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Biomedical subjects

L A Marjanen

Publications and source records attributed to L A Marjanen.

9 recordsLinked to original sources
PubMed1984

Calmodulin and malignant hyperpyrexia.

The function of calmodulin as a biological regulator is linked to the level of free Ca2+ in the cell, and there is evidence that calmodulin may itself be involved in the control of the movements of cellular Ca2+. Malignant hyperpyrexia, on the other hand, is caused by a disturbance in the level of myoplasmic Ca2+. We have investigated the possibility that calmodulin may be involved in malignant hyperpyrexia by studying the trifluoperazine-induced inhibition of calmodulin activation by phosphodiesterase, using crude and purified calmodulin preparations from control and MH-susceptible pigs. No abnormality was found in the pattern of either calmodulin activation or trifluoperazine-induced inhibition in MH muscle.

Animals↗
PubMed1983

Comparison of adenylate kinase from normal and malignant hyperpyrexic porcine muscle.

Adenylate kinase has been implicated as a key factor in malignant hyperpyrexia, a complication of general anaesthesia which is usually triggered by the anaesthetic drug, halothane. Because of this, the enzyme was purified from both malignant hyperpyrexia susceptible and control porcine muscle. Electrophoretic studies, amino acid analysis, and peptide mapping of the purified enzymes revealed no significant differences between the two preparations. Both enzymes responded similarly to halothane and to the three sulfhydryl reacting reagents which were tested and they also showed an identical affinity for the substrate AMP. It is concluded that porcine MH is not due to an abnormality in the enzyme AK.

Adenylate Kinase↗
PubMed1982

Effect of halothane on adenylate kinase in porcine malignant hyperpyrexia.

The effects of halothane on adenylate kinase activity in porcine muscle have been examined. No abnormality in malignant hyperpyrexia susceptible muscle was found. At clinical concentrations of halothane only slight inhibition of adenylate kinase activity was observed. The inhibition increased with increasing concentrations of halothane and with decreasing concentrations of the substrates AMP or ADP. The inhibition was similar in both malignant hyperpyrexia susceptible and control muscle. It seems unlikely that adenylate kinase is involved directly in triggering malignant hyperpyrexia.

Adenosine Monophosphate↗
PubMed1976

Isolation and partial charcterization of a cytochrome b complex and cytochrome oxidase from yeast mitochondria.

A cytochrome b complex and cytochrome oxidase have been purified 14- and 20-fold respectively from yeast submitochondrial particles by a simple procedure involving their spontaneous precipitation from a deoxycholate extract. The recovery of both proteins was almost quantitative. The specific heme contents were 11 and 8 nmoles/mg protein for the cytochrome b complex and cytochrome oxidase respectively and both were spectrally pure. Sodium dodecyl sulfate gel electrophoresis resolved the cytochrome b complex into seven distinct subunits with molecular weights 42,000, 33,000, 27,500, 23,000, 15,500, 13,000 and 10,500. Cytochrome oxidase contained five bands with molecular weights 42,000, 26,500, 21,000, 14,000 and 10,500.

Cytochromes↗