Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.4.1 (myosin ATPase)
 1,140 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of amiodarone on heart weight, production of 14C-CO2 from labelled glucose, myosin ATPase activity, and myosin isoenzyme patterns were determined by comparing control and amiodarone-treated male Wistar rats. Since it has been suggested that amiodarone may interfere with thyroid hormone action on the heart, similar experiments were also carried out in hypothyroid and amiodarone-plus-triiodothyronine(T3)-treated rats, and the data were compared to those obtained in amiodarone-treated rats. Amiodarone treatment for 6 weeks resulted in lower heart weight, decreased atrial production of 14C-CO2 from labelled glucose, decreased myosin Ca-ATPase activity, and preferential synthesis of V3 isomyosin. These effects were similar to those observed in hypothyroid rats but were lesser in magnitude. T3 treatment of amiodarone-treated rats reversed all the changes induced by amiodarone. Serum thyroxine (T4) was higher in amiodarone-treated than in control rats, while serum T3 was similar. Serum T3 was higher in the amiodarone-plus-T3 than in the amiodarone-treated group. These results show that 1) amiodarone-induced changes resemble hypothyroidism with respect to cardiac myosin expression and atrial CO2 production, 2) amiodarone causes hypothyroid-like changes despite normal serum T3 and increased serum T4, and 3) T3 reverses the effects of amiodarone. These data support the hypothesis that amiodarone inhibits the action of thyroid hormone on the heart.
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PMID:Effect of amiodarone on rat heart myosin isoenzymes. 295 16

The effects of oxygenation (95% O2 + 5% CO2) and/or SOD (400 mg/l) on addition to St. Thomas' Hospital cardioplegic solution were examined by hemodynamic, cytochemical and biophysical assessments in the isolated working rat heart subjected to hypothermic ischemic arrest (22 degrees C in temperature, 180 min in ischemic time) with multidose cardioplegic infusion. According to the feature of used cardioplegic solution, thirty-two rats were divided into four groups (8 animals per group): That is, Group I; O2 (+) SOD (+), Group II; O2 (-) SOD (+), Group III; O2 (+) SOD (-), Group IV (control); O2 (-), SOD (-). Aortic flow (AF) recovery, expressed as a percent of pre-arrest AF, was 76.7 +/- 11.7% in Group I, 66.9 +/- 7.1% in Group II, 73.9 +/- 11.6% in Group III and 57.7 +/- 12.9% in Group IV (mean +/- SD). Differences in recovery between Group I vs III and Group III vs IV approached statistically significance (respectively, p < 0.01, p < 0.05). The birefringence ratio (ATP value/air value) of the biopsy specimen was 2.49 +/- 0.53 in Group I, 1.96 +/- 0.44 in Group II, 2.04 +/- 0.29 in Group III and 1.65 +/- 0.39 in Group IV (mean +/- SD). Difference between Group I and Group IV indicated statistically significance (p < 0.05). The birefringence ratio (X) had good correlation with the AF recovery ratio (Y): Y = 29.7 + 19.1X (R = 0.74). No statistical difference was seen from cytochemical assessment (myosin ATPase stain) in four groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Effects of oxygenation and/or SOD on addition to St. Thomas' Hospital cardioplegic solution]. 847 61