Gap 27 (Synonyms: Ser-Arg-Pro-Thr-Glu-Lys-Thr-Ile-Phe-Ile-Ile )

Cell lines

Rat osteoclasts

Preparation method

The solubility of this peptide in sterile water is >10 mM. Stock solution should be splited and stored at -80°C for several months.

Reaction Conditions

500 μM, 48 hours

Applications

Heptanol-treated cells acted as positive controls for gap-junctional inhibition. A significant decrease could be seen in the number of both TRAP-positive mononuclear and multinucleated cells with Gap 27 compared to controls. The numbers of TRAP-positive mononuclear and multinucleated cells with both treatments were very similar. After the 48-hour incubation, survival of osteoclasts was clearly reduced in the groups where gap-junctional communication was blocked either by heptanol or Gap 27.

Animal models

Female Sprague-Dawley rats

Dosage form

300 μM, 45 min

Applications

The rats were prepared with closed cranial windows 24 h before the study. A 10-mm-diameter craniotomy was performed over the skull midline. The dura was removed carefully to keep the sagittal sinus intact. An 11-mm-diameter glass window outfitted with three ports was glued to the skull using cyanoacrylate. The skin overlying the window was sutured, and the animals were permitted to recover. On the day of study, three stainless steel screws were inserted into the skull, along the periphery of the cranial window, for electroencephalogram (EEG) recording. Cannulae were then connected to the three ports. The rats were subjected to one of two neuronal activation paradigms: SNS or bicuculline-induced seizure. Following the initial measurement of pial arteriolar diameter changes during SNS or during bicuculline exposure, baseline conditions were reestablished. After 20 min, a suffusion of gap-27 was initiated. Forty-five minutes later, the neural activation was repeated. Application of gap-27 peptide attenuated bicuculline-induced pial arteriolar dilation (by ~ 50%), without altering neuronal activation. A similar result was obtained with the SNS-associated pial arteriolar response, although the degree of reduction in the vasodilating response (~ 75%) was somewhat greater.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

References:

[1] Ilvesaro J, Tavi P, Tuukkanen J. Connexin-mimetic peptide Gap 27 decreases osteoclastic activity. BMC musculoskeletal disorders, 2001, 2(1): 10.

[2] Xu H L, Mao L, Ye S, et al. Astrocytes are a key conduit for upstream signaling of vasodilation during cerebral cortical neuronal activation in vivo. American Journal of Physiology-Heart and Circulatory Physiology, 2008, 294(2): H622-H632.