PubMed Health⌕ Search

Biomedical subjects

H J Hollemans

Publications and source records attributed to H J Hollemans.

11 recordsLinked to original sources
PubMed1976

The effect of indomethacin on kidney function and plasma renin activity in man.

125Iothalamate and 131I-hippuran clearances, sodium excretion and plasma renin activity (PRA) before and during indomethacin administration in an oral dose of 3 x 50 mg/day were studied in volunteers with a normal or reduced kidney function, as well on non-sodium-restricted as on sodium-restricted diet. Indomethacin induced a temporary sodium and water retention and a decrease in glomerular filtration rate. It also lowered PRA. The latter phenomenon did not depend on sodium retention and was present within 2 h after an oral dose of 50 mg. The results may be explained by indomethacin-induced inhibition of prostaglandin synthesis.

Glomerular Filtration Rate↗
PubMed1976

Radioimmunoassay of vasopressin in unextracted plasma.

A radioimmunoassay (RIA) for arg8-vasopressin (AVP) in unextracted human plasma was based on a sensitive anti-AVP rabbit antiserum, inhibition of enzymatic damage to [125I]AVP and AVP, and the use of an individual plasma blank, to correct for interference of plasma factors with the RIA. Sensitivity was 0.4 pg of synthetic AVP detected, corresponding to 1.2 pg/ml of AVP in human plasma. Recovery of AVP added to pooled plasma was 94 +/- 9.3% (mean +/- S.D.) in the low range (AVP, 2.8 pg/ml added) and 106 +/- 11.7% in the high range (45.0 pg/ml added). In 26 healthy, ambulatory subjects on ad lib, water intake, plasma AVP concentration was 2.0 +/- 1.22 pg/ml in the supine position and in 28 healthy subjects, 6.2 +/- 4.3 pg/ml in the upright position. Water loading suppressed the plasma AVP concentration. Smoking caused increased plasma AVP in 3 subjects despite water loading.

Drinking↗
PubMed1975

Scatchard plot and heterogeneity in binding affinity of labeled and unlabeled ligand.

In saturation analysis the Scatchard plot is a generally accepted method for calculation of the affinity constant, K, and the molar concentration, q, of the binder. However, in a system where the K's for the labeled and unlabeled ligand are unequal, a nonlinear plot can be obtained from which incorrect values for K and q may be calculated. This paper mathematically explains how the plot may deviate and under which conditions there will be a maximum in the curve. When the binding sites are homogeneous, the coordinates of this maximum can be used to calculate K and q. A general mathematical expression is derived on the basis of which a linear curve can be constructed for calculation of q and K, which is valid even when affinity for the labeled and unlabeled ligand is not identical.

Kinetics↗