Sex differences in cardiac muscle responsiveness to Ca2+ and L-type Ca2+ channel modulation
| Autor: | Igor R Wendt, Claire L. Curl, Leanne Md Delbridge |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Male
medicine.medical_specialty Calcium Channels L-Type Contractility chemistry.chemical_compound Nifedipine Internal medicine Calcium flux medicine Extracellular Animals L-type calcium channel Rats Wistar Papillary muscle Pharmacology Sex Characteristics Myocardium Cardiac muscle 3-Pyridinecarboxylic acid 1 4-dihydro-2 6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)- Methyl ester Papillary Muscles Calcium Channel Blockers Myocardial Contraction Bay K8644 Rats Calcium Channel Agonists medicine.anatomical_structure Endocrinology chemistry Calcium Female medicine.drug |
| Zdroj: | European Journal of Pharmacology. 586:288-292 |
| ISSN: | 0014-2999 |
| Popis: | This study investigated sex-related differences in rat papillary muscle force generation in response to altered extracellular [Ca2+] ([Ca2+]o, 0.2 to 5.0 mM) and to L-type Ca2+ channel modulators (nifedipine and Bay K8644). At all [Ca2+]o examined, contractile force was significantly greater in male than female papillary muscles. The [Ca2+]o required for 50% maximum force was significantly lower in male [0.34 ± 0.06 mM] than female [0.61 ± 0.10 mM] papillary muscles. Nifedipine decreased contractile force in papillary muscles of both sexes in a concentration-dependent manner, but the extent of the contractile depression was more marked in male papillary muscles at all nifedipine concentrations examined. BayK 8644 produced a concentration-dependent increase in contractile force in male papillary muscles but notably, not in female papillary muscles. These findings show that sex differences in myocardial mechanical function are associated with sex-specific modulation of L-type Ca2+ channel responsiveness. Thus, the L-type Ca2+ channel could represent an important cellular locus from which sex-based differences in myocardial excitation–contraction coupling arise. |
| Databáze: | OpenAIRE |
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