Phosphatidylcholine metabolism for energy production in sea urchin spermatozoa

Sea urchin spermatozoa use endogenous phosphatidylcholine (PC) to produce energy for swimming. The catabolism of PC was studied in Hemicentrotus pulcherrimus spermatozoa. Following incubation in sea water, the content of PC decreased and that of choline increased gradually, whereas phosphocholine maintained a constant level. Measurement of the radioactivity in metabolites converted from 1-palmitoyl-2-[1-14C]linoleoyl-PC, [choline-methyl-14C]dipalmitoyl-PC and 1-[1-14C]palmitoyl-lysophosphatidylcholine (LysoPC) showed that the major degradative pathway is PC----LysoPC----glycerophosphocholine----choline. 1-Palmitoyl-2-[1-14C]linoleoyl-PC and [1-14C]oleic acid were oxidized to 14CO2 in a cell-free system of spermatozoa. Sea urchin spermatozoa thus appear to quite likely obtain energy through the oxidation of fatty acid(s) from PC.

The influence of an egg-associated peptide on energy metabolism in sea-urchin spermatozoa: the peptide stimulates preferential hydrolysis of phosphatidylcholine and oxidation of fatty acid

A study was made of the effects of a sperm-activating peptide (SAP-I: Gly-Phe-Asp-Leu-Asn-Gly-Gly-Gly-Val-Gly) on energy metabolism in spermatozoa of the sea urchin, Hemicentrotus pulcherrimus. The swimming activity and respiratory rate in slightly acidic seawater (pH 6.6) have been shown to be somewhat less than in normal seawater (pH 8.2). Little change occurred in sperm lipid levels during incubation in seawater at pH 6.6. The addition of SAP-I to seawater at pH 6.6 enhanced the consumption of endogenous phosphatidylcholine (PC), with no change in the levels of other lipids. SAP-I also caused increase in 14CO2 production from exogenous [1-14C]oleic acid following incubation of spermatozoa at pH 6.6. However, the stimulated levels of PC consumption and fatty acid oxidation with SAP-I at pH 6.6 did not exceed those at pH 8.2. At pH 8.2, SAP-I had no effect on PC metabolism. Activities of phospholipase A2 and fatty acid oxidation were markedly influenced by pH and increased at pH exceeding 7. SAP-I is thus concluded to stimulate sea-urchin sperm energy metabolism which depends on the oxidation of endogenous PC. It follows from these results that PC metabolism is activated following increase in the intracellular pH of spermatozoa.

High incidence of 17p13 chromosomal abnormalities in malignant histiocytosis

Cytogenetic analyses of three patients during autopsy who had a pathologic diagnosis of malignant histiocytosis and of one patient who was strongly suspected to have malignant histiocytosis because of her clinical and hematologic findings were done. All three patients studied with bone marrow specimens showed polyploidy (3.4-20%). Two of three patients with chromosomal abnormalities showed 17p+ markers with a breakpoint at 17p13. Seven of 22 previously reported malignant histiocytosis patients (32%) with descriptions of detailed whole karyotypes have the 17p+ markers, including two of the authors' patients. Five of seven patients with 17p+ involved 17p13. Although breakpoints at the 17p+ in the remaining two were not described, their karyotypes were shown to possibly involve 17p13. The high incidence of this abnormality is not considered accidental, and this breakpoint is not usual in many other neoplastic disorders. These facts may indicate that 17p13 chromosome abnormality is a specific change of malignant histiocytosis.

Optical computing using optical flip-flops in Fourier processors: use in matrix multiplication and discrete linear transforms

An architecture and the algorithms for matrix multiplication using optical flip-flops (OFFs) in optical processors are proposed based on residue arithmetic. The proposed system is capable of processing all elements of matrices in parallel utilizing the information retrieving ability of optical Fourier processors. The employment of OFFs enables bidirectional data flow leading to a simpler architecture and the burden of residue-to-decimal (or residue-to-binary) conversion to operation time can be largely reduced by processing all elements in parallel. The calculated characteristics of operation time suggest a promising use of the system in a real time 2-D linear transform.

