Showing papers by "Richard M. Weinshilboum published in 1977"
TL;DR: Noradrenergic neurons originating in the locus coeruleus may contribute to the control of intraparenchymal cerebral vessels and disturbance of this control may be important in the pathology of cerebral ischemia.
94 citations
TL;DR: There was no difference in the recovery of purified rat liver COMT added to homogenates of liver and kidney from Fischer 344 and Wistar-Furth animals, a finding that makes it less likely that the different levels of COMT activity were due to differences in levels of endogenous enzyme activators or inhibitors.
32 citations
TL;DR: A radioimmunoassay for human DBH was developed and results are compatible with the conclusion that the presence of the allele for low plasma enzymatic DBH results in a decrease in the quantity of DBH protein in human plasma.
Abstract: Inheritance plays an important role in the determination of human plasma dopamine-beta-hydroxylase (DBH) enzymatic activity. It has been demonstrated that an allele (d) for very low enzymatic plasma DBH is inherited as an autosomal recessive trait. A radioimmunoassay for human DBH was developed to test the hypothesis that the presence of this allele results in a decrease in plasma DBH protein levels. The mean immunoreactive DBH (IDBH) in blood from a randomly selected population of adolescents was 824+/-38 ng/ml (mean+/-SEM, n = 134). The correlation coefficient of enzymatic DBH with IDBH for this group of 134 adolescents was 0.84 (P < 0.001). Of these subjects, 3.7% had values of < 100 ng/ml and appeared to compose a separate subgroup analogous to the 3-4% of the population that is homozygous for the allele for low enzymatic activity. There was a significant sibling-sibling correlation of IDBH values in the 14 sibling pairs included among the 134 subjects studied (r = 0.60, P < 0.025). IDBH was also measured in blood from 56 subjects homozygous (dd) for the allele for low enzymatic DBH (enzymatic activity < 50 U/ml) and in blood of 80 first-degree relatives of homozygous probands. All but two dd subjects had IDBH levels of <100 ng/ml. Results of family studies were compatible with the autosomal recessive inheritance of an allele for IDBH levels of less than 100 ng/ml which segregates with the allele for very low enzymatic activity. Average IDBH in blood of 37 obligate heterozygotes as determined by family studies (Dd) was 599+/-53 ng/ml (mean +/- SEM), significantly lower than the IDBH values found in a randomly selected population (P < 0.005). These results are compatible with the conclusion that the presence of the allele for low plasma enzymatic DBH results in a decrease in the quantity of DBH protein in human plasma.
29 citations