Specific regulation by steroid hormones of protein kinases in the endometrium. 2. Alteration in levels of protein kinases in human endometrium during the menstrual cycle

The alteration in the levels of multiple protein kinases has been studied in human endometrium during the menstrual cycle. Protein kinases were examined in the cytosol fraction and separated by DEAE-cellulose column chromatography. The level of type I adenosine 3',5'-monophosphate-dependent (cAMP-dependent) protein kinase was higher than that of type II cAMP-dependent protein kinase at the proliferative phase. At the late secretory phase, type I cAMP-dependent protein kinase markedly decreased, whereas type II cAMP-dependent protein kinase remained at the same level. Therefore, type II cAMP-dependent protein kinase was exclusively predominant at this phase. cAMP-dependent and cAMP-independent protein kinases with protamine increased more at the late secretory phase than at the proliferative phase. The results presented demonstrate a specific alteration in protein kinase activities during the menstrual cycle and are compatible with those obtained in rabbit endometrium (the preceding paper).

Specific regulation by steroid hormones of protein kinases in the endometrium. 1. Alteration by estrogen and progesterone in levels of protein kinases in rabbit endometrium

The alteration in activities of multiple protein kinases has been studied in the endometrium of a rabbit treated with estrogen and progesterone. The administration of estrogen or progesterone to the castrated rabbit resulted in a remarkable increase of total activity in the cytosol fraction of the endometrium. The administration of estrogen caused an increase of type I adenosine-3',5'-monophosphate-dependent (cAMP-dependent) protein kinase and a slight decrease of type II cAMP-dependent protein kinase. In contrast, the treatment with progesterone after priming administration of estrogen brought about an increase of type II cAMP-dependent protein kinase and a decrease of type I cAMP-dependent protein kinase. Therefore, the activity ratio of type II to type I decreased by estrogen and increased by progesterone. The simultaneous administration of cycloheximide abolished the stimulatory effect of respective hormones on the level of each protein kinase. The activity profile of protein kinases on DEAE-cellulose column after ovulation caused by the administration of human chorionic gonadotropin to a non-castrated rabbit was similar to that of the rabbit treated with progesterone. The results presented demonstrate the specific regulation by the steroid hormones of de novo synthesis of protein kinases in the target organ.

Effect of trichloroacetic acid treatment on certain properties of spores of Bacillus cereus T

Spores of Bacillus cereus T treated with trichloroacetic acid (6.1--61.2 mM) were compared with untreated spores, and as the concentration of the chemical increased, the following alterations in spore properties were found: (1) the extent of germination decreased irrespective of the germination medium used; (2) the spores became sensitive to sodium hydroxide (1 N) and hydrochloric acid (0.27 N), but not to lysozyme (200 micrograms/ml); (3) loss of dipicolinate increased on subsequent heating; and (4) the spores became more sensitive to heat. However, trichloroacetic acid-treated spores were still viable and there was no significant change in spore components. The mechanism of action of trichloroacetic acid is discussed.

Effect of papaverine on Ca2+ uptake by a mitochondrial fraction isolated from rat uterine smooth muscle

A mitochondrial fraction was isolated from rat uterine smooth muscle. The effect of papaverine (3 X 10(-6), 10(-5), 3 X 10(-5), 10(-4) M) on Ca2+ accumulation by the fraction was studied. The effect of papaverine was changed by using different substrates for Ca2+ accumulation. Papaverine inhibited the Ca2+ accumulation supported by glutamate plus ATP concentration-dependently. The Ca2+ accumulation supported by ATP alone was also inhibited. On the other hand, the Ca2+ accumulation supported by succinate and ATP was increased by papaverine. The effect was not concentration-dependent; papaverine (3 X 10(-5) M) was the most effective concentration for the effect with a shorter incubation (2 min).

Purification of histamine receptor (VI). An improved double labeling method with "double protection"

Studies were done on the specific labeling of the histaminergic H1-receptor of the longitudinal smooth muscle of cat small intestine. A procedure involving 'double protection' combined with the double labeling technique was developed. The first protection was the usual with a protective antihistamine, promethazine, and the second was cross protection of non-specific sites with non-hitaminergic drugs, thioriazine and atropine. Muscle tissue protected with promethazine against non-radioactive dibenamine was treated with 3H-dibenamine in the presence of these second protectors. The second protectors covered non-receptor sites which had been protected from non-radioactive dibenamine with promethazine. The dose-response curves were carefully checked in each experiment to confirm that the second protectors did not interfere with the specific coverage provided by the first protector. Finally 14C-dibenamine was applied to measure non-specific binding after which the labeled muscles were fractionated and the radioactivity was counted. The specificity of labeling achieved in the receptor-rich fraction by this method is discussed.

Fine structure of ependymal cells in the median eminence of the frog and mouse revealed by freeze-etching

Freeze-etched preparations of the ventricular surfaces of ependymal cells clearly reveal the presence of pinocytotic vesicles opening into the third ventricle and large vacuoles formed by broad cell projections. The density of the vesicular openings is approximately 20 per micron2. The ependymal cells in the median eminence of the frog are adjoined by tight junctions comprised of five to eight interconnected junctional strands, whereas near the median eminence in the mouse only one to two such strands form the tight junction of the ependymal cells. Gap junctions between the adjacent ependymal cells are detected near the median eminence in the mouse but not in the frog.

Purification of histamine receptor, (III) Characterization of receptor rich membrane fraction of small intestinal smooth muscle of the cat

Intracellular localization of histamine receptors in small intestinal smooth muscle of the cat was studied by investigating distribution of marker enzymes in the receptor rich fraction. Distribution of membrane markers coincided with that of the radiochemically labeled receptor fraction. Membrane fraction was further purified and it was concluded that the histamine receptor rich fraction is mainly composed of cell membrane. The chemical composition of the fraction lent support to this conclusion.

Purification of histamine receptor. (IV) Specificity of binding of various drugs to the histamine receptor-rich fraction and to solubilized binding sites

Studies were made on tritiated histamine binding to the receptor-rich membrane fraction and solubilized sites and its displacement by various drugs. H1-Agonists and antagonists displaced histamine most effectively. A H2-agonist and atropine were less effective and propranolol, phentolamine and imidazole acetic acid had little effect. The solubilized binding sites showed the same specificity of binding as the membrane fraction. Membrane fragments had two binding constants, whereas solubilized sites had only one. Solubilized sites bound similar amounts of histamine and dibenamine: the latter was applied to intact tissue under conditions which would presumably cause specific binding to histamine receptors. These binding characteristics show that the method used was adequate for purification of histamine receptors from smooth muscle of cat small intestine.

Histamine receptor-mediated calcium ion movement in a receptor-rich microsomal fraction

The histamine receptor-rich microsomal fraction from the longitudinal muscle of cat small intestine, which consists of membrane vesicles, was loaded with 45Ca ions and the Ca ion efflux from it was examined. Histamine increased the efflux of 45Ca ions. The effect of histamine was blocked by diphenhydramine. Histamine had no effect on the histamine receptor-free microsomal fraction from dog small intestine muscle. This suggests that the ion movement may be mediated by histamine receptors.