Local vascular changes induced by the cocarcinogen, phorbol myristate acetate.
نویسندگان
چکیده
SUMMARY One ,ig of phorbol myristate acetate, an active tumor promoting agent from croton oil, produces a severe, local vascular reaction in skin (ear) of CF1 and STS mice. The response is characterized by hyperemia and edema formation which can be quantitatively monitored by measuring uptake of circulating ‘251-labeled bovine serum albumin. Micro scopic detection of sites of endothelial injury in mice receiving i.v. carbon suspension shows the reaction to be primarily limited to venules. These microvascular changes are accompanied by mast cell degranulation in the affected tissues. Reactions develop about 1 hr after phorbol ester application, persist through 6 to 8 hr, and appear to be lessening in intensity by 24 hr. High doses (50 @.zg) of 7 ‘1 2-dimethylbenz(a)anthracene induce similar vascular changes, although of much lower intensity and after a longer delay interval. Antagonists of histamine, serotonin, and kinins produce mild, transient suppression of the local vascular response to the phorbol ester. Hydrocortisone and salicylate are without effect on this component of the tissue reaction. Local application of tosyl phenylalanine chioro methyl ketone, a protease inhibitor previously shown to suppress tumor promotion, affords a more sustained protec tion against the inflammatory activity of the phorbol ester.
منابع مشابه
Phorbol myristate acetate and catechol as skin cocarcinogens in SENCAR mice.
The enhancement of the carcinogenicity of benzo(a)pyrene (B[a]P) and beta-propiolactone (BPL) by the mouse skin cocarcinogens phorbol myristate acetate (PMA) and catechol were examined in female SENCAR mice, 30 per group. The carcinogen and cocarcinogen were applied simultaneously, three times weekly for 490-560 days. B(a)P and BPL were used at constant doses of 5 and 50 micrograms, respectivel...
متن کاملبررسی خصوصیات چسبندگی و فعالیت کشندگی ماکروفاژهای پریتونئال به کمک Phorbol Myristate Acetate و ارزیابی توان اکسیداتیو توسط Nitroblue Tetrazolium
Introduction: PMA is known to induce the differentiation of monocytes to macrophages. This agent also increases the killing effect of the monocytes/macrophages through oxidative burst and can be used as a stimulant for oxidative burst assay. The present experimental study was intended to investigate the in vitro effects of PMA on the differentiation, morphological changes, cell adherence and th...
متن کاملPhenylarsine oxide and ethanol prevent cell death of porcine polymorphonuclear leucocytes induced by phorbol myristate acetate.
In this study, we report that phenylarsine oxide and ethanol, both of which suppress a number of polymorphonuclear leucocyte functions including superoxide production, prevented the phorbol myristate acetate-induced cell death in a dose-dependent manner. These reagents had an inhibitory effect even after polymorphonuclear leucocytes were stimulated to produce superoxide by treatment with phorbo...
متن کاملNitric oxide opposes phorbol ester-induced increases in pulmonary microvascular permeability in dogs.
In addition to its effects on vascular tone, nitric oxide (NO) has been suggested to function as a participant in fluid homeostasis affecting interactions between the endothelium and circulating inflammatory cells. The role of NO in the increased microvascular permeability of acute lung injury, however, remains controversial. We investigated the hypothesis that NO opposes increases in pulmonary...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Cancer research
دوره 30 10 شماره
صفحات -
تاریخ انتشار 1970