[Application of Holter electrocardiography to exercise testing for the group examination of school children: comparison between obese and normal children]

Application of Holter electrocardiography to an exercise test for heart function is useful in the group examination of school children. The circulatory responses to a step test among obese boys and girls and control were as follows: 1. Four cases of arrhythmia were detected, of whom 2 cases were discovered during exercise. ST-segment depression of 0.1 mV or more during and after exercise was recognized in 29 cases, 27 of the junctional- and 2 of the sagging slope, with a higher percentage in obese girls than in normal girls. 2. Serial ECG records during the procedure, performed for all children with the same single-step test, showed differences in the circulatory responses among the test groups. The load was estimated to be 76-86% of the maximal heart rate predicted by Cummings, with obese and girl groups being higher than other groups. The comparison revealed that the heart rate (HR) responses to exercise done by the boys increased faster than those by the girls at 1 minute after exercise. There were differences between obese and control and between boys and girls in HR at recovery, and also in HR before and 4 minutes after exercise between two sexes, which findings agree with other reports. 3. Concerning anthropometric factors, either the skinfold thickness or the obesity index was related to the HR at the peak of the exercise as well as immediately after it and to the half time. By contrast, the arm muscle diameter was found unrelated to the HR. Using this method, applied these combination of Holter ECG and step test to a group examination, we got ECG data for 254 subjects, 97.5% of which were suitable for analysis. We found this method to be effective for detecting ECG changes and for determining HR responses to exercise. This method is safe, simple, and inexpensive and is applicable to examination not only for school children but also for different population groups, for the estimation of circulatory responses.

Mediation of cyclic adenosine 3',5'-monophosphate in 1-methyladenine production by starfish ovarian follicle cells

Resumption of meiosis in starfish oocytes is induced by 1-methyladenine (1-MeAde) produced by ovarian follicle cells under the influence of a gonad-stimulating substance (GSS). It has also been reported that concanavalin A (Con A) and two serine proteolytic enzymes (trypsin and Pronase) can stimulate 1-MeAde production. This study was undertaken to determine if 1-MeAde production induced by these compounds is mediated through elevation of cAMP in starfish (Asterina pectinifera) follicle cells. GSS at a concentration of 0.1 mg/ml significantly stimulated 1-MeAde accumulation in extracellular medium after 1-2 hr of follicle cell incubations. GSS also caused a four- to fivefold increase in intracellular levels of cAMP. The continuous presence of GSS was required for the maintenance of elevated levels of cAMP and 1-MeAde. Basal levels of intracellular cGMP were only about 20% of those of cAMP and were not influenced by treatment with GSS. At 1 mM, 3-isobutyl-1-methylxanthine (IBMX), a potent phosphodiesterase inhibitor, stimulated both 1-MeAde and cAMP production in a concentration-dependent manner. Con A and two serine proteases also raised both cAMP and 1-MeAde production. Con A-induced (1.0 mg/ml) increases in cAMP and 1-MeAde were greater than the response to GSS (0.1 mg/ml) and were completely suppressed by treatment with alpha-methyl-D-mannoside (10 mM), a competitive inhibitor of Con A. These results strongly suggest that cAMP is a second messenger in the production of 1-MeAde by starfish ovarian follicle cells.

Fatty chain composition of phospholipids in sea urchin spermatozoa

1. An analysis was made of lipids extracted from the spermatozoa of the sea urchins, Hemicentrotus pulcherrimus and Anthocidaris crassispina. 2. Nearly all the lipids from both species consisted of phospholipids (about 80%) and cholesterol (about 14%). Triglyceride and cholesterol ester were present in trace amounts. 3. The fatty acid composition of each phospholipid was determined by gas-liquid chromatography. In both species, the fatty acid consisting of phosphatidylethanolamine was of the unsaturated type for the most part, while cardiolipin was comprised to a considerable degree of saturated fatty acids. In phosphatidylcholine and phosphatidylserine from H. pulcherrimus sperm, unsaturated fatty acid content was somewhat higher than that in phospholipids from A. crassispina sperm.

