opening and stored in ice cold oxygenated krebs solution overnight before use if necessary dog urethra proximal to prostate is cut into approximately 5 mm tings the rings are then cut open for contractile measurement of circular muscles human prostate chips from transurethral surgery of benign prostate hyperplasia are also stored overnight in ice cold krebs solution if needed the tissue is placed in a petri dish containing oxygenated krebs solution nacl 118 mm kcl 4 7 mm cacl 2 2 5 mm kh 2 po 4 1 2 mm mgso 4 1 2 mm nahco 3 2 0 mm dextrose 11 mm warmed to 37 u00b0 c excess lipid material and connective tissue are carefully removed tissue segments are attached to glass tissue holders with 4 0 surgical silk and placed in a 5 ml jacketed tissue bath containing krebs buffer at 37 u00b0 c bubbled with 5 co 2 95 o 2 the tissues are connected to a slatham gould force transducer 1 gram rat human or 1 5 gram dog of tension is applied and the tissues are allowed to equilibrate for one hour contractions are recorded on a hewlett packard 7700 series strip chart recorder after a single priming dose of 3 u03bcm for rat 10 u03bcm for dog and 20 u03bcm for human of phenylephrine a cumulative.