THE ROLE OF PROTEIN KINASE C ON THE CONTRACTILE RESPONSES OF TESTICULAR CAPSULE AND SUPERFICIAL FASCIA TO HYDROGEN PEROXIDE

The present in vitro investigation had two primary aims: firstly to compare the responses of testicular capsule (TC) and cutaneous superficial fascia (SF) to hydrogen peroxide. Secondly to evaluate the role of protein kinase C (PKC) on these responses by use of bisindolylmaleimide1 chloride (BIM), a specific PKC inhibitor and phorbol-ester dibutyrate (PDBu), a specific PKC activator.  Rat TC and SF samples (six for each experiment) were removed and suspended under 2 g tension in an organ bath and, after stabilization, the responses to 200 nM PDBu or to a cumulative concentrations (0.2 to 1.6 µM final bath concentration) of hydrogen peroxide, in the absence and presence of 2µM (BIM), were recorded. Both TC and SF produced contractions in response to PDBu and in a concentration-dependent manner to hydrogen peroxide. These contractions were inhibited by BIM.  In conclusion, it seems that PDBu- and hydrogen peroxide-induced contraction in both SF and TC are mediated by activation of PKC. In addition, these findings suggest that macrophages, via release of hydrogen peroxide, may have an important role in mediating wound closure.