Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Sexual dimorphism of the vomeronasal organ and the accessory olfactory bulb of the mandarin vole Microtus mandarinus and the reed vole M.fortis

100%

Tai F. D., Wang T. Z., Zhang Y. H., Sun R. Y.

Acta Theriologica

2004

tom 49

nr 1

Sexual dimorphisms of the vomeronasal organ (VNO) and the accessory olfactory bulb (AOB) of the mandarin vole Microtus mandarinus Milne-Edwards, 1871 and reed vole M. fortis Büchner, 1889 are reported for the first time in the present work. The thickness and length of the vomeronasal epithelium (VE) and the nuclear size of the receptor cells, the width and length of the granule cell zone, the width and length of the mitral cell zone, and the density of the mitral cells were surveyed. The thickness and length of the vomeronasal epithelium (VE), the length of the granule cell zone and the mitral cell zone, and the densities of mitral cells were significantly different between male and female reed voles. Male and female mandarin voles had no significant differences in any of these parameters. Polygamous reed voles had a greater degree of sexual dimorphism in VNO and AOB than did monogamous mandarin voles. The present results provide evidence to the hypothesis that the degree of sexual dimorphism may be related to the mating system.

Action potential clamp and mefloquine sensitivity of recombinant IKs' channels incorporating the V307L KCNQ1 mutation

88%

El Harchi A., Mcpate M. J., Zhang Y. H., Zhang H., Hancox J. C.

Journal of Physiology and Pharmacology

2010

tom 61

nr 2

The slow delayed rectifier potassium current, 'IKs', contributes to repolarisation of cardiac ventricular action potentials and thereby to the duration of the QT interval of the electrocardiogram. Mutations to IKs channel subunits occur in clinically significant cardiac repolarisation disorders. The short QT syndrome (SQTS) is associated with accelerated ventricular repolarisation and with an increased risk of arrhythmia and sudden death. The SQT2 variant of the SQTS has been linked to a gain-of-function amino-acid substitution (V307L) in the KCNQ1-encoded IKs channel -subunit. This study reports the first action potential (AP) voltage-clamp comparison between wild-type (WT) and V307L KCNQ1 (co-expressed with KCNE1 to recapitulate IKs) and identifies an effective pharmacological inhibitor of recombinant 'IKs' channels incorporating the V307L KCNQ1 mutation. Perforated-patch voltage-clamp recordings at 37°C of whole-cell current carried by co-expressed KCNQ1 and KCNE1 showed a marked (-36 mV) shift in half-maximal activation for V307L compared to WT KCNQ1; a significant slowing of current deactivation was also observed. Under AP clamp, peak repolarising current was significantly augmented for V307L KCNQ1 compared to WT KCNQ1 for both ventricular and atrial AP commands, consistent with an ability of the V307L mutation to increase repolarising IKs in both regions. The quinoline agent mefloquine inhibited WT KCNQ1+KCNE1 with an IC50 of 3.4 µM compared to 3.3 µM for V307L KCNQ1+KCNE1 (P >0.05). This establishes mefloquine as an effective inhibitor of recombinant 'IKs' channels incorporating this SQT2 KCNQ1 mutation.

Ograniczanie wyników

1 Acta Theriologica

1 Journal of Physiology and Pharmacology

2 Zhang Y. H.

1 El Harchi A.

1 Hancox J. C.

1 Mcpate M. J.

1 Sun R. Y.

1 Tai F. D.

1 Wang T. Z.

1 Zhang H.

1 2010

1 2004

Wyniki wyszukiwania

Sexual dimorphism of the vomeronasal organ and the accessory olfactory bulb of the mandarin vole Microtus mandarinus and the reed vole M.fortis

Action potential clamp and mefloquine sensitivity of recombinant IKs' channels incorporating the V307L KCNQ1 mutation