Muscarinic receptor binding and Ca2+ influx in the all-or-none response to acetylcholine of isolated smooth muscle cells

Isolated smooth muscle cells from guinea pig taenia caecum were prepared by collagenase digestion. Isolated single smooth muscle cells showed an all-or-none response to acetylcholine (ACh) under our experimental conditions. A Scatchard plot of the specific binding of [3H]quinuclidinyl benzilate (QNB) to the cells gave a straight line, and the KD and Bmax values were calculated as 0.18 +/- 0.03 nM and 1.11 +/- 0.10 pmol/mg protein, respectively. ACh competitively inhibited the specific binding of [3H]QNB in a concentration-dependent manner. Thus, although the cells showed an all-or-none response, ACh bound to the receptor concentration dependently. The contraction of the cells in response to ACh was inhibited in a concentration-dependent manner, by nicardipine suggesting that the contraction of smooth muscle cells in response to ACh depended on the influx of extracellular Ca2+. The ACh-stimulated increase of the Ca2+ influx was very rapid and correlated well with the contraction of the cells; it decreased after reaching a maximum. The all-or-none response of the cells could be due to a rapid influx of Ca2+. These results suggest that ACh binds to its receptor in a concentration-dependent manner, and that when the binding reaches a certain threshold, a rapid influx of Ca2+ occurs and the cells show an all-or-none response, followed by an efflux of Ca2+.

Energy metabolism of sea urchin spermatozoa, with phosphatidylcholine as the preferred substrate

Phosphatidylcholine content in the spermatozoa of the sea urchin, Hemicentrotus pulcherrimus, decreased rapidly during incubation with sea water. Sea urchin sperm contained approx. 85% phospholipid in total lipid. Phosphatidylcholine (PC) was the principal lipid. Other phospholipids, however, remained at constant levels during incubation. Although the free fatty acid content gradually increased following dilution of dry sperm in sea water, the amounts of triacylglycerol and cholesterol ester were extremely low. Analysis by gas-liquid chromatography indicated most of fatty acid moieties in PC to be polyenoic. PC composed in part of unsaturated fatty acids was consumed to a greater extent during incubation than that consisting of saturated fatty acids. Furthermore, 1-palmitoyl-2-[1-14C]linoleoylphosphatidylcholine was transformed to 14C-labelled free fatty acid in a subcellular system. Thus, possibly, phospholipase A2 is present in sea urchin sperm. Also, [1-14C]oleic acid was immediately oxidized to 14CO2 by sperm. It is thus concluded that sea urchin sperm use phosphatidylcholine as a substrate for energy metabolism.

Egg yolk paste for determining some food poisoning bacteria

Egg yolk, aseptically prepared from fresh eggs, was partially dehydrated with a 40% high fructose corn syrup solution, and 10% salt was added. This salted yolk paste was added to mannitol salt agar for the detection of Staphylococcus aureus, to NaCl-glycine Kim and Goepfert medium for detection of Bacillus cereus, to Clostridium welchii agar for detection of C. perfringens, and to Gifu anaerobic medium for detection of C. botulinum. These food poisoning bacteria showed the same lecithovitellin (LV) reaction on these media as on the same media prepared with fresh egg yolk. The yolk paste could be stored at -20 C without freezing and did not show any bacterial growth after holding at 25 C for 30 days. The increased salt content resulted from the addition of salted yolk paste to the media did not inhibit the growth of the food poisoning bacteria used in these experiments. For the identification of the food poisoning bacteria used in this work, and which give a LV reaction, salted yolk paste is more convenient to use than yolk separated from fresh shell eggs.

