{'fraction_non_alphanumeric': 0.02593440122044241, 'fraction_numerical': 0.019832189168573607, 'mean_word_length': 5.833333333333333, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
CATABOLISM OF PROSTAGLANDIN ENDOPEROXIDES INTO PROSTAGLANDIN E2 AND F2x BY THE RAT BRAIN

Abstract— Tritium labeled prostaglandin (PG) endoperoxides PGG2 and PGH2 were rapidly transformed (2 min, 37°C) in good yield (> 50%) by homogenates of whole rat brain into a mixture of products including prostaglandin E2 and F2x: under similar conditions (10min. 37°C) tritium labeled arachidonic acid remained essentially unoxidised. The ratio of PGE‐like products: PGF2x formed was approx 0.5 as determined by radio thin layer chromatography. This ratio changed to unity when homogenates of cerebral cortex or cerebral hemispheres were employed. On the other hand cerebellar homogenates formed PGF2x in much greater amounts. The structures of the products were confirmed by mass spectrometry and were further supported by experiments using octadeuterio‐endoperoxides. In the latter experiments the resulting PGE2 and PGF2x contained the expected seven and eight deuterium atoms respectively. Evidence for the formation of heptadeuterio PGD2. heptadeuterio‐6‐keto‐PGF1, and hexadeuterio 12‐hydroxyheptadecatrienoic acid was also obtained by mass spectrometry. These experiments demonstrate for the first time in brain tissue the biosynthesis of labeled prostaglandins from exogenous tritiated and deuterated precursors.