Lactate Concentrations in Pre-Ovulatory Follicles of Pro-Oestrous Rats Before and After Onset of Oocyte Maturation

Zeilmaker, G. H.; Verhamme, Camiel

doi:10.1530/acta.0.0860380

Cited by 13 publications

(12 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lactate was used in these studies since it is known to be present in the ovary as a component of follicular fluid. It appears to be involved directly in granulosa cell metabolism, its concentration increas¬ ing towards the time of ovulation (Zeilmaker & Verhamme, 1977), probably as a result of increas¬ ing gonadotrophin stimulation (Hillier, Purohit & Reichert, 1985). The present results suggest that its importance to granulosa metabolism may be confined to the follicle.…”

Section: Discussionmentioning

confidence: 54%

Catecholamines and ascorbic acid as stimulators of bovine ovarian oxytocin secretion

Lück¹,

Jungclas²

1987

Journal of Endocrinology

View full text Add to dashboard Cite

The effects of catecholamines and ascorbic acid on cultured bovine granulosa cells have been examined to assess their possible role in the initiation and maintenance of luteal oxytocin secretion. The actions of these agents have also been compared with the previously reported ability of follicular theca tissue to enhance oxytocin secretion. Using granulosa cells cultured in serum-supplemented medium, we observed a highly significant enhancement of oxytocin secretion in the presence of adrenaline and noradrenaline, particularly over the concentration range 1-10 mumol/l. This effect was accompanied by smaller and less consistent changes in progesterone secretion and did not involve any change in the time-course of oxytocin secretion. Acetylcholine was without effect. Ascorbic acid stimulated oxytocin secretion when used alone over a range of concentrations, but was also able to synergize with adrenaline. Lactic acid was ineffective. The stimulation of oxytocin secretion by adrenaline could be blocked by equimolar propranolol, but the stimulation of progesterone was not blocked. Propranolol had a variable effect on the ability of theca tissue to stimulate oxytocin secretion by granulosa cells but the results also suggested the presence of some beta-agonistic activity in the culture medium. We conclude, first, that catecholamines may be involved in the regulation of ovarian oxytocin secretion, secondly, that ascorbate may regulate oxytocin secretion through its involvement in the biosynthesis of oxytocin but also through interaction with catecholamines and, thirdly, that the stimulatory action of theca tissue probably does not involve the action of beta-agonists.

show abstract

Section: Discussionmentioning

confidence: 54%

Catecholamines and ascorbic acid as stimulators of bovine ovarian oxytocin secretion

Lück¹,

Jungclas²

1987

Journal of Endocrinology

View full text Add to dashboard Cite

show abstract

“…The ovary produces appreciable amounts of lactate, even during the early follicular phase [65]. As follicular size increases, lactate levels also increase [66], coinciding with the start of antrum formation and detectable estradiol-17β secretion [66,67].…”

Section: Discussionmentioning

confidence: 99%

Mitochondrial 3 beta-hydroxysteroid dehydrogenase (HSD) is essential for the synthesis of progesterone by corpora lutea: An hypothesis

Chapman

Polanco

Min

et al. 2005

Reprod Biol Endocrinol

View full text Add to dashboard Cite

In mouse ovaries, the enzyme 3 beta-hydroxysteroid dehydrogenase (HSD) is distributed between microsomes and mitochondria. Throughout the follicular phase of the estrous cycle, the HSD activity in microsomes is predominant; whereas, after LH stimulation, HSD activity during the luteal phase is highest in the mitochondria. The current study examined whether or not LH stimulation always results in an increase in mitochondrial HSD activity. This was accomplished by measuring the HSD activity in microsomal and mitochondrial fractions from ovaries of pregnant mice. These animals have two peaks of LH during gestation, and one peak of LH after parturition. It was found that mitochondrial HSD activity was highest after each peak of LH. It is proposed that mitochondrial HSD is essential for the synthesis of high levels of progesterone. The increase in HSD activity in mitochondria after LH stimulation occurs because: 1) LH initiates the simultaneous synthesis of HSD and the cholesterol side-chain cleavage enzyme (P450scc); and, 2) HSD and P450scc bind together to form a complex, which becomes inserted into the inner membrane of the mitochondria. High levels of progesterone are synthesized by mitochondrial HSD because: 1) the requisite NAD+ cofactor for progesterone synthesis is provided directly by the mitochondria, rather than indirectly via the rate limiting malate-aspartate shuttle; and, 2) the end-product inhibition of P450scc by pregnenolone is eliminated because pregnenolone is converted to progesterone.

