Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diurnal cycles in physical parameters in the environment modulate biochemical and physiological circadian rhythms in experimental animals, including cycles in the sensitivity to external influences. Environmental lighting synchronizes cycles of indole metabolism and melatonin synthesis in the rat pineal gland by modulating the activity of postganglionic sympathetic nerves. As a consequence, the sensitivity of pineal N-acetyltransferase to stimulation by isoproterenol or by dibutyryl cyclic AMP varies diurnally. Also, the capacity of actinomycin D to inhibit this induction varies with circadian periodicity. The cycles in sensitivity to isoproterenol reflect cycles in the system that regulates cyclic AMP production, and include variation in the availability of specific B-adrenergic binding sites, and in the sensitivity of receptor-coupled adenylate cyclase to catecholamines. Further, a variation in the response to dibutyryl cyclic AMP indicates in addition the participation of intracellular controls in the regulation of the sensitivity of N-acetyltransferase to catecholamines. The varying sensitivity to actinomycin D suggests a changing requirement for the synthesis of RNA as a function of prior environmental lighting conditions. The basic nature of these sensitivity changes suggests that diurnal cycles of environmental lighting may similarly affect other systems.
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PMID:Influence of diurnal cycles on biochemical parameters of drug sensitivity: the pineal gland as a model. 0 41

The correlative analysis of diurnal rhythms of cell number and adenylate cyclase cellular activity was performed in the thymus, spleen and peripheral blood of Swiss mice, intact or thymectomized at the age of 3 months. The existence of somehow synchronized diurnal rhythms of cAMP exchange and cell recirculation was found in the peripheral lymphocyte pool and in the thymus. Diurnal rhythm of cAMP synthesis in peripheral lymphocytes was regulated by the thymus. Thymectomy led to desynchronization of recirculating processes and cyclic nucleotide metabolism in immunocompetent cells.
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PMID:[Interrelation of diurnal rhythms of recirculation of lymphocytes and their synthesis of cAMP]. 301 80

Bromocriptine is an ergopeptine derivative and dopamine agonist that predominantly stimulates the striatal D2 non-adenyl cyclase-linked dopamine receptors. Bromocriptine, unlike other dopamine agonists, has mixed "agonist-antagonist" properties at these receptors. The striatal dopamine receptors exist in two different affinity states: a low and a high affinity state. Bromocriptine, unlike other dopamine agonists, does not differentiate between the low and the high affinity state of the D2 receptors, and bromocriptine does not induce a conformational change in these receptors. Bromocriptine, in low doses, is effective in patients with mild to moderate Parkinson's disease, while bromocriptine in higher doses is needed in patients with advanced disease. Both in low doses and in high doses, bromocriptine combined with levodopa is usually more effective than bromocriptine alone. The efficacy of low dose (5-30 mg/day) and high dose (31-100 mg/day) bromocriptine alone and with levodopa was examined in 27 studies encompassing 790 patients. Forty-six % of the studies were done in a double blind manner. In four studies of 79 patients, low dose bromocriptine (16 mg/day) without levodopa resulted in improvement in 58% of the patients. Only 9% of the patients experienced adverse effects. Most of the patients (63%) and mild or moderate Parkinson disease. In seven studies of 143 patients, high dose bromocriptine (56 mg/day) without levodopa resulted in improvement in 62% of patients, but with 27% having adverse effects. Most of these patients (77%) had mild or moderate disease. Diurnal oscillations in performance, the "wearing off" or "on-off" effect, were not seen during treatment with bromocriptine alone. In nine studies of 201 patients, low dose bromocriptine (23 mg/day) and levodopa resulted in improvement in 71% of patients with 26% having adverse effects. Most of these patients (66%) had advanced disease, and many had diurnal oscillations in performance. In seven studies of 367 patients, high dose bromocriptine (48 mg/day) and levodopa resulted in improvement in 58% with 37% having adverse effects. Most of these patients (85%) had advanced disease. The increased effectiveness of bromocriptine in combination with levodopa may be explained as follows. Bromocriptine by itself does not discriminate between the low and the high affinity states of the dopamine receptors.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Bromocriptine in Parkinson disease. 390 Oct 46