Identification of 7ξ-hydroxytetrahydrocortisol and 7ξ-hydroxytetrahydrocortsone from urine of newborn baboons (papio papio)

Two highly polar, unconjugated metabolttes of tetrahydrocortisol and tetrahydrocortisone, which had been shown previously to account for > 40% of [¹⁴C]cortisol (F) administered to baboon neonates, were isolated from urine of a term newborn animal. Metabolltes were extracted with ethyl acetate, purified by sequential paper chromatography and crystallization, and identified by chemical and biochemical procedures. Both metabolltes of F are 5β-pregnanes with a hydroxyl of unknown orientation at C-7, a 3α-hyd roxyl, and a dihydroxyacetone side chain. The two compounds differ from each other by the presence of et ther oxo or hydroxyl functions at C-11. The following nomenclature is proposed: unknown I; 3aα,7ξ,11β,17,21-pentahydroxy-5β-pregnan-20-one (7ξ-hydroxytetrahydrocortisol); unknown II: 3α,7ξ,17,21-tetrahydroxy-5β-pregnane-11, 20-dione (7ξ-hydroxytetrahydrocortisone). Production of these compounds compensates quantitatively for the decreased formation of F glucuronoside metabolites by baboon neonates, compared with that in adults. Therefore, we propose that 7-hydroxylation is a major alternative pathway for F metabolism in the perinatal period of the baboon.     

Abstracts of papers to be presented at the Tenth Annual Meeting of the American Society of Primatologists Madison,Wisconsin June 13–16, 1987

Invasive surgical procedures are often used to study the reproductive and adrenocortical endocrine systems in primates. Anesthetic agents must, therefore, be used that have the least confounding effects on these systems. The present study was designed to characterize various adrenocortical endocrine responses of female baboons (Papio anubis), each treated for 120 minutes with an infusion of ketamine HCl (6 mg/min) in 5% dextrose in water (0.40 ml/min), a combination of ketamine and acetylpromazine (0.6 mg acetylpromazine and 6 mg ketamine HCl/min) in 5% dextrose in water, or inhalation of vaporized halothane (1.0% halothane, N₂O 25%, 1 liter/min; O₂ 75%, 3 liters/min). Blood samples were collected throughout the treatment period, and serum was assayed for prolactin (PRL), dehydroepiandrosterone (DHA), dehydroepiandrosterone sulfate (DHAS), and cortisol (F). No significant elevations in DHA, F, or PRL concentrations were found following infusion of ketamine alone. Only serum DHAS concentrations were significantly altered after long-term exposure to ketamine. Acetylpromazine increased PRL concentrations tenfold to levels significantly greater than those in ketamine- and halothane-treated animals but had no effect on serum DHA, DHAS, or F. Treatment with halothane had no effect on serum PRL, DHA, or DHAS but did suppress F (>40%) concentrations over time. These data indicate that ketamine is best suited for the collection of biological samples when deep analgesia is not required but that halothane is preferable in the latter situation.     

THE MYOSIN FILAMENT : IV. Observation of the Internal Structural Arrangement

The subunit organization of the myosin filament of chicken striated muscle has been observed directly in cross-sections in electron microscopy. The organization consists of three centrally located and nine peripherally located subunits in a close-packed arrangement. This arrangement is that predicted by a previously derived model for the detailed molecular organization of the myosin filament (Pepe, 1966 a, 1967 a, 1971). Each subunit measures approximately 30 A in diameter and the center-to-center distance is approximately 37 A. If these measurements are considered to be on the high side, then they indicate that each subunit represents one myosin molecule. However, it is not possible to determine unequivocally whether one or two myosin molecules per subunit are present on the basis of this work.     

Protein synthetic activity in swimming sea urchin spermatozoa

Summary

Free swimming Paracentrotus lividus spermatozoa show a significant rate of protein synthesis which remains nearly linear over a period of 90 min. This protein synthetic activity is scarcely affected by emetine but completely suppressed by chloramphenicol, suggesting its possible mitochondrial origin.