show abstract

“…Mori et al (1977) have shown that progesterone is necessary for ovulation in the rat and cyclic AMP can alone induce ovulation in the rat ovary perfused in vitro, without the previous exposure to the gonadotropin surge (Brannstrom et al 1986). Follicular function is dependent on energy charge since, at low oxygen tensions, the rat oocyte does not resume meiosis (Zeilmaker & Verhamme 1974) suggested by the authors to be due to low levels of ATP. Also, there are evidence that follicular growth and steroidogenesis is dependent on the mitochondrial function since the exposure of LH to follicles increases follicular growth, mitochondrial density, as seen by morphological studies, and mitochondrial pregnenolone production, in a parallel fashion (Dimino et al 1979(Dimino et al , 1980.…”

Section: Discussionmentioning

confidence: 99%

“…A follicular LH exposure is known to induce an increase in cyclic AMP and steroidogenesis (Ahrin et al 1979), an increase in glycolysis as measured by an increase in lactate production in vivo and in vitro (Nilsson 1974, Lindner et al 1974, Zeilmaker & Verhamme 1977 as well as oocyte maturation (Tsafriri & Kraicer 1972, Hillensjo et al 1974) and follicular rupture. The current view is that all these processes may be related to an increase in cyclic AMP, but they seem to be operative in a parallel fashion so that, for example, steroidogenesis, glycolysis and hormone-mediated processes seems not to be interdependent phenomena.…”

Section: Discussionmentioning

confidence: 99%

“…Follicular growth and steroidogenesis is associated with an increase in energy consumption (Naumoff & Stevenson 1985). The centrally located oocyte in rats is oxygen dependent, since no germinal vesicle breakdown and hence no oocyte maturation was seen in vitro, in the absence of oxygen (Zeilmaker & Verhamme 1974). There are also several studies concerning Correspondence: Dr Mats Gafvels, Department of Physiology, University of Umei, S p o r 87 Umei, Sweden.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Oxygen dependency of preovulatory follicles from pregnant mare serum gonadotropin‐treated immature rats

Selstam

Gåfvels

1987

Acta Physiologica Scandinavica

View full text Add to dashboard Cite

The present study was initiated to test to what extent preovulatory follicles are dependent on oxygen supply for maintaining their response to luteinizing hormone (LH). Female rats of the Sprague-Dawley strain were injected with 6 IU of pregnant mare serum gonadotropin (PMSG) on their 26th day of life. For in vitro experiments rats were killed 48-52 h after PMSG injection. Preovulatory follicles were dissected free, pre-incubated for 30 min and then incubated for 3 h without or with luteinizing hormone (LH, 1 microgram ml-1 medium) under different oxygen tensions in the gas phase (100, 13, 6 and 0 kPa). After incubation the accumulation of progesterone, cyclic-3',5'-adenosine monophosphate (cyclic AMP) and lactic acid were measured in the incubation media. Follicular adenosine-5'-triphosphate (ATP) content was measured in vivo (48-60 h after PMSG injection) immediately after isolation as well as after the incubation. Follicles isolated in vivo, during and after the ovulatory endogenous gonadotropin surge showed a depression in follicular ATP levels compared with levels before, suggesting that gonadotropins stimulate the follicle on the expense of ATP levels during the course of the preovulatory day. During a step-wise decrease of oxygen tension in vitro the preovulatory follicle maintained its response to LH as measured by progesterone and cyclic AMP accumulation. The preovulatory follicle could apparently compensate by increasing glycolysis, as measured by an increase in lactic acid accumulation. Tissue ATP levels were during these conditions maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

Lactate Concentrations in Pre-Ovulatory Follicles of Pro-Oestrous Rats Before and After Onset of Oocyte Maturation

Cited by 13 publications

References 6 publications

Catecholamines and ascorbic acid as stimulators of bovine ovarian oxytocin secretion

Catecholamines and ascorbic acid as stimulators of bovine ovarian oxytocin secretion

Mitochondrial 3 beta-hydroxysteroid dehydrogenase (HSD) is essential for the synthesis of progesterone by corpora lutea: An hypothesis

Oxygen dependency of preovulatory follicles from pregnant mare serum gonadotropin‐treated immature rats

Contact Info

Product

Resources

About