Effect of Ca2+ deprivation on short-term desensitization of isolated smooth muscle cells showing an all-or-none response to acetylcholine

1. Short-term desensitization of the contractile response of isolated smooth muscle cells from guinea pig taenia caecum to acetylcholine was examined in the absence of external Ca2+. 2. Isolated smooth muscle cells contracted to 10(-7)-10(-6) M acetylcholine, showing an all-or-none response. 3. Desensitization was induced by incubating the cells with 10(-4) M acetylcholine for 10 min in Ca2+-free solution. 4. Desensitized cells showed an all-or-none response but required a higher concentration of acetylcholine for induction of contraction, indicating that the desensitization was due to a change in the threshold concentration. 5. Desensitization is suggested to be induced before massive influx of Ca2+ into the cells.

Regulatory functions of cyclic adenosine 3',5'-monophosphate in 1-methyladenine production by starfish follicle cells

The biosynthesis of 1-methyladenine (1-MeAde) in follicle cells of the starfish, Asterina pectinifera, occurred in response to a gonad-stimulating substance (GSS). Simultaneously with 1-MeAde production, the intracellular cAMP level immediately increased following the administration of GSS. This level in follicle cells markedly depended on GSS concentration. Although 1-MeAde production was also induced by 1-methyladenosine, it caused no increase in cAMP content. It thus appears that the effect of GSS on starfish follicle cells results in the receptor-mediated formation of cAMP.

Desensitization of isolated smooth muscle cells from guinea pig taenia caecum to acetylcholine

The role of tissue organization of smooth muscle in short-term desensitization to acetylcholine (ACh) was examined by studying the desensitization of isolated single cells from guinea pig taenia caecum. Cells were isolated by collagenase digestion. The conditions during cell isolation were adjusted to obtain cells that showed repeated contractions. The cells contracted on treatment with 10(-7)-10(-6) M ACh, showing an all-or-none response. Desensitized cells also showed an all-or-none response but required a higher concentration of ACh for induction of contraction; i.e., the magnitude of their maximal response was not changed appreciably but the threshold concentration of ACh for their contraction was raised. Incubation of the whole tissue with 10(-4) M ACh for 10 min also caused desensitization. This desensitization was accompanied by reduction of the contractile response at intermediate concentrations. The mode of desensitization of isolated cells determined from the average response of the isolated cells was almost the same as that of whole muscle. It is concluded that the desensitization occurred in each cell irrespective of its tissue organization and that the desensitization was due to an increase of the threshold for contraction to ACh of each cell.

[Regional differences of the clear cells in the mouse epididymal duct: a histological study]

Age-related changes in the clear cells and responses of the clear cells after ligation at the efferent duct or the junction between the epididymal head and tail were examined by light and electron microscopy with special reference to the regional differences in the epididymal duct in mice. In adult mice, the epididymal duct is divided into five segments (I-V) and the lumen distal to Segment II contains PAS-positive material in addition to spermatozoa. The clear cells had vacuoles and PAS-positive granules containing acid phosphatase. Electron microscopy suggested that the clear cells ingest the luminal material and condense it into the PAS-positive granules in the basal cytoplasm. The clear cells first appeared at 20 days of age following appearance of the PAS-positive material in the lumen. After 40 days, the clear cells became frequent and well-developed containing much PAS-positive granules in the distal Segment IV and Segment V, which were filled with abundant spermatozoa and PAS-positive material. After ligation at the efferent duct, the duct distal to Segment II was filled with PAS-positive material but no spermatozoa, and the clear cells in the proximal Segment V became to contain more abundant and large PAS-positive granules. After ligation at the junction of the epididymal head and body, the luminal PAS-positive material was scarecely seen in Segment IV but densely in Segment V and the clear cells were more developed in the distal Segment IV. The findings suggest that the clear cells are especially developed to absorb the luminal PAS-positive material in the distal region of the epididymal duct and may absorb different PAS-positive material in different segments.

