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Biomedical subjects

J B Field

Publications and source records attributed to J B Field.

At least 181 records · Page 10Linked to original sources
PubMed1970

Catalase-dependent peroxidative metabolism in the alveolar macrophage during phagocytosis.

EVIDENCE FOR THE PRESENCE OF PEROXIDATIVE METABOLISM IN RABBIT ALVEOLAR MACROPHAGES (AM) HAS BEEN OBTAINED FROM THE FOLLOWING OBSERVATIONS: (a) catalase is present in high concentrations; (b) peroxidase activity could not be detected employing guaiacol as substrate; (c) the irreversible inhibition of AM catalase by aminotriazole served as a detection system for H(2)O(2) and demonstrated increased intracellular H(2)O(2) after phagocytosis; (d) formate oxidation, a marker of catalase-dependent peroxidations, occurs in resting AM and is increased by phagocytosis; (c) measurements of H(2)O(2) accumulation in a dialysate of AM demonstrated twofold increase during phagocytosis; and (f) aminotriazole diminishes O(2) utilization and (14)CO(2) production from labelled glucose and pyruvate. It is concluded that, while catalase-dependent H(2)O(2) metabolism is not essential for particle entry, this pathway represents one of the metabolic pathways stimulated by particle entry in the AM.

Animals↗
PubMed1969

Thyroid-stimulating hormone and prostaglandin E1 stimulation of cyclic 3',5'-adenosine monophosphate in thyroid slices.

Thyroid-stimulating hormone increased the cyclic 3',5'-adenosine monophosphate concentration in dog thyroid slices during a 1-minute incubation period and produced a maximum effect soon thereafter. The elevation persisted for at least 30 minutes. The concentrations of the cyclic 3',5'-adenosine monophosphate increased as the TSH concentration was increased from 0.125 to 50 milliunits per milliliter. Prostaglandin E(1), which increases glucose oxidation in dog thyroid slices, also increased the concentration of cyclic 3',5'-adenosine monophosphate. Although sodium fluoride stimulates thyroid adenyl cyclase, it did not increase concentration of cyclic 3',5'-adenosine monophosphate. Carbamylcholine and menadiol sodium diphosphate augment glucose oxidation in dog thyroid slices but do not change concentrations of cyclic 3',5'-adenosine monophosphate.

Adenine Nucleotides↗
PubMed1969

Stimulation of anterior pituitary adenyl cyclase activity and adenosine 3':5'-cyclic phosphate by hypothalamic extract and prostaglandin E1.

Hypothalamic extract, containing the releasing factors for anterior pituitary hormones, within minutes stimulated adenyl cyclase activity and adenosine 3':5'-cyclic phosphate (cyAMP) concentrations in rat anterior pituitary in vitro. Cerebral cortical extract was ineffective and hypothalamic extract had no effect on these parameters in posterior pituitary or thyroid. Prostaglandin E(1) also increased adenyl cyclase activity and cyAMP levels in anterior pituitary tissue. Although NaF augmented adenyl cyclase activity, it did not elevate cyAMP. Epinephrine, norepinephrine, histamine, serotonin, dopamine, and vasopressin did not increase either adenyl cyclase or cyAMP. The increased adenyl cyclase and cyAMP produced by hypothalamic extract was associated with greater luteinizing hormone release from anterior pituitary in vitro.

Adenylyl Cyclases↗