Differences in Pregnenolone and Adenosine Triphosphate Syntheses Between Mitochondria from Follicles and Corpora Lutea of Porcine Ovaries
| العنوان: | Differences in Pregnenolone and Adenosine Triphosphate Syntheses Between Mitochondria from Follicles and Corpora Lutea of Porcine Ovaries |
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| المؤلفون: | Michael J. Dimino, Michael A. Neymark |
| المصدر: | Biology of Reproduction. 28:142-147 |
| بيانات النشر: | Oxford University Press (OUP), 1983. |
| سنة النشر: | 1983 |
| مصطلحات موضوعية: | endocrine system, medicine.medical_specialty, Swine, In Vitro Techniques, Carbohydrate metabolism, Luteal phase, Mitochondrion, chemistry.chemical_compound, Adenosine Triphosphate, Ovarian Follicle, Corpus Luteum, Internal medicine, Follicular phase, medicine, Animals, Carnitine, ATP synthase, biology, Ovary, Palmitoylcarnitine, Cell Biology, General Medicine, Isocitrate Dehydrogenase, Mitochondria, Endocrinology, Reproductive Medicine, chemistry, Biochemistry, Pregnenolone, biology.protein, Female, Acetylcarnitine, Adenosine triphosphate, medicine.drug |
| الوصف: | Mitochondria from intact follicles (4-7 mm) and corpora lutea of porcine ovaries were isolated and compared with respect to their abilities to utilize various oxidizable substrates to support ATP and pregnenolone syntheses. The oxidizable substrates studied were isocitrate, citrate, malate and succi.nate (Kreb’s cycle intermediates), acetyl carnitine and paimitoyl carnitine (representative short and long chain fatty acids, respectively) and pyruvate (an intermediate of glucose metabolism). While there is an overall higher rate of ATP synthesis by luteal mitochondria, the increase in the utilization of certain substrates is especially dramatic. Palmitoyl carnitine and acetyl carnitine support ATP synthesis almost fivefold better in luteal preparations than in follicular mitochondria (120 vs. 25 nmol/min per mg protein), while isocitrate and citrate are eight times better (240 vs. 30 nmol/min per mg protein). It appears that fatty acids are poorly utilized by follicular mitochondria to support ATP synthesis, but are good substrates in luteal mitochondria. The inability of follicular mitochondria to utilize isocitrate to support ATP synthesis is not due to a lack of isocitrate dehydrogenase activity, since the activities of both the NAD4-dependent and NADr-dependent forms in follicular mitochondria are not significantly different than the corresponding activities in luteal mitochondria. With follicular mitochondria there are no significant differences between the rates of pregnenolone synthesis supported by various substrates (approximately 40 pmol/min per mg protein). While the rates of pregnenolone synthesis by luteal mitochondria also do not differ significantly with the various oxidizable substrates, the rates by luteal mitochondria are fiveto tenfold higher than the corresponding rates by follicular mitochondria. In summary, these studies show that luteal mitochondria have a greater ability to utilize fatty acids and isocitrate and citrate than do follicular mitochondria. In addition, while the rate of ATP synthesis varies with the oxidizable substrate utilized, pregnenolone synthesis requires an oxidizable substrate but does not exhibit any preference. |
| تدمد: | 1529-7268 0006-3363 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6900c3aadd646c7886ac8425804ad4fbTest https://doi.org/10.1095/biolreprod28.1.142Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....6900c3aadd646c7886ac8425804ad4fb |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15297268 00063363 |
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