Accumulation of &lt;sup&gt;99m&lt;/sup&gt;Tc-Tetracycline in Lung Infarction Area

The development of strategies to ameliorate post-myocardial infarction (MI) remodeling and improve function continues to be an area of clinical importance. Use of steroids for this purpose is controversial since the effects of timed treatment on relevant inflammatory, biochemical and structure/function endpoints are unclear. In a previous report, we demonstrated that use of doxycycline pre-treatment improves post-MI remodeling and passive left ventricular (LV) function. However, the effects of timed doxycycline post-MI treatment are unknown. To examine these issues, we performed a study using a rat MI model. Animals were administered one of the following: doxycycline (DOX), the corticosteroid methylprednisolone (MP), or aqueous vehicle. Treatment was given early, short-term (at time of MI to 24 h post-MI) or late, long term (2-7 days post-MI). Animals were sacrificed at 3, 7 or 42 days post-surgery. We assessed LV hemodynamics, pressure-volume, and pressure-scar strains, histomorphometry, inflammation via measurements of myeloperoxidase activity, and matrix metalloproteinase (MMP) activity. Late MP treatment yielded a robust right-shifted pressure-volume curve, which was accompanied by increased scar strains. Late DOX treatment yielded reduced average heart weight and size and preserved scar thickness. DOX treatment did not suppress inflammation, which contrasts with the suppressive effects of MP. Use of early or late MP yielded increased MMP activity in infarcted and non-infarcted regions. Early and late treatment with DOX yielded infarct-associated MMP activity levels comparable to those of vehicle-treated animals. In conclusion, results indicate that late use of MP yields adverse post-MI structure/function outcomes that correlate with suppression of inflammation and increased MMP activity. These observations contrast with those of DOX, in particular, late treatment where improved outcomes were observed in LV structure and were accompanied by the lack of suppression of inflammation.

show abstract

The Use of Antimicrobial Agents for Noninfectious Diseases

Berger¹

1985

Clinical Infectious Diseases

View full text Add to dashboard Cite

Accumulation of <sup>99m</sup>Tc-Tetracycline in Lung Infarction Area

Cited by 3 publications

References 4 publications

Mode of Action, Biotransformation and Pharmacokinetics of Antituberculosis Drugs in Animals and Man

Mode of Action, Biotransformation and Pharmacokinetics of Antituberculosis Drugs in Animals and Man

Effects of timed administration of doxycycline or methylprednisolone on post-myocardial infarction inflammation and left ventricular remodeling in the rat heart

The Use of Antimicrobial Agents for Noninfectious Diseases

Contact Info

Product

Resources

About