during pregnancy still remains to be clarified.…”

mentioning

confidence: 99%

Gossypol effects on monoamine oxidase(MAO) activity in several organs of term rats.

Kono¹,

Lin²,

Gu³

et al. 1991

Tohoku J. Exp. Med.

View full text Add to dashboard Cite

In order to study the effect of gossypol on the monoamine oxidase (MAO) activity in pregnant rat organs, 20 day pregnant rats were sacrificed, and MAO activity/0.02 g tissue of several organs and total MAO activity/organ, were determined. The control group (n-5) were injected with vehicle intramuscularly on the 17th, 18th and 19th day of pregnancy, and the gossypol treated group (n 4) were injected with gossypol acetic acid (GAA) (25 mg/kg of body weight) intramuscularly on the 17th, 18th and 19th day and were decapitated on the 20th day of pregnancy. Maternal liver, uterus, placenta, and fetal liver were collected and examined. In placenta, total MAO activity/organ was significantly (p <0.05) lower in the GAA treated group than that in the control group. However, in maternal liver, uterus and fetal liver, there was no significant difference in total MAO activity/organ between the two groups. There was no significant difference in MAO activity/0.02 g tissue (specific activity), weight of organ, protein weight/ organ and protein/g tissue between the two groups in maternal liver, uterus, placenta and fetal liver. These results suggest that, after intramuscular injection of GAA, total MAO activity/organ in the placenta of pregnant rats might decrease significantly.

show abstract

mentioning

confidence: 99%

Gossypol effects on monoamine oxidase(MAO) activity in several organs of term rats.

Kono¹,

Lin²,

Gu³

et al. 1991

Tohoku J. Exp. Med.

View full text Add to dashboard Cite

show abstract

“…A specific regulatory system may exist to control rat placental MAO. This would not be unique because hormonal regulation of MAO activity in several rat organs has been reported (Holtzbauer & Youdim, 1973). Koren, Pfeifer & Sulman (1965) reported a gradual increase of serotonin and a gradual decrease of MAO in human placenta during pregnancy.…”

mentioning

confidence: 99%

Monoamine oxidase in rat placenta, human placenta, and cultured choriocarcinoma

Chen¹,

Klein²,

Robinson³

1976

Reproduction

View full text Add to dashboard Cite

Summary. The (Edlow, Köhler & Robinson, 1972). Tissues were homogenized in 9 vols of 0-167 M-potassium chloride for 3 min in an Omni-Mixer (Ivan Sorvall, Inc., Newtown, Connecticut), and the enzyme activity in the homogenates was assayed.The assay for MAO was a modification of the method of Wurtman & Axelrod (1964). In a total volume of 500 pi, the incubation mixture contained 250 mM-potassium phosphate buffer, pH 7-4; 0-5 mM-[2-1+C]tryptamine bisuccinate, 0-0325 pCi; and 100 pi enzyme preparation. At the end of incubation at 37°C for 20 min, a 0-2 ml volume of 2 n-HCI was added to stop the reaction. Toluene (1 ml) was then added for extraction of the product. After centrifugation, 0-5 ml toluene extract was added to 10 ml scintillation fluid and the radioactivity was determined. The enzyme activities were expressed in units (nmol product/hour) per g wet wt, per mg protein, per placenta, or per rat, as indicated after correction for 83 % recovery. Protein was determined by the method of Lowry, Rosebrough, Farr

show abstract

“…We chose this particular regimen of treatment with exogenous steroids not specifically to mimic natural cyclic changes but to be able to compare our results with those of Holzbauer & Youdim (1973) (Youdim & Holzbauer, 1976). For instance, kynuramine metabolism was increased two-fold whereas 5-HT metabolism was unchanged with progesterone treatment.…”

Section: Discussionmentioning

confidence: 99%

“…1.4.3.4). In several tissues known to be under the influence of ovarian hormones (uterus, ovary, endometrium), MAO activity is affected by changes in endogenous steroid level during menstrual (Southgate, Grant, Pollard, Pryse-Davies & Sandler, 1968) and oestrous (Holzbauer & Youdim, 1973) cycles or by treatment with exogenous steroids (Collins, Pryse-Davies, Sandler & Southgate, 1970). The lung has a large capacity to metabolize 5-HT via the action of MAO but the effect of ovarian steroids on this activity has not been investigated.…”

Section: Introductionmentioning

confidence: 99%

Effects of oestrous cycle and exogenous ovarian steroids on 5‐hydroxytryptamine metabolism in rat lung.

Bakhle¹,

Ben-Harari²

1979

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. The metabolism of 5-hydroxytryptamine (5-HT) in homogenates of lung and in perfused isolated lungs, was measured, using [14C]5-HT, over the 4-day oestrous cycle in rats.2. In lung homogenates, 5-HT metabolism (reflecting monoamine oxidase (MAO) activity) was greater during met-oestrus than during the rest of the cycle.3. In homogenates, the apparent Km for MAO activity was lowest during metoestrus whereas the, Vmax value was highest during di-oestrus.4. In perfused lungs, 5-HT metabolism and uptake was greater during pro-oestrus than during met-oestrus.5. In lung homogenates prepared from female rats treated with 17fl-oestradiol or progesterone for 8 days, the metabolism of 5-HT was increased.6. We conclude that although the lung is not usually considered a target organ for ovarian hormones, its metabolic activity is affected by changes in the levels of endogenous or exogenous ovarian steroids, an effect comparable with those already observed in uterus, ovary and other more commonly accepted target organs.

show abstract

The oestrous cycle and monoamine oxidase activity

Cited by 127 publications

References 26 publications

Gossypol effects on monoamine oxidase(MAO) activity in several organs of term rats.

Gossypol effects on monoamine oxidase(MAO) activity in several organs of term rats.

Monoamine oxidase in rat placenta, human placenta, and cultured choriocarcinoma

Effects of oestrous cycle and exogenous ovarian steroids on 5‐hydroxytryptamine metabolism in rat lung.

Contact Info

Product

Resources

About