RESUMEN
OBJECTIVE:To study the pharmacological effects of saponin H,a new saponin isolated from Polygala tenuifolia Willd,on isolated smooth muscle and herat.METHODS:Isolated rabbit ileum,aorta strip,Langendorff heart,guinea pig trachea,and rat uterus were prepared.Their changes in tension 3 min after administration of H were recorded.RESULTS:19 and 76 μmol.L-1of H showed contracting on above-mentioned smooth muscles,with increasing their tensions by 64% and 167%,30% and 118%,20% and 50%,100% and 118%,respectively.19,38 and 76μmol.L-1 of H showed dose-dependent inhibition on heart,decreased contractile force by 20%,23% and 34%,and reduced the heart rate by 17%,20% and 35%,respectively,but failed to affect the coronary flow.The contracting action of H on uterus was not influnced by diphenhydramine,but partly attenuated by indomethacin.CONCLUSION:H excited the isolated smooth muscles but inhibited the heart.Its action on uterus was partly related to the activation of prostaglandin synthetase.
RESUMEN
Prostaglandin-synthetase activity has been measured in the microsomal fraction of developing toad (Bufo melanostictus) ovary using arachidonic acid as the substrate. Indomethacin (0·74 μΜ) and aspirin (0·35 μΜ) inhibit this activity. The activity is maximum in immature ovary and its level gradually decreases with maturity of the organ till the breeding season arrives, when it rises again. Time course study shows that the activity in vitro becomes steady after 3 min of incubation in all the cases, except the immature ones in which it sharply declines. Soluble supernatant was found to contain some inhibitory factor(s), which is partially inactivated by heating at 100°C for 5 min (~ 43%). Intraperitoneal injection of equine luteinizing hormone stimulates this enzyme activity in the mature ovary during non-breeding season. This suggests that similar to mammalians prostaglandin-synthetase, the toad ovary enzyme is also regulated by luteinizing hormone.
RESUMEN
The effects of several co-factors and bivalent cations on the activity of prostaglandin synthetase isolated from goat seminal vesicles were studied. Ca2+ appears to play a regulatory role in the biosynthesis of prostaglandin E2 by goat vesicular microsomes as the normal parabolic time course of synthesis changed to a sigmoid curve in the presence of 4 mM Ca2+ and to nearly a hyperbolic pattern when the microsomes were preincubated with the metal ions. The Ca2+ modulated reaction showed increased rate of prostaglandin E2 synthesis only when the period of incubation was extended beyond 30 min. The co-factor requirement of the goat enzyme was similar to that of the bovine and ovine prostaglandin synthetase systems.
RESUMEN
Thymus, lymph node and intestine (two pieces each) were taken from 20 adult guinea pigs and 10 adult rats. One piece was frozen in liquid nitrogen (-70℃) and cryostat sections were stained with Janszen and Nugteren (1971) method to demonstrate prostaglandin synthetase activity, Another piece was fixed in methanol, and paraffin sections were stained with HE and toluidin blue to demonstrate mast cell. Teased preparation of mesentery were stained by the same methods to show enzyme activity. Indomethacin inhibiting test was used as control. It is proven that the brown deposit represented the prostaglandin synthetase activity. These deposit existed in cytoplasm of mast cell, while and was absent in nucleus and specific granules. Prostaglandin synthetase positive mast cells distributed widely in lamina propria, axis of villi and submucosal layer in intestine, capsule, septa and medulla in thymus; capsule, trabecullum and paracortical zone of lymph node.