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1.
ASAIO J ; 42(5): M630-6, 1996.
Article in English | MEDLINE | ID: mdl-8944957

ABSTRACT

Six adult sheep and four newborn lambs (5 days old) were implanted with stimulator leads into the latissimus dorsi muscle and connected to a Myostim 7220 pacing system (Telectronics Pacing Systems, Inc., Englewood, CO). Electrical stimulation was started immediately after the operation. After 8 weeks of electrical stimulation, contractile force (CF) in adult sheep decreased to 76-81%, and to 78-82% in lambs. After 2 weeks' delay, CF in adults was 96-98%, and only 89-93% in lambs. After a 30 min intensive stress test, unconditioned control muscle lost 39% in lambs and 43% in adults. Muscle conditioned for 8 weeks lost 7-8% CF. However, after 2 weeks' delay, CF in adult muscle lost 33%, but only 12% in lambs. After cessation of electrical stimulation, the LDH-5 and LDH-1 + 2 fractions reverted to initial levels in adults, whereas in lambs, these levels continued to follow trends established during electrical stimulation. In both adults and lambs, the percent area occupied by the mitochondria increased during electrical stimulation by 6.9% in adults and 6.5% in lambs. After electrical stimulation cessation, the percent area in adults returned to baseline levels, whereas it continued to be elevated in lambs (3.3% vs 5.1%, respectively). The transformed muscle of the lamb did not revert to baseline levels after a delay period.


Subject(s)
Electric Stimulation Therapy , Muscle Development , Muscle, Skeletal/growth & development , Muscle, Skeletal/physiology , Adaptation, Physiological , Age Factors , Animals , Animals, Newborn , Cardiomyoplasty , Heart Failure/surgery , Humans , Isoenzymes , L-Lactate Dehydrogenase/metabolism , Mitochondria, Muscle/ultrastructure , Muscle Contraction/physiology , Muscle, Skeletal/anatomy & histology , Sheep
2.
ASAIO J ; 41(3): M499-507, 1995.
Article in English | MEDLINE | ID: mdl-8573855

ABSTRACT

Some patients with pre end-stage congestive heart disease do not receive a significant hemodynamic benefit from dynamic cardiomyoplasty because, during prolonged preoperative immobilization, their latissimus dorsi muscle (LDM) becomes extremely weak. It is the authors' hypothesis that the local administration of an anabolic steroid into an electrically stimulated LDM will produce a thicker and stronger muscle with significant resistance to fatigue. The electrical stimulation training protocol of sheep continued for 8 weeks. For localized anabolic steroid administration an osmotic pump was placed in a subcutaneous pocket and the catheter was introduced into the LDM. The contractile force of electrically stimulated and unstimulated control muscle was studied. Control data were calculated as 100% and all other data were corrected to control. After 4 weeks there was no decrease in contractile force. The change seen was from 88 to 100% with different preloads (10, 15, and 20 g/kg) and amplitudes of impulses (5 and 10 V). After 8 weeks, the LDM was more powerful than before electrical stimulation, with a change of 97-133%. Usually after 8 weeks of electrical stimulation alone, contractile force decreases to 70-75%. During a fatigue test (30 min, 100 bursts per minute, 10-25 Hz, ripple frequency, 10 V impulse amplitude) after 4 and 8 weeks of our protocol, the LDM lost only 12% of its initial force, whereas control muscle lost 40%. Thus local anabolic steroid administration makes the LDM stronger and more useful for cardiomyoplasty.


Subject(s)
Cardiomyoplasty/methods , Muscle Contraction/physiology , Muscle, Skeletal/physiology , Animals , Electric Stimulation Therapy , Evaluation Studies as Topic , Heart Failure/pathology , Heart Failure/physiopathology , Heart Failure/surgery , Humans , Muscle Contraction/drug effects , Muscle, Skeletal/drug effects , Muscle, Skeletal/pathology , Nandrolone/administration & dosage , Nandrolone/analogs & derivatives , Nandrolone Decanoate , Sheep , Time Factors
4.
Plant Physiol ; 46(2): 307-14, 1970 Aug.
Article in English | MEDLINE | ID: mdl-16657455

ABSTRACT

The effect of several carbamates and trichloroacetic acid on the biosynthesis of epicuticular lipids from leaves of pea (Pisum sativum) was tested by chemical and visual methods. The carbamates tested included S-(2,3-dichloroallyl) diisopropylthiocarbamate (diallate), N-(3-chlorophenyl) isopropylcarbamate (chloropropham), S-ethyl dipropylthiocarbamate, and 2-chloroallyl diethyldithiocarbamate. Diallate reduced epicuticular lipids by 50% when the plants were root-treated and by 80% when vapor-treated. These results were supported by scanning electron microscopy and carbon replica techniques with transmission electron microscopy. The ratio of wax lipid components in the diallate-treated plants remained unchanged, with the exception of the primary alcohols, which were reduced. Diallate appears to interfere with the biosynthesis of a precursor to the elongation-decarboxylation pathway of lipid synthesis. N-(3-Chlorophenyl)isopropylcarbamate had no significant effect on total amounts of extractable epicuticular lipids, nor did it alter the structure of the wax formation on the leaves. The scanning electron microscopy micrographs indicated that S-ethyl dipropylthiocarbamate significantly reduced wax formation on pea leaves. 2-Chloroallyl diethyldithiocarbamate altered the structure of the wax formations, but not the total amount of wax (scanning electron microscopy). Trichloroacetic acid had little effect on wax deposition compared to diallate or S-ethyl dipropylthiocarbamate (scanning electron microscopy). The implication of the effect of the carbamates on epicuticular lipids and penetration of subsequent topically applied chemicals is discussed.

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