Related Experiment Videos
Effects of tetrodotoxin and OKY-046 in renal ischemia reperfusion
P J Garvin1, M L Niehoff, S M Robinson
1Abdominal Organ Transplant Division, St. Louis University Health Sciences Center, St. Louis, Missouri, 63110-0250, USA.
Abstract:
Ischemia reperfusion injury (IRI) contributes significantly to posttransplant graft dysfunction. An emphasis, therefore, has been directed toward the identification of novel renoprotective agents. In this study, the renoprotective effect of tetrodotoxin (TTX) alone, or in combination with a thromboxane synthetase inhibitor (OKY-046), was investigated in a 60-min warm ischemia, 72-h reperfusion, IRI rodent model. Unilateral nephrectomized rats were treated with the test vehicle alone, 1, 2, or 4 microgram/kg of TTX or 2 mg/kg of OKY-046 intravenously, either 15 min pre- or postischemia, or 2 microgram/kg TTX administered simultaneously with OKY-046 (2 mg/kg), following the ischemic interval. Baseline, 24, and 72 h mean plasma creatinine (Cr) and urea nitrogen (BUN) were compared. Maximal renoprotection was demonstrated by significantly improved 72-h Cr and BUN levels with the 2 microgram/kg of TTX or with 2 mg/kg of OKY-046, each administered after ischemia (ischemic control Cr = 8. 01 +/- 1.07 mg/dl vs TTX = 3.84 +/- 0.80 mg/dl, P = 0.008; vs OKY-046 = 4.0 +/- 1.5, P + 0.008; ischemic control BUN = 241.3 mg/dl +/- 32.8 vs TTX = 85.7 mg/dl +/- 18.7, P < 0.008; vs OKY-046 = 52.6 +/- 22.5, P = 0.008). The combination therapy utilizing TTX with OKY-046 resulted in reduced animal survival, demonstrating no renoprotection as measured with the biochemical parameters. These results support the renoprotective effects of TTX in a severe, rodent IRI model. The exact mechanism of action, as well as the therapeutic potential of TTX in preservation/transplantation, warrants further study.
Insights
Tetrodotoxin (TTX) and OKY-046 show renoprotective effects in rodent ischemia reperfusion injury (IRI) models when administered post-ischemia. Combination therapy reduced survival, indicating TTX
Area of Science:
- Nephrology
- Pharmacology
- Transplantation Immunology
Background:
- Ischemia reperfusion injury (IRI) is a major cause of graft dysfunction after transplantation.
- Identifying novel renoprotective agents is crucial for improving transplant outcomes.
Purpose of the Study:
- To investigate the renoprotective effects of tetrodotoxin (TTX) alone and in combination with OKY-046 in a rodent IRI model.
- To evaluate the impact of treatment timing (pre- vs. post-ischemia) on renoprotection.
Main Methods:
- A 60-minute warm ischemia and 72-hour reperfusion rodent model was used.
- Rats received varying doses of TTX or OKY-046 intravenously, either pre- or post-ischemia.
- Plasma creatinine and blood urea nitrogen levels were measured at baseline, 24, and 72 hours.
Main Results:
- The 2 microgram/kg dose of TTX or 2 mg/kg OKY-046 administered post-ischemia significantly improved 72-hour creatinine and BUN levels.
- Pre-ischemic administration or combination therapy with TTX and OKY-046 did not show renoprotective effects and reduced survival.
- TTX demonstrated significant renoprotection in a severe rodent IRI model.
Conclusions:
- Tetrodotoxin (TTX) exhibits renoprotective effects in a severe rodent IRI model, particularly when administered post-ischemia.
- OKY-046 also demonstrated renoprotective potential when given after the ischemic interval.
- Further research is needed to elucidate TTX's mechanism of action and therapeutic potential in transplantation.