[PAS-positive epithelial cells in the deferent duct in mice: light microscopic observations]

The deferent duct in adult mice was observed by light microscopy, mainly in methacrylate sections stained with PAS, hematoxylin and fast green. A region of the deferent duct just following the epididymal duct is lined with the principal cells with stereocilia and epithelial cells containing strongly PAS-positive granules. The PAS-positive epithelial cells have no stereocilia and show PAS reaction in the tytoplasm just under the luminal surface. The PAS-positive granules are usually less than 1 micron in diameter, often seen in 1 to 2 micron wide vacuoles, and distributed densely in the supranuclear or infranuclear cytoplasm, or occasionally in the whole cytoplasm. The granules or contents of the vacuoles reveal to have acid phosphatase. These cells occupy 5 to 10% of the epithelial cells lining the deferent duct at the region of the junction with the epididymal tail. The PAS-positive epithelial cells of the deferent duct, as well as the clear cells of the epididymal duct, may function in relation to the PAS-positive material in the lumen of the duct.

The influence of temperature on the functions of cultured Sertoli cells

Three functions of Sertoli cells were examined with cells from rats aged 13 and 25 days at 34 C, 38 C, and 40 C, namely protein synthesis (incorporation of amino acids into material precipitated by trichloroacetic acid), transport of alpha-aminoisobutyric acid, and production of lactate. A fourth function, namely production of cAMP was examined at two temperatures (34 C and 38 C) in cells from rats aged 25 days. In all cases, activity was greater at 38 C than at 34 C and greater at 40 C than at 38 C. Lysate of Sertoli cells showed similar differences in protein synthesis at the three temperatures, again at both ages. Protein synthesis was higher at 38 C than at 34 C in Sertoli cell-enriched tubules from rats aged 25 days and in Sertoli cells from normal rats of the same age cultured on rat tail collagen. The difference in protein synthesis at the two temperatures was seen whether the cells were cultured, before the experiment, for 7 days at 38 C or at 34 C. Production of cAMP by Sertoli cells was greater at 38 C than at 34 C. It is concluded that Sertoli cells do not show in vitro any inhibitory effect of body temperature on any of the functions tested, but on the contrary, are more active at body than at scrotal temperature. The possible significance of the differences seen is discussed.

The influence of insulin and insulin-like growth factor-I on hexose transport by Sertoli cells

Insulin stimulates the synthesis of lactate by cultured Sertoli cells prepared from rats aged 13 days, to a much greater extent if glucose is present in the incubation medium than when it is absent. Insulin also stimulates the transport of 3-O-methyl-D-[14 C]glucose into cultured Sertoli cells. This increased transport results from a decrease in the Michaelis-Menten constant (Km) of methylglucose for the transport system without change in maximum velocity (Vmax). Moreover, insulin stimulates influx of the glucose analog and is without effect on efflux. Insulin does not alter transport of methylglucose in peritubular fibroblasts or in mixed populations of germ cells. It was observed that whereas insulin stimulates transport of methylglucose at micromolar concentrations, insulin-like growth factor I (IGF I) exerts the same effect at nanomolar (physiological) concentrations. Moreover, the response to insulin plus IGF I is the same as the maximal responses to either hormone alone. In view of the effects of insulin and IGF I on glucose transport by Sertoli cells and in view of the importance of lactate as a substrate for germ cells, it is suggested that IGF I may be important for the development of normal germinal epithelium in rat testes.

Effects of Quin-2, an intracellular Ca chelator, and TMB-8, an intracellular Ca antagonist, on the short-term desensitization to histamine in guinea pig taenia caecum

The effects of Quin-2-acetoxylmethylester, an intracellular Ca ion chelator, and 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate-HCl (TMB-8), an intracellular Ca antagonist, on short-term desensitization to histamine were tested in guinea pig taenia caecum. Desensitization was induced by incubating the muscle with 10(-4) M histamine for 30 min and the recovery from the desensitization needed ca. 90 min. Both Quin-2-acetoxylmethylester (50 microM for 120 min) and TMB-8 (5 microM for 20 min) suppressed the desensitization. Modes of action and structures of both agents are quite different but both may reduce the availability of intracellular Ca ion. It is possible that reduction of intracellular Ca ion suppressed the desensitization.

