It is difficult to pick a dose, although the discussion above will give you a range. This has been debated extensively elsewhere on RG. You can find the previous discussions in my answers under contributions on my RG page. Batches of STZ vary in potency, even from the same supplier and due to equilibration of enantiomeric forms the time from mixing to injection is important also. STZ is most stable in citrate ph4.5. Feeding status matters as STZ is taken up into beta cells by GLUT2 and glucose is therefore a competitive inhibitor for uptake. Strain matters and even the same strain will sometimes require a different dose in different colonies. We have always done an initial dose titration experiment with a given strain in our colony ensuring that all these variables are controlled. With this initial time invested you will find STZ induced diabetes a reliable reproducible model.

I think you have injected higher amount of STZ. Please check the amount what you have injected. I used to prefer IP to administrate the STZ.

Dear Shaymaa

I agree with you that IV is better than IP. But IP is easy to do. I think the half life of STZ is 40 mins. Within that time it will reach to the target (pancreas).

Hi Shymaa

No i haven't done so i would try out that also. I am using Ip

Hi Rajaram

I don't thk so its high dose, Papers indicate that IP is quite often used....

Hey you can look this link. Might be useful for you. https://www.researchgate.net/post/Erratic_Blood_Glucose_levels_in_STZ_treated_rats?ev=tp_feed_post_xview

65 mg/kg would kill the rats...use 45 mg/kg max...

Thanks Salih Sanlioglu..... I would try that out, how long does 45mg/kg retain sugar levels in rats.

Hi Shaymaa

Thanks for your comments. I'm using wistar rats. I am reducing my concentration now. I also have a doubt that once after induction of diabetes which method is best to draw blood either tail cut or from tail vein to check out the sugar levels.

Awaiting for response.....

Shaymaa

I jus need to follow up once a week for about 4weeks so that i can be sure that till 4 weeks it has been diabetic. I use glucometer, So just a drop of blood is enough.

I think you might find this paper quite useful.

Cell Transplant. 2001 Mar-Apr;10(2):145-51.

I used to use 55mg/kg IP in non-fasting subjects (0.9% NaCl as solvent, but you can also use citrate buffer). If you use fancy AccuCheck you should be able to use

Hey Arun,

As far as our experience we observed that SD rats are more prone to oxidative stress than Wistar rats, so 45mg/kg might not work. I dont now from which source you are buying STZ. Sigma STZ worked at 55 mg/kg perfectly but when once we tried from other source (as it was cheaper) we observed more death at same dose.

It is difficult to pick a dose, although the discussion above will give you a range. This has been debated extensively elsewhere on RG. You can find the previous discussions in my answers under contributions on my RG page. Batches of STZ vary in potency, even from the same supplier and due to equilibration of enantiomeric forms the time from mixing to injection is important also. STZ is most stable in citrate ph4.5. Feeding status matters as STZ is taken up into beta cells by GLUT2 and glucose is therefore a competitive inhibitor for uptake. Strain matters and even the same strain will sometimes require a different dose in different colonies. We have always done an initial dose titration experiment with a given strain in our colony ensuring that all these variables are controlled. With this initial time invested you will find STZ induced diabetes a reliable reproducible model.

For Wistar rats, you may want to check out the pub below. For Sprague Dawley use 40 mg/kg max....

Adenovirus-mediated TRAIL gene (Ad5hTRAIL) delivery into pancreatic islets prolongs normoglycemia in streptozotocin-induced diabetic rats.

Dirice E, Sanlioglu AD, Kahraman S, Ozturk S, Balci MK, Omer A, Griffith TS, Sanlioglu S. Hum Gene Ther. 2009 Oct;20(10):1177-89. doi: 10.1089/hum.2009.039.