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Effects of calmodulin and protein kinase C antagonists on muscle in the filariid, Acanthocheilonema viteae.
- Source :
-
The Journal of parasitology [J Parasitol] 1995 Dec; Vol. 81 (6), pp. 989-96. - Publication Year :
- 1995
-
Abstract
- Drugs that act on calmodulin and protein kinase C (PKC) were investigated in the filariid Acanthocheilonema viteae. The filariid was slit open longitudinally and attached to an isotonic muscle transducer in a warmed (37 C) chamber containing physiologic solution bubbled with 95% N2-5% CO2. The calmodulin inhibitors, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7), increased the spontaneous contractions of the parasite at low concentrations and induced a contraction followed by a flaccid paralysis at high concentrations. Trifluoperazine and W-7 also reduced the contractions from acetylcholine (ACh) and KCl in a concentration-dependent manner. The phorbol esters, phorbol 12-myristate 13-acetate and phorbol 12, 13-dibutyrate, which activate PKC, were either inactive or only weakly active at inducing contractions. Staurosporine (10(-6) M), a PKC inhibitor, enhanced and then blocked the spontaneous contractions of the filariid. Two other PKC inhibitors, H-7 (10(-4) M) and sphingosine (3 x 10(-5) M), induced much smaller increases in the spontaneous contractions and did not inhibit them. Staurosporine and sphingosine inhibited the ACh contractions; however, staurosporine only slightly reduced the maximal KCl contraction. These results support a role for calmodulin, but not for PKC, in filarial muscle contraction.
- Subjects :
- Acetylcholine pharmacology
Alkaloids pharmacology
Animals
Female
In Vitro Techniques
Muscle Contraction drug effects
Phorbols pharmacology
Potassium Chloride pharmacology
Sphingosine pharmacology
Staurosporine
Transducers
Calmodulin antagonists & inhibitors
Dipetalonema drug effects
Enzyme Inhibitors pharmacology
Muscles drug effects
Protein Kinase C antagonists & inhibitors
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3395
- Volume :
- 81
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- The Journal of parasitology
- Publication Type :
- Academic Journal
- Accession number :
- 8544077