measurement concentration of drug in animals? help me

[konstantin]

the task is:
mice weigth - 30 gramm
chemical molecular wight - 100
how to make 10 micromol/kg?????

[blcr11]

30 g = 0.03 kg body weight

10 micromole of a 100 microgram/micromole compound is 1000 microgram.

You want to administer 1000 microgram (which is the weight of 10 micromole of compound) per kg of body weight or:

1000 microgram compound/kg body weight X 0.03 kg body weight = 30 microgram of compound.

[konstantin]

actually I do not understand what you said...
I need final concentration in mouse is 10 micromol/kg, and nothing more
I dont know how much I should take chemical and how much volume from this solution I should administer into mouse (if mouse weight is 30 gramm) .....

[blcr11]

The usual way to “dose” an animal is to administer so much substance per kg body weight. There is no such concentration as a “micromole/kg” like there is a mole/L. As I understand the problem, you need to administer 30 micrograms of a 100 MW compound to a 30 gm mouse to be giving a dose of 10 micromole/kg (of body weight of the mouse). Unless I’m missing something.

How much volume of stock solution you need to use to get 30 micrograms of compound depends on the concentration of the stock solution, not on the weight of the mouse. You will need to adjust the dose depending on the weight of the mouse—a little more if the mouse weighs more than 30 grams, or a little less if it weighs less than 30 grams. But it makes no sense to be talking about the “volume” of a mouse. (Well, technically you can estimate the blood volume and distribution space of the mouse, but that is only an estimate and I suspect beyond the scope of this problem unless your course is heavily into pharmacokinetics or pharmacodynamics.)

[konstantin]

ok I got it, thank you. actually I am get used to mg/kg rather than micromol/kg. may be i will keep this for further.