Variations in circulating catecholamines fail to alter human platelet alpha-2-adrenergic receptor number or affinity for [3H]yohimbine or [3H]dihydroergocryptine.

A series of studies were performed to determine the relationship between physiologic levels of circulating plasma norepinephrine and epinephrine and human platelet alpha-2 binding site number and the affinity (KD) of these sites for antagonist radioligands. In one study, alpha-2-adrenergic binding site number and affinity were compared using both [3H]yohimbine and [3H]dihydroergocryptine as radioligands. There was good absolute and relative comparison for binding site number, but only a relative relationship for KD.

Inhalation and intravenous studies of UF6/UO2F2 in dogs.

Nineteen UF6/UO2F2 inhalation studies were undertaken in purebred, female beagle dogs (N = 16) to examine inter alia, (a) the possible relations of exposure, whole body, lung and renal uranium levels to excretion rates; (b) the threshold U6+ dose and renal concentration for renal injury; (c) the distribution and retention functions for U6+ in major tissues; (d) biochemical indicators of renal injury; and (e) aspects of U-induced tolerance. Each of these issues was investigated in the context of the chemical toxicity of U6+ following brief exposures to 235UO2F2 in the presence or absence of HF (the decomposition products of 235UF6). Both gamma-(235U) and alpha-(234U) counting methods were applied.

Comparison of a colorimetric assay for glycosylated hemoglobin with ion-exchange chromatography.

Because levels of glycosylated hemoglobin (GHb) are increased in diabetes and reflect the previous metabolic control, clinicians and clinical investigators are finding increasing applications for measurements of GHb in diabetic patients. We report the characterization of a colorimetric assay procedure for GHb and compare its performance with that of a commonly used assay by ion-exchange chromatography. Although results of GHb determination by both methods correlate highly (r = 0.