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Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 865 records · Page 48Linked to original sources
PubMed1970

Radioreceptor assay of adrenocorticotropic hormone: new approach to assay of polypeptide hormones in plasma.

Biologically active iodine-125-labeled adrenocorticotropic hormone (ACTH) binds specifically to ACTH receptors extracted from adrenals. Unlabeled ACTH at 1 picogram per milliliter significantly displaces labeled ACTH from these receptors. This system, which appears to be applicable to all polypeptide hormones, provides a rapid and sensitive method for measurements of biologically active ACTH in dilute whole plasma.

Adrenal Glands↗
PubMed1970

ACTH receptors in the adrenal: specific binding of ACTH-125I and its relation to adenyl cyclase.

Pure monoiodo ACTH-(125)I was prepared that was biologically active and free of unlabeled ACTH. Extracts of adrenal cortex that contained ACTH-sensitive adenyl cyclase, bound ACTH-(125)I; extracts that lacked the ACTH-sensitive cyclase did not bind ACTH-(125)I. Unlabeled ACTH inhibited the binding of ACTH-(125)I. Five ACTH derivatives which varied widely in biological activity were tested. All inhibited the binding of ACTH-(125)I in direct proportion to their biological activity. Albumin, insulin, and four unrelated iodinated hormones were inert. The addition of excess hormone or acetic acid produced rapid dissociation of bound ACTH-(125)I. This study demonstrates directly the binding of ACTH to its biologically significant site.

Adenylyl Cyclases↗
PubMed1970

Immunoassay of plasma vasopressin in man.

A radioimmunoassay for arginine vasopressin has been developed that is sensitive to the hormone at 1 pg/ml. When plasma was filtered on G-25 Sephadex, immunoreactivity was detected in three regions. Endogenous arginine vasopressin was the third and smallest of the peaks and was recovered just after the salt. By combining gel filtration with immunoassay, we have made precise measurements of arginine vasopressin in a few milliliters of plasma.

Adult↗
PubMed1969

Plasma insulin: fluctuations in the "big" insulin component in man after glucose and other stimuli.

Plasma was filtered on G50 Sephadex, and two components of circulating insulin, "little" insulin and "big" insulin, were measured by immunoassay. The former component is indistinguishable from insulin, whereas the latter more closely resembles proinsulin and the other insulin-like substances isolated from the pancreas. In thin normal subjects, the fraction of plasma insulin that was big insulin (per cent "big"). 15-30 min after oral glucose, was less than 5%; per cent big rose 2- to 8-fold over the next hour and by 90-120 min represented 5-29% of the plasma insulin. In young thin subjects with idiopathic glucose intolerance associated with normal concentrations of plasma insulin, an identical pattern of big insulin was observed. In thin subjects in whom elevations of per cent big at 90-120 min during the standard test were only modest, starvation for 48 hr before the glucose administration resulted in a more pronounced rise in the per cent big insulin. Early after glucose administration to obese and acromegalic subjects, the per cent big was higher than in thin subjects. The magnitude of the elevation was roughly correlated with elevations in the fasting plasma insulin concentration. By 90-120 min, the per cent big in obese and acromegalic patients was the same range as in the thin subjects. Intravenously administered arginine and tolbutamide in a small number of subjects yielded a response that was similar to oral glucose; the per cent big was low early after stimulation and increased with time. In two patients with islet cell carcinomas, the per cent big was in the same range as in normal subjects.

Acromegaly↗