Pharmacological properties of the T-type Ca2+ current of mouse spermatogenic cells.

نویسندگان

  • C Arnoult
  • M Villaz
  • H M Florman
چکیده

The effects of pharmacological agents on the T-type Ca2+ current were studied in dissociated spermatogenic cells from the mouse. Ca2+ currents were elicited by depolarization in 10 mM Ca2+ and recorded in the whole-cell configuration of the patch clamp technique. The T-type current was inhibited by the following compounds: PN200-110 (IC50 = 4 x 10(-8) M) > nifedipine (IC50 = 4 x 10(-7) M) > pimozide (IC50 = 4.6 x 10(-7) M) > mibefradil (IC50 = 5 x 10(-6) M) > Ni2+ (IC50 = 3.4 x 10(-5) M) > verapamil (IC50 = 7 x 10(-5) M) > amiloride (IC50 = 2.4 x 10(-4) M) > Cd2+ (IC50 = 2.8 x 10(-4) M). However, the agents differed in the reversibility and the use dependence of their effects. Currents recovered rapidly and completely after removal of Ni2+, Cd2+, amiloride, or mibefradil, whereas recovery from verapamil block was rapid but incomplete. In contrast, we observed little recovery after the removal of pimozide and of the dihydropyridines (PN200-110, nifedipine). Moreover, mibefradil and pimozide exhibit a strongly use-dependent inhibition of current that is due to selective interaction of these drugs with the open state and the inactivated state of the channel, respectively, rather than with the resting state. These properties of the spermatogenic T-type Ca2+ channel differ from those of somatic cell T channels and suggest a molecular diversity of low voltage-activated Ca2+ channels.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Voltage-operated Ca2+ channels and the acrosome reaction: which channels are present and what do they do?

Evidence from pharmacological studies suggests that induction of the acrosome reaction of mammalian spermatozoa by solubilized zona pellucida, and possibly by progesterone, is dependent upon Ca2+ influx through voltage-operated Ca2+ channels. Studies on Ca2+ accumulation and membrane potential in ligand-stimulated or artificially depolarized spermatozoa support such a conclusion. Electrophysiol...

متن کامل

125I-Labelled mapacalcine: a specific tool for a pharmacological approach to a receptor associated with a new calcium channel on mouse intestinal membranes.

Mapacalcine is a small protein (Mr=19041) composed of two homologous chains purified from the marine sponge Cliona vastifica. Recently, we demonstrated that it was able to specifically block a Ca2+ channel which could not be related to already described channels on mouse intestinal myocytes. This Ca2+ current was insensitive to the known peptidic and organic calcium channel blockers. Mapacalcin...

متن کامل

Evaluation of Chronotropic Properties of Mouse Embryonic Stem Cells-Derived Cardiomyocytes After Fibroblast Growth Factor Treatment

Purpose: We investigated the effect of (bFGF) (basic-Fibroblast Growth Factor) on the differentiation of divided cardiomyocytes from mouse embryonic stem cells (ES) and their pharmacological properties. Materials and Methods: The mouse embryonic stem cells (Royan B1) were cultured as 800 cells per 20µl of a hanging drop. After two days, ES cells in each drop aggregated to form embryoid bodies ...

متن کامل

P-10: Proliferative Activity of Adult Mouse Male Germ Cells Following Administration of Graded Doses of Nicotine

Background: Nicotine is considered as one of the most agents in cigarette smoking and has side effects on many organs and body systems such as reproductive tract. Nicotine can induce sub fertility or infertility both in males and females. The aim of this study was to evaluate the proliferative activity of adult mouse male germ cells following treatment with different doses of nicotine. Material...

متن کامل

P30: Effects of Hemin on Ca2+Influx in Neurons of C57BL/6 Mouse Brain

Excitotoxicity results in a significant increase in Ca2+ influx; essentially from open N-Methyl-D-aspartate receptors (NMDARs) channels that cause a secondary rise in the intracellular Ca2+ concentration. It is correlated with neuronal death induced by Ca2+ overload. Dysfunction of NMDARs is associated with excitotoxic neuronal death in neurodegenerative disorders. In this study, the effects of...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Molecular pharmacology

دوره 53 6  شماره 

صفحات  -

تاریخ انتشار 1998