Effects of synthetic progestational steroids on liver and serum lipids in rats

Effects of norethisterone (NT) purified norethisterone (pure NT), norethynodrel (NE), medroxyprogesterone acetate (MAP), chlormadinone acetate (CMA) and desoxycorticosterone acetate (DOCA) on serum and liver lipid levels and serum lipoproteins were examined in both intact and estradiol-treated male rats. NT and NE caused a decrease in serum cholesterol and phospholipid levels, an increase in liver cholesterol level, no significant change in triglyceride levels of both serum and liver, with a significant change in serum lipoprotein patterns; a decreased in alpha- and beta-lipoproteins and a marked increase in pre beta-lipoprotein. Pure NT decreased serum cholesterol without causing any change in lipoprotein pattern. MAP, CMA and DOCA causee almost no effect on lipid levels in serum and liver, but CMA and DOCA increased alpha-lipoprotein and decreased beta- and pre beta-lipoproteins. An acute treatment with estradiol caused a decrease in alpha- and beta-lipoproteins and an increase in pre beta-lipoprotein with a decrease in serum lipid levels and an increase in liver lipids. By contrary, a chronic treatment with a marked hypercholesterolemia. This increase of alpha-lipoprotein in estradiol-treated rats was prevented by NT and NE, not affected or rather decreased by MAP but further increased with CMA and DOCA. These data suggest that the effects of synthetic progestational steroids on lipids are classified into two groups, 19-nortestosterone derivatives and 17alpha-hydroxyprogesterone derivatives including DOCA. The former caused a decrease in serum lipid levels with an increase of pre beta-lipoprotein and adecrease of alpha-lipoprotein. The latter caused almost no change or a slight increase in serum lipid levels with a decrease in pre beta-lipoprotein and an increase in alpha-lipoprotein, though it was not found in MAP.

Possible retention of the estrogen-binding capacity after endocrine ablation therapy in the rat and human breast cancer

The estrogen-binding capacity of the regrowing tumors after endocrine ablation surgery was estimated in the rat and human breast cancer. All of 4 tumors that had not had the estrogen receptor before oophorectomy did not show the estrogen-binding capacity after the procedure, in the mammary cancer in the Sprague-Dawley rat induced by 7,12-dimethylbenz[a]anthracene, whereas all the 4 tumors that had the receptor before the procedure showed the binding capacity after oophorectomy. In 4 patients who had been subjected to the major endocrine ablation therapy because of metastatic breast cancer with effective response, the secondary metastatic deposits of cancer showed the estrogen-binding capacity long after the endocrine ablation. The fact that regrowing tumors after complete or partial regression of initial tumors by endocrine ablation retain the estrogen receptor seems to be contradictory to the classical concept of autonomy in recurrence of the breast cancer after hormonal manipulation.

Regional changes in monoamine content and uptake of the rat brain during postnatal development

Regional norepinephrine (NE), dopamine (DA) and serotonin (5-hydroxytryptamine, 5-HT) contents in the developing rat brain were estimated. The rate of increase in NE content was the highest in diencephalon, followed by the lower brain stem, limbic-striatum, neocortex and cerebellum. With postnatal aging, DA concentration increased markedly in limbic-striatum, slightly in the neocortex and negligibly in other regions. In each region except cerebellum, 5-HT content increased gradually but the rate of increase in diencephalon was relatively high. Comparison of the kinetics of high affinity uptake of L-[3H]NE and [3H]5-HT between the neonatal and the adult brain indicated that Km values of L-[3H]NE and [3H]5-HT uptake were 2.9 X 10(-7) M and 1.7 X 10(-7) M respectively in neocortex, diencephalon and lower brain stem and 4.3 X 10(-7) M and 2.3 X 10(-7) M in limbic-striatum in the neonate as well as in the adult. Vmax values of both amines uptake differed regionally and the values in the neonate were lower than those in the adult in all regions. Limbic-striatum showed a higher Vmax value than other regions in uptake of both amines. These results suggested that innervation of monoaminergic neurons in the brain progressed with increasing age, that projections of both NE and 5-HT neurons were relatively high into hypothalamus and limbic-striatum and that DA neuron projections concentrated at striatum. Although the brain, except for limbic-striatum, showed neither regional nor developmental differences in affinity of L-[3H]NE and [3H]5-HT to synaptosomes, the density of nerve terminal of both monoaminergic neurons increased in all regions of the brain during postnatal development. In limbic-striatum, higher Km and Vmax values of both amines, uptake suggest the existence of both amines' uptake into DA terminal to some extent.

Regional changes in brain catecholamine content following administration of guanethidine to neonatal rats

Norepinephrine(NE), dopamine(DA) and serotonin(5-hydroxytryptamine, 5-HT) contents were estimated in the different regions of the developing rat brain following guanethidine injection at the neonatal period for the purpose of determining the influence of guanethidine on development of the monoamine neuron in the brain. Despite a nonsignificant change in the weights of all regions of the brain, guanethidine caused a significant reduction of NE content in the limbic-striatum at day 7 and 30 and an increase in mesencephalon-ponsmedulla at day 30. DA concentration in the limbic-striatum at day 7, 14 and 30 and in the neocortex at day 7 showed a decrease with guanethedine treatment. The change in 5-HT content was not induced with guanethidine in all regions and all days examined. These results suggest that guanethidine, crossing the blood-brain barrier at the neonatal stage, induced the degeneration of the nerve terminals and "collateral accumulation" of catecholamines in the central NE and DA neurons.

Lack of correlation between the presence of estrogen receptor and histological type of mammary cancer induced by 7,12-dimethylbenz[alpha]anthracene

The relation between the histological type and the presence of estrogen receptor or response to oophorectomy was investigated in the mammary cancer induced by 7,12-dimethylbenz[alpha]anthracene in Spargue-Dawley rats. The estrogen receptor was present in 75.0% (3/4) of poorly differentiated cancer and in 62.5% (10/16) of well-differentiated cancer. The histological degree of differentiation or grading of the rat mammary cancer did not affect the presence of the estrogen receptor or response to oophorectomy. In contrast, there was clearly a good correlation between the presence of the receptor and response to oophorectomy.

Alkaline phosphatase activity in the inner ear blood vessels of some mammals

The distribuation pattern of alkaline phosphatase in small blood vessels was studied histochemically in the stria vascularis and spiral ligament of various mammals. No or extremely weak activity of the enzyme was demonstrated in the walls of the blood vessels in bat and rabbit, while moderate to intense activity was found in guinea pig, cat, squirrel monkey and man. There was a species difference in the phosphate metabolism in the walls of the inner ear blood vessels.

Alkaline phosphatase activity in the inner ear of fetuses, newborn and adult guinea pigs

The distribution pattern of alkaline phosphatase in the inner ear of fetuses, newborn and adult guinea pigs is described. In the inner ear of fetuses, remarkable alkaline phosphatase was noted throughout the entire tissue of spiral ligament, statoacoustic nerve fibers and the wall of small blood vessels. In newborns, however, less enzyme activity was seen in the spiral ligament and statoacoustic nerve. In adult guinea pigs, no enzyme activity was detectable in the spiral ligament and statoacoustic nerve fibers except for the wall of small blood vessels and efferent nerve fibers. It is evident that the distribution pattern of alkaline phosphatase is altered during the development of the inner ear of the guinea pig.