Lipase inhibitors abolish contractions and cause depolarization in frog skeletal muscle fibres.
Single, intact frog muscle fibers were exposed to bromophenylacylbromide (BPB) or nordihydroguairetic acid (NDGA). Fibres first became unable to respond to electrical stimulation and then depolarized; this process was accelerated by repeated activation. In addition BPB, but not NDGA, eventually induced a contracture in the fibre. The contractile response to direct Ca-release from the sarcoplasmic reticulum by caffeine was unaffected by the drugs.
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
J D
JD
Bruton
H
H
Westerblad
J
J
Lännergren
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D008049:Lipase / Q000037:antagonists & inhibitors*; D009637:Masoprocol / Q000494:pharmacology; D008564:Membrane Potentials; D009119:Muscle Contraction; D009132:Muscles / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D014982:Xenopus laevis
D000098:Acetophenones; D009637:Masoprocol; D008049:Lipase; C006821:4-bromophenacyl bromide