HAGHIGHI B, NODEHI H, TAZARVI M. THE EFFECTS OF GLUCAGON, INSULIN AND S TEROID HORMONES ON PHOSPHATIDATE PHOSPHOHYDROLASE ACTIVITY IN RAT LIVERS. Med J Islam Repub Iran 1998; 11 (4) :349-353
URL:
http://mjiri.iums.ac.ir/article-1-1080-en.html
From the Department of Clinical Biochemistry, Isfahan University of Medical Sciences, Isfahan, Islamic Republic of Iran.
Abstract: (4398 Views)
The effects of steroid hormones, glucagon and insulin on rat liver phosphatidate
phosphohydrolase (PAP) activity were studied both in vitro and in vivo. Incubation
of rat hepatocytes with each hormone showed that dehydroepiandrosterone (DHEA),
progesterone and testosterone increase PAP activity by 44.6, 37 and 36.9%,
respectively. Estradiol, however, decreased enzyme activity by 13.6% under the
same conditions. Similar results were obtained when these hormones were injected
in rats, in which PAP activity increased by DHEA (19.7%), testosterone (17%) and
progesterone (88%) and decreased by estradiol (38.8%). Incubation of the hepatocytes
with insulin however, did not change PAP activity significantly even at 144 J.LM
concentrations, whereas glucagon progressively stimulated the enzyme activity,
reaching 7 1% at 50 J.LM concentration under the same conditions. In rats injected with
glucagon, PAP activity also rose up to 79% after 30 min, after which time it declined
but remained above the control level at 45 min. The data imply the role of PAP
activity in the mechanism by which androgens and progesterone increase serum
triacylglycerols and decrease serum HDL-c and their possible regulation by these
hormones.