i would like to inject substance P intravenously in rats. i will use Substance P acetate salt hydrate from sigma-Aldrich. is it better to dissolve in water or saline. is it better to use intraperitoneal route.
Im not sure for what purposes are you going to inject it (that depends is it going to be IV or IP) but any way for IV it MUST be dissolved in saline. For IP there are other vehicles that can be used besides saline but i have never seen that someone uses water as solvent!
all best
i am sure you are right about water. solubility was mentioned in sigma-aldrich pamphlet to be in water. that's why I was asking about saline.
Well for some in vitro assays it can be dissolved in water perhaps.
Sigma will always report solubility in 'water', as opposed to other solvents (ethanol or DMSO). if it will dissolve in water, it will almost always dissolve in saline as well.
Nikola is absolutely right, you cannot inject water IV, or your rats could die. You should not inject water IP either -- always use saline, or you will hurt your rats and make your experiment uninterpretable!
Intravenous Administration of Substance P Attenuates Mechanical Allodynia Following Nerve Injury by Regulating Neuropathic Pain-Related Factors.