Influence of follicle-stimulating hormone on glucose transport by cultured Sertoli cells

Transport of 3-O-methyl-D-[14C]glucose by Sertoli cells cultured in plastic dishes, is competitively inhibited by glucose (Ki 4 microM). The glucose analogue was therefore used to study glucose transport in these cells in which it is not metabolized. Addition of follicle-stimulating hormone (FSH) (10 micrograms/ml) or dibutyryl cyclic AMP (1 mM) to the cells, increases transport of methylglucose by Sertoli cells. The increased transport results from increased influx and involves decrease in Km without change in Vmax. These changes in the kinetics of transport are seen with both FSH and dibutyryl cyclic AMP. FSH does not stimulate transport of methylglucose in peritubular fibroblasts nor in germ cells. In view of the importance of lactate as a substrate for spermatids (Mita and Hall, 1982) it is proposed that stimulation of the transport of glucose by Sertoli cells in response to FSH is important in the increased production of lactate by these cells in response to FSH and hence is one mechanism by which the tropic hormone enables the Sertoli cell to promote spermatogenesis.

Activation of respiration in sea urchin spermatozoa by calcium ionophore A23187

The respiratory rate in spermatozoa of the sea urchin, Hemicentrotus pulcherrimus, in Na+-free seawater, where sperm are immotile and their respiration remains inactive, was stimulated by calcium ionophore A23187. Addition of ionophore A23187 to Na+-free seawater induced swimming as well as activating energy metabolism in sea urchin sperm. The increase of respiratory rate and the initiation of motility in sperm were independent of external Ca2+.

The actions of insulin-like growth factors I and II on cultured Sertoli cells

Cultured Sertoli cells prepared from young rats (13 days old) showed increased incorporation of [3H]thymidine into DNA, increased production of lactate, and increased incorporation of [3H]leucine into protein in response to micromolar concentrations of insulin and nanomolar concentrations of insulin-like growth factor II (IGF-II). The first of these responses was also seen with nanomolar concentrations of IGF-I. Receptor affinity labeling studies using Sertoli cell membranes and whole Sertoli cells showed that these cells possess abundant growth factor receptors of type I (mol wt, 350,000) that show high affinity for IGF-I, moderate affinity for IGF-II, and low affinity for insulin. Sertoli cell membranes also show abundant growth factor receptors of type II (mol wt, 230,000) that show high affinity for IGF-II, moderate affinity for IGF-I, and no detectable affinity for insulin. Moreover, the responses of the Sertoli cell to insulin were observed at concentrations of 100 nM or higher, whereas insulin receptors are known to be saturated by insulin at concentrations of 10 nM or less. It is, therefore, concluded that Sertoli cells possess receptors for IGF-I and that the responses observed to insulin may result from binding of these hormones to receptors for IGF-I.

Effect of polyamines on palmitoyl-coenzyme A-caused inhibition of glucose-6-phosphate dehydrogenase from baker's yeast

Aliphatic polyamines reversed the inhibition of baker's yeast glucose-6-phosphate dehydrogenase by palmitoyl-CoA. The reversal effects of the polyamines on the inhibition were related not only to the number of amino (imino) groups but also to the carbon chain length of polyamine. The relieving constant (Kr) was calculated to determine the absolute concentration of each examined polyamine required to relieve the enzyme from the inhibition. A smaller Kr value indicates a stronger relieving activity. An ethylamine derivative with a large number of amino groups was more effective in reversing the palmitoyl-CoA inhibition. The Kr values of long-chain aliphatic diamines, triamines, and tetramines were smaller than those of short-chain ones. However, n-butylamine and ornithine, composed of four carbons like putrescine, had markedly larger Kr values than putrescine. Substitution of one or two amino groups by carboxyl or hydroxyl groups also appeared to relieve the enzyme from the inhibition. These results suggest that the reversal effect on palmitoyl-CoA inhibition is one of the important roles of polyamines. Furthermore, it is possible that the interaction of palmitoyl-CoA and polyamines physiologically regulates the pentose monophosphate cycle in baker's yeast.

