Correlation between the malate dependent progesterone and citrate biosynthesis in the mitochondrial fraction of human term placenta. The stimulatory effect of ADP and ATP.
The relationship between malate dependent conversion of cholesterol to progesterone and citrate biosynthesis in human term placental mitochondria has been investigated. It has been shown that ADP and ATP (but not AMP) stimulate, significantly, both progesterone and citrate formation. The stimulatory effect of these adenine nucleotides was dependent on the presence of Mn2+ in the incubation medium. When Mn2+ was omitted or replaced by Mg2+ only negligible stimulatory effect of ADP and ATP was observed. Atractyloside and oligomycin were without effect on ADP and ATP stimulated progesterone and citrate production. Other dinucleotides tested as: GDP, UDP and CDP stimulated both progesterone and citrate formation only slightly. In all the experiments presented the rate of progesterone biosynthesis was found to be significantly correlated with the rate of citrate production. The experimental results presented in this paper suggest that the stimulatory effect of ADP and ATP on malate dependent progesterone biosynthesis is a consequence of an increased conversion of malate to tricarboxylic Krebs cycle intermediates. The possible mechanism by which ATP and ADP stimulate the citrate formation in human placental mitochondria is discussed.
J
J
Swierczynski
J
J
Klimek
L
L
Zelewski
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D001278:Atractyloside / Q000494:pharmacology; D002951:Citrates / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D008293:Malates / Q000502:physiology*; D008345:Manganese / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D009711:Nucleotides / Q000494:pharmacology; D009840:Oligomycins / Q000494:pharmacology; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000096:biosynthesis*
D002951:Citrates; D008293:Malates; D009711:Nucleotides; D009840:Oligomycins; D001278:Atractyloside; D000249:Adenosine Monophosphate; D008345:Manganese; D011374:Progesterone; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D008274:Magnesium