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Biomedical subjects

C R Lake

Publications and source records attributed to C R Lake.

At least 181 records · Page 10Linked to original sources
PubMed1977

Renin-aldosterone profiling in hypertension.

Renin-aldosterone profiling was used to classify patients with hypertension: 243 patients with essential hypertension were classified by renin-urinary sodium indexing; 107 were reclassified by response to administration of furosemide and intravenous saline; 45 were further classified by response to a low-sodium diet. Arbitrary "normal ranges" were determined in 89, 32, and 38 volunteers, respectively. Patients with low-renin apparently do not have "high-volume" hypertension. Rather, they show a primary renal abnormality in renin secretion and become relatively deficient in angiotensin II and aldosterone when they are subjected to diuresis. They can maintain aldosterone secretion under normal conditions because their adrenal aldosterone receptor is supersensitive to angiotensin II. No evidence of abnormal sympathetic neural activity was found among the renin subgroups. Renin-aldosterone profiling in current clinical practice seems useful mainly in the detection of patients with curable forms of secondary hypertension. Aldosterone/renin ratios may be particularly helpful in diagnosis when obtained after a patient has undergone expansion or contraction of his extracellular fluid volume.

Aldosterone↗
PubMed1976

Galactorrhea-amenorrhea: psychological interaction with neuroendocrine function.

Further substantiation of the interaction between psychological disease and the onset of galactorrhea-amenorrhea is presented in women who underwent intensive psychometric and neuroendocrine evaluation prior to the use of the dopamine against 2-Br-alpha-ergocryptine (CB-154). Normalization of a previously distorted psychometric test profile in each woman was accompanied by a profound decline in prolactin and an unexpected alteration in the peripheral concentrations of norepinephrine and dopamine-beta-hydroxylase. Cesation of galactorrhea and resumption of menses were observed in each instance.

Adult↗
PubMed1976

Deficient sympathetic nervous response in familial dysautonomia.

Norepinephrine concentration and dopamine-beta-hydroxylase activity were measured in the plasma of 10 dysautonomic patients and 10 normal subjects while they were reclining, standing and exercising. While reclining, dysautonomic patients had normal norepinephrine concentrations and blood pressure, but after standing they did not have a normal increase in their levels of norepinephrine (P less than 0.005), dopamine-beta-hydroxylase (P less than 0.05) or plasma protein concentration (P less than 0.01); they became hypotensive. In reclining dysautonomic patients there appeared to be a correlation between blood pressure and plasma norepinephrine concentration. These data support the view that hypertension and hypotension in dysautonomia are related to the rate of norepinephrine release.

Adolescent↗
PubMed1976

Amantadine versus trihexyphenidyl in the treatment of neuroleptic-induced parkinsonism.

Amantadine is a putative dopaminergic compound known to be therapeutically effective in idiopathic and postencephalitic Parkinson's disease. In a double-blind placebo-controlled crossover study of 39 psychiatric inpatients, amantadine and trihexyphenidyl were equally effective in treating drug-induced parkinsonism, and amantadine produced fewer and less severe side effects. The authors suggest that amantadine is an effective alternative to atropine-like agents, with fewer implications for long-term risk of tardive dyskinesia.

Amantadine↗
PubMed1976

NIH conference. Dopamine- -hydroxylase. Basic and clinical studies.

Dopamine-beta-hydroxylase, the enzyme responsible for conversion of dopamine to norepinephrine, is released along with catecholamines from the adrenal medulla and from sympathetic nerve endings. The properties and mechanisms of the enzyme's action are discussed and its distribution described. Dopamine-beta-hydroxylase is a valuable indicator of exocytosis as a mechanism for neurotransmitter release. The enzyme is present in plasma, but its levels vary widely between individuals. This variation seems to be related more to genetic factors than to sympathetic nerve activity. Abnormally high or low plasma levels are associated with several diseases. However, the relation of these levels to disease pathogenesis rather than to genetic determinants is unclear. Levels of the enzyme are elevated in patients with pheochromocytoma and decline after removal of the tumor. Dopamine-beta-hydroxylase levels seem to be normal in hypertensive patients. Inhibition of dopamine-beta-hydroxylase provides a useful pharmacologic approach to evaluating the role of norepinephrine in psychiatric disorders.

Adolescent↗
PubMedDate not supplied

Menstrual cycle and ovarian hormone effects on plasma and platelet monoamine oxidase (MAO) and plasma dopamine-beta-hydroxylase (DBH) activities in the rhesus monkey.

Dopamine-B-hydroxylase (DBH) and monoamine oxidase (MAO) in plasma and platelets were studied in six female rhesus monkeys during three complete menstrual cycles. The same monoamine enzymes of seven bilaterally ovariectomized females were compared with a group of controls. A difference was found in platelet MAO between a mid-menstrual-cycle peak and a perimenstrual trough in these animals, while plasma MAO was unchanged. DBH showed an inverted cyclical variation to that demonstrated by platelet MAO. The ovariectomized females showed significant differences from the controls, confirming the effects of the ovarian sex steroid hormones on platelet MAO and plasma DBH. The variation in these peripheral enzymes may be reflective of changes in brain monoamine systems, which may play some role in the behavioral changes observed during the menstrual cycle in primates.

Animals↗