Regulation of the tricarboxylic acid cycle in sea urchin eggs and embryos

Contents of the tricarboxylic acid (TCA) cycle intermediates, coenzyme A (CoA) derivatives, and carnitine derivatives were estimated in the developing eggs and embryos of the sea urchin, Anthocidaris crassispina. Levels of the TCA cycle intermediates in unfertilized eggs were similar. The level of malate increased remarkably after fertilization and reached a plateau just before hatching out. Slight elevation in the level of citrate was also observed during early development. These suggest that metabolism of citrate and malate is altered during development. Long-chain fatty acyl-CoA was accumulated in unfertilized eggs. Its level decreased after fertilization, then gradually increased until the late gastrula stage and turned to decline. Free CoA level increased after fertilization and reached a peak around the gastrula stage, and thereafter it decreased, while short-chain acyl-CoA level decreased gradually after fertilization. Crude citrate synthase from sea urchin unfertilized and fertilized eggs was inhibited by palmitoyl-CoA, though malate dehydrogenase was not inhibited. The palmitoyl-CoA-caused inhibition of citrate synthase was also relieved by spermine and spermidine. In view of the inhibition of citrate synthase by palmitoyl-CoA at concentrations in unfertilized eggs, the enzyme is probably inhibited in unfertilized eggs by long-chain acyl-CoA and released from the inhibited state by the decrease in the level of long-chain acyl-CoA and the increase in the level of polyamines following fertilization.

Stimulation by follicle-stimulating hormone of synthesis of lactate by Sertoli cells from rat testis

Sertoli cells from rats aged 16 days were cultured in defined medium for 2 days and then treated by addition of fresh medium containing various hormones (treated) or saline (control). The concentration of lactate in the medium was measured as a function of time. The production of lactate measured under these conditions was increased by addition of FSH to the medium. For NIH FSH (13 and 14), ED50 for stimulation of lactate production was approximately 0.05 micrograms/ml. Stimulation was also seen with LH and TSH (ED50, 0.8 micrograms/ml for both hormones). Reasons are given for believing that TSH may possess the inherent capacity to stimulate production of lactate in contrast to LH, which appears to act only by way of contaminating traces of FSH. Dibutyryl cAMP also stimulates lactate production by Sertoli cells. Other hormones tested, including androgens, were without effect. When production of lactate by Sertoli cells was compared with the maximal consumption by spermatids in vitro, it became apparent that Sertoli cells may provide the major source of metabolic substrate for spermatids in the form of lactate. Stimulation of lactate production by FSH was inhibited by puromycin, cycloheximide, and actinomycin D. Evidently this response requires synthesis of new protein and RNA. This effect of FSH may be important in the regulation of spermatogenesis.

Metabolism of round spermatids from rats: lactate as the preferred substrate

Round spermatids were prepared from rat testes and incubated with various substrates (glucose, fructose, pyruvate, lactate and acetate) to measure utilization of substrates and production of ATP in the presence of saturating levels of each substrate. By both criteria lactate is the preferred substrate by a factor of 3 or 4. Production of more than half of the ATP with lactate is substrate is prevented by addition of an inhibitor of alpha-ketoacid dehydrogenase (5-methoxyindole-2-carboxylic acid) Pyruvate and lactate are interconverted and pyruvate inhibits production of ATP from lactate. Synthesis of ATP with lactate and with pyruvate is inhibited by rotenone, rutamycin or 2,4-dinitrophenol. Utilization of glucose is limited by aldolase activity. These findings suggest that exogenous lactate is oxidized by lactate dehydrogenase followed by pyruvate dehydrogenase and Krebs; cycle enzymes under conditions which do not allow pyruvate to inhibit lactate dehydrogenase. ATP is synthesized through electron transport. Post-mitochondrial supernate from spermatids showed that high concentration of pyruvate (greater than 1 mM) inhibit lactate dehydrogenase with pyruvate as substrate and that with lactate as substrate, pyruvate behaves as a competitive inhibitor of lactate dehydrogenase. Evidently lactate is the preferred substrate for round spermatids and energy production is most efficient when this substance is present in high concentrations and pyruvate is present in low concentrations. Reasons are given for suggesting that Sertoli cells may provide the relatively large amounts of lactate required by round spermatids.

