Type 2 diabetes is more of a syndrome that is clinically diagnosed based on a consensus criteria; it is caused by/associated with a variety of reasons/traits and its etiology remains somewhat diffused.

First, you must decide what aspects of type 2 diabetes are you trying to duplicate (in as much as one can do so) in an animal model and then design a suitable experiment.

Strictly speaking, most aspects of type 2 diabetes cannot be replicated by merely destroying beta cells with STZ.

I agree with Tausif Alam's comment above.

STZ is a model of type 1 diabetes , i.e. destruction of beta cells.

STZ is not a model of type 2 diabetes. 

You need to reduce insulin action in peripheral tissues (i.e. liver so that hepatic glucose production cannot be suppressed and muscle so that blood glucose cannot be cleared)

This is most commonly achieved with feeding mice/rats high fat diet or a cafeteria style diet.

You could also think about knocking down/out components of the insulin receptor signalling cascade in the periphery although a lot of this has been done.

I agree as well. STZ is a beta-cell toxin and induced apoptosis to the beta-cells. High dose treatment kills very rapidly and is mostly used for short term observations. Low dose treatment over 5 days induced a slow death that will result in insulitis similar to type 1 diabetes...

In order to induce type 2 diabetes it would be easiest to use a high fat diet (HFD). You can buy such special food from most of the providers for rodent food pellets. They also offer a 'Western diet' (=high fat and high carbs). After 2-3 months of HFD the rats (or mice) will have a metabolic syndrome (weight gain, high triglyceride levels, moderately elevated blood glucose levels, delayed control of glucose challenge etc...)

I agree as well. But still you can follow the attached article for your research ... all the best :)

thanks to all of you sir.....

Hi Rooh,

I agree with all the previous comments. 

However, if you are just interested in the insulin resistance of T2D and dont want to spend time inducing it with HFD, you may be interested in S961.

http://www.ncbi.nlm.nih.gov/pubmed/20599729

Good luck,

Dario