Sialorphin Potentiates Effects of [Met]Enkephalin without Toxicity by Action other than Peptidase Inhibition.

This dose-response study investigated the effects of sialorphin on [Met]enkephalin (ME)-induced inhibition of contractions in mouse vas deferens and antinociception in male rats. Differences were compared among combinations of three chemical peptidase inhibitors: amastatin, captopril, and phosphoramidon. The ratio of potencies of ME in mouse vas deferens pretreated with both sialorphin (100 µM) and a mixture of the three peptidase inhibitors (1 µM each) was higher than that with the mixture of peptidase inhibitors alone at any dose.

Liposome-encapsulated hemoglobin enhances chemotherapy to suppress metastasis in mice.

Liposome-encapsulated hemoglobin with high O2 -affinity (P50 O2  = 10 mm Hg, h-LEH) was reported to enhance tumor radiosensitivity. We hypothesize that targeted O2 delivery to tumor hypoxia by h-LEH may also enhance chemotherapy to suppress tumor growth and metastasis in mice. Doxorubicin (DXR; 0.

Minimal inspiratory flow from dry powder inhalers according to a biphasic model of pressure vs. flow relationship.

Inhalation therapy using the dry powder inhaler (DPI) is now the first choice for obstructive pulmonary diseases. We previously measured relationships between inspiratory pressure (PI) and flow rate of almost all of the DPIs available in Japan, and described an importance of inspiratory efforts. In the present study, we further analyzed the data obtained in the previous study.

[Met5]enkephalin-Arg-Gly-Leu-induced antinociception is greatly increased by peptidase inhibitors.

Previous in vitro studies showed that the degradation of [Met(5)]enkephalin-Arg-Gly-Leu by cerebral membrane preparations is almost completely prevented by a mixture of three peptidase inhibitors: amastatin, captopril and phosphoramidon. The present investigations showed that the inhibitory effect of [Met(5)]enkephalin-Arg-Gly-Leu administered intra-third-ventricularly on the tail-flick response was increased more than 1000-fold by the intra-third-ventricular pretreatment of rats with three peptidase inhibitors. The inhibition produced by the enkephalin octapeptide in rats pretreated with any combination of two peptidase inhibitors was significantly smaller than that in rats pretreated with three peptidase inhibitors, indicating that any residual single peptidase could inactivate significant amounts of the octapeptide.