Mechanism of coenzyme A inhibition of dihydrofolate reductase

1. Coenzyme A was found to inhibit bovine liver dihydrofolate reductase. 2. The CoA inhibition types of dihydrofolate reductase were competitive with respect to NADPH and noncompetitive with respect to dihydrofolate. 3. The CoA inhibition is related to the number and the site of phosphoric residue in adenine nucleotide.

[Clinical evaluation of cefotiam in internal medicine, with special reference to infectious disease associated with hematological disorders (author's transl)]

Clinical evaluation of cefotiam (panspolin), a new cephem antibiotics, was performed in the infectious disease associated with hematological disorders and in the respiratory system. In hematological dis orders, 40% of good and 25% of fair results were obtained in clinical effects. In respiratory infections, however, 92% of good results were obtained. Opportunistic infection due to Gram-negative bacilli are often experienced in patients with leukemia. Since cefotiam has sufficient bacteriocidal effects in broad spectrum, it would be a good therapeutic agent against infectious diseases associated with hematological disorders.

Mucosal secretion of the duodenum in peptic ulcer disease

Mucosal secretin content of the duodenum was measured using bioptic specimen in healthy controls and patients of peptic ulcer. Immunoreactive secretin in the duodenal mucosa was found greater in healthy controls (7.73 +/- 2.71 ng/mg dry wt., mean +/- S.D.) than in gastric ulcer patients (5.76 +/- 3.51 ng/mg dry wt.) and duodenal ulcer patients (5.54 +/- 2.48 ng/mg dry wt.), but the difference was not significant. There was no significant relationship between mucosal secretin and acid output in these patients.

Secretin-like bioactivity in the duodenal mucosa in patients with peptic ulcer and chronic pancreatitis

Biopsy specimens of the duodenal mucosa were assayed to determine their secretin-like activity in 9 controls, 9 patients with gastric ulcer, 19 patients with duodenal ulcer, 4 patients with gastric and duodenal ulcer, and 13 patients with chronic pancreatitis. The bioassay of secretin was done on the pancreatic secretion in anesthetized rats. The sensitivity was in the orcer of 0.0625 CHR unit/rat (4 ng/rat). In the range between 0.0625 and 0.5 CHR units a satisfactory dose dependency was recognized. The following results were obtained. 1) The level of duodenal mucosal secretin-like activity in patients with gastric ulcer was the same as that in the controls, but was elevated in 32% of the patients with duodenal ulcer, 50% of those with gastric and duodenal ulcer, and 8% of those with chronic pancreatitis. 2) The high level of secretin-like activity noted in patients with duodenal ulcer was suspected to be related to the hypersecretion of gastric acid which is characteristic of this disease, but there was no correlation between gastric acid secretion and secretin-like activity in the duodenal mucosa.

A new fiberintestinoscope type FIS-T1 patterned after intestinal biopsy tube

A new type of fiberintestinoscope (FIS-T1) patterned after an intestinal biopsy tube was developed for observing the small intestine beyond the ligament of Treitz. The flexible part of the new FIS has been made as pliable as the Cantor tube or the Miller-Abbott tube so that the tip of the new FIS is carried on into the small intestine by peristaltic activity along its natural configuration. A balloon attached near the tip of the new FIS acted as a bolus, enabling peristaltic activity to carry the fiberscope to the distal portion. In order to facilitate the passage of the fiberscope, it was also advisable to keep changing the posture and position of the body with a minimum of fluoroscopic exposure. Inflation of the balloon as well as air feeding through the air channel of the fiberscope made possible satisfactory observation. In a patient suffering from protein-losing gastroenteropathy, multiple white spots on the diffuse rough surface of the mucosa were visualized by using the new FIS. Histological finding of the biopsy specimen taken from near the ligament of Treitz by using the fiberduodenoscope showed dilated lymph vessels in the villi.