Dear Abdulbaset

The dose that you intend on using is extremely high.

We normally inject IP with a single dose of 60mg/kg and still find it to be lethal in some instances. Depending on what you want to do, I would advise that the 60mg/kg concentration would suffice.

Anaesthetizing the animals might help with decreasing stress, but it is the actual impact of the STZ that will cause the major mortality rates.

Regards

Dear Prof. Stefan,

Thank you for your valuable advice and guidance.

I am looking for diabetes-induced cardiac fibrosis. My impression is that a higher dose will bring me closer to that goal. I did not find any articles that they have examined the effect of different doses of STZ on the cardiac fibrosis!

Besides, is the strain of mice suitable for that purpose?

I have no experience with mice, we use Wistar rats and he lower concentrations are definitely suitable to show changes in cardiac function/pathology.

Dear Prof. Stefan,

Thank you for taking the time to share all of that great information with me.

Best wishes to you for success in your career and life!

Dear Prof. Stefan,

Can I keep the diabetic rats for a long time? About 16 weeks

Once the model has been established and animals are stable, they will survive for a number of week if fed and properly hydrated.

I never used the high dose of STZ like you have tried. Have you looked at the pathology o pancreas in those dead mice? I have used a much smaller dose of STZ, like 60 mg/Kg of body weight given intraperitoneally. The blood glucose would rise in the matter of within two weeks. In fact, when we examined the pancreas, it would show significant infiltration of lymphocytes like we saw in the human pancreas of Type 1 diabetes. That was the model we used to study Type 1 diabetes. Interesting, when we applied 2 seconds of electric shock to mice in uncertain time, it created enough stress to the animals. That cycle of stimulation actually prevented the occurrence of diabetes. We have used the model to study Type 1 diabetes. I do not know what is the purpose of your study.

My study was published in Psychosomatic Medicine, 181;43:431.

Shih-Wen Huang, MD

University of Florida

Hi Abdulbaset,

Regarding the dose you want to inject, as Prof Stephan said, that’s high: so you could also imagine to inject 50mg/kg everyday for 5 days, it’s stressful for the mice but it works ....

As a matter of fact, I’d say the bigger issue you’ll face is to maintain a survival rate high enough for you to conduct your experiments after 16 weeks of diabetes, so here are a few tips for you:

1) Provide mice with fresh litter and a full load of water every day

2) After a few weeks, your diabetic mice are gonna turn weak and will display a lower physical activity, so instead of giving them cotton sticks for them to build a nest, you can use pieces of towel paper, so it’s easier for them to torn it appart

3) Also, if they are available in your animal facilities, you should use feeding bottle with a loooonger stick, it will make it easier for your mice to stay hydrated

Sorry, that’s all that I’ve got, I hope you’re gonna get more advices from other people !

Good luck,

Hugo

Dear Abdulbaset!

I have used the 150mg/kg STZ protocol in Swiss mice for many years. It is a very good protocol for severe diabetes induction but the death rate is really high( about 40%).

I'm not sure about to keep them during 16 weeks after induction.I use to keep them during 3 weeks after induction.

Anyway, I use to keep a 30% glucose solution during 24 ou 48 hours after induction. It heps to prevent the death by the initial hypoglycemia. I also change the cages every day to avoid the death by cold exposure ( high urinary rate ).

I hope I had helped.

Good luck.

Based on the responses from many friends on this column, I could see may are engaged in the diabetic study using STZ infection.

I suppose the dose could be varied pending on the purpose of your study.

Using smaller doses could cause diabetes that is characterized with significant infiltration of lymphocytes in the islets of pancreas.

If interested, I would list two publications of mine for your references.

1. Diabetes 1977;26 (Supple 1) 380

2. Clin Exp Immunol 1981;43:425.

Shih-Wen Huang, MD

University of Florida

Use some glucose in the first 2-3 days solution in order to keep them going into severe hypoglycemia because of the sudden release of insulin from the islets. Best of luck.

Dear all,

I really appreciate the great information and advice you have provided.

I wish you all the best in your future endeavors.

Playing with the dosage of the STZ does not help much in reducing mortality. You have to use Nicotinamide protection before your STZ injection. Please use the the streptozotocin-nicotinamide model (Erukainure et al., 2017; Noor et al., 2017). Basically the rats are first injected intraperitoneally with nicotinamide (120 mg/kg bw), then intravenously with streptozotocin (60 mg/kg bw) 15 minutes later. The animals in the control groups are injected with the required volume of citrate buffer and normal saline only.

Regards

Dear Abdoulbaset,

I have more than 25 years of experience with animal models of diabetic cardiomyopathy. The 150 mg/kg dose is extremely high and the mortality at 16 weeks will be near 100%. The doses of 120 mg/kg is also high.

With the doses of 60 mg/Kg or higher you will have a type 1 diabetes from toxic origin and provably you will have problems to publish your data in a medium/high impact journal.

The best accepted mouse model of type 1 diabetes consist in five daily ip injections of 50 mg/kg. This way you have a mouse model of type 1 diabetes from immflamatory origin. We have worked with this diabetic animals for up to 8-10 weeks.

We have also experience in rats, and in our rat model the cardiac fibrosis is well stablished in less than 4 weeks.

Good luck,

Oscar

Very good advice. I have worked on STZ model for many years too, as I indicated in my publications. My purpose of the work was to find the way to alter the clinical course of diabetes or even attempted to prevent the occurrence of insulin dependent diabetes.

Since I have no idea what the intention of the study by the first inquirer on this subject, I could only cite our own past experience. Many others responded the same way. Based on the responses, I am sure the inquirer has gained many valuable information.

Shih-Wen Huang, MD

I am a research specialist working on a Diabetes & Atherosclerosis project and will be inducing diabetes on our transgenic mice soon. I'm happy to have read all these comments, it is so nice to have this information ahead of time before injecting the mice. Thank you everyone.

Article Animal Models of Cardiac Fibrosis

May be useful to you..

Dear Basit

I have practical experience with mice, rat and rabbits etc.

First of all the dose you are using is too high. I will suggest 70 mg/Kg BW.

You can reduce the mortality rate up to 99% if you will follow my instructions. Before starting the experiment, you must give high dose of glucose in their drinking water, at least 3 days before and 2 days after... the administration of STZ. while On the day of administration you must give your animals glucose orally.

NOTE: the induction of Diabetes is caused by the destruction of Beta-Cells, and ultimately in the first couple of days chronic-hypoglycemia is caused. and that is the real cause of the death.

Thanks

Dr. Izhar Ahmad

Dear all,

Thank you for taking the time to share all of that great information with me. Your support, encouragement and advice have been extremely helpful.

Best wishes

You are welcome. Best of luck for your research.

Shih-Wen Huang,MD

I agree with@Stefan S Du Plessis

greeting