Weak binding of 10-hydroxymetabolites of nortriptyline to rat brain muscarinic acetylcholine receptors

The relative affinities of nortriptyline (NT) and its 10-hydroxymetabolites to rat brain muscarinic acetylcholine receptors have been determined by competition with 3H-quinuclidinyl benzilate binding. It is shown that the major NT metabolite, E-10-OH-NT, has only 1/18 the affinity of NT for the muscarinic receptor. Since this metabolite is equipotent to NT in inhibiting neuronal noradrenaline uptake, it is suggested that it might be of clinical value as an antidepressant by virtue of having less anticholinergic side-effects than NT itself.     

Extraction of estrogens by the hind limb of the dog. Evidence for entry into the lymphatics.

Substantial extrasplanchnic metabolism of estrogens is known to occur in humans and dogs. As part of an investigation into the anatomic sites of such metabolism, the extraction of estrogens by the hind limb of the dog was studied during a constant infusion of [³H]estrone. Simultaneous femoral artery (A) and femoral vein (FV) plasma samples were obtained and analyzed for total radioactivity, unconjugated and conjugated radioactivity, for [³H]estrone and for its metabolites estradiol-17β, estrone sulfate and estrone glucosiduronate. The percent extraction across the hind limb was calculated [100(1-FV/A)]. The mean percent extraction ± SE of total, conjugated and unconjugated radioactivity was 31 ± 3.9, 27 ± 4.4 and 16 ± 3.7 respectively, indicating significant net uptake of these moieties by the hind limb (P<.01). Mean percent extractions ± SE for estrone and estradiol-17β were 40 ± 4.9 and 32 ± 2.7, indicating significant net uptake of these specific unconjugated estrogens by the hind limb (P<.01). The mean percent extraction of estrone glucosiduronate was 16 ± 3.1 indicating significant net uptake of this conjugate (P<.01). However, the mean percent extraction of estrone sulfate was negative (?12 ± 4.1) indicating net production of this conjugate by the hind limb (P<.01). Since the net uptake of total radioactivity cannot be explained on the basis of metabolism by the hind limb, the lymphatics were investigated as an alternate efferent pathway. In similar experiments the thoracic duct was cannulated, the estrogens in lymph were analyzed and compared with those in femoral artery plasma. Each estrogen measured in plasma appeared in lymph within 10 minutes following the start of the [³H]estrone infusion. The lymph/femoral artery concentration ratios reached a plateau at 70–100 minutes after the start of the infusion. The plateau concentrations were 20–70% of those in plasma. It is suggested that removal of estrogens in the lymph may account, in part at least, for the net uptake of total radioactivity across the hind limb calculated from the plasma data.     

Radioimmunoassay of androsterone and androsterone-3-sulfate in plasma

Details of a sensitive and specific radioimmunoassay for androsterone (1) and androsterone sulfate in plasma have been presented. Benzene extracts of plasma were chromatographed on a lumina to isolate the androsterone fraction either (a) directly after extraction (A) or (b) after solvolysis (AS). Following treatment with rabbit anti-A-17-BSA, antibody bound steroid was precipitated by ammonium sulfate. Androsterone concentrations in normal male plasma averaged 57 ± 24 (S.D.) ng/dl, range 35–135 ng/dl and for normal women, 44 ± 21 (S.D.) ng/dl, range 18–98 ng/dl. Androsterone sulfate concentrations were: males 55 ± 28 μg/dl (range 10–114 μg/dl); premenopausal females 52 ± 31 μg/dl (range 16–318 μg/dl).     

Radioimmunoassay for etiocholanolone

A sensitive and reliable radioiinmunoassay for serum unconjugated etiocholanolone (3α-hydroxy-5β-androstan-17-one) is reported. The antiserum was obtained from rabbits by immunization of etiocholanolone-17-(O-carboxy-methyl) oxime [CMO] -bovine serum albumin [BSA]. Two ml of serum with ³H-etiocholanolone added for recovery was extracted with ether, and etiocholanolone was separated from cross-reacting steroids by Sephadex LH-20 column chromatography.The mean recovery after extraction and chromatography was 80.7 ± 6.8(S.D.)%. The sensitivity of the assay was less than 40 pg. The intraassay and interassay coefficients of variation were 9.2% and 10.9%, respectively. The mean of serum unconjugated etiocholanolone concentration determined by the present method was 0.39 ± 0.10 (S.D.) ng/ml (n = 50) in normal men and 0.36 ± 0.08 (S.D.) ng/ml (n = 20) in women in the follicular phase of the menstrual cycle.     

Simultaneous radioimmunoassay of 5α-amdrostane-3α, 17β-diol and 5α-androstane-3β, 17β-diol unconjugated and conjugated in human serum

The simultaneous determinations of both 3α and 3β epimers of 5α-androstane-3, l7β-diol as their glucuronides, sulfates and in their unconjugated forms are described. The diol estimation is carried out by radioimmunoassay with two specific immune sera after purification of the serum by use of chromatography on Sephadex LH-20. The values obtained (mean ± S.D.) in pg/ml for the unconjugated 3α and 3β epimers were, respectively, 267 ± 67 and 816 ± 76 for men; 114 ± 33 and 515 ± 177 for women; 142 ± 77 and 779 ± 200 for hirsute women. Among the conjugates, the most important were the sulfoconjugates, their rates being, respectively, (men ± S.D. in ng/ml) 41.3 ± 9.5 and 103 ± 40 for men; 12.4 ± 3.1 and 51.2 ± 14.9 for women and 36 ± 22 and 72 ± 36 for hirsute women. Differences in the conjugation of both epimers were also noticed.     

Potassium uptake by platelets from Down's syndrome and normal subjects

Potassium uptake was studied in Down's syndrome (D.S.) platelets to determine if the Na⁺/K⁺ ATPase mediated movement of this ion was decreased compared to normal platelets. Total uptake of ⁴²K was 1.58±0.16 μmoles/hr/10⁹ normal platelets but was decreased to 1.06±0.06 μmoles/hr/10⁹ D.S. platelets (p<.001). Na⁺/K⁺ ATPase mediated (ouabain sensitive) K⁺ uptake was 0.87±0.05 μmoles/hr/10⁹ normal platelets but only 0.54±0.04 μmoles/hr/10⁹ in D.S. platelets (p<.001). As the Na⁺/K⁺ ATPase mediated outward movement of Na⁺ is decreased in D.S. platelets, the present work demonstrates that bidirectional functional imparrment of the Na⁺/K⁺ ATPase pump is present in D.S. platelets.     

The influence of allyl trenbolone (Regumate) on the timing,duration and endocrinology of parturition in sows

A study was undertaken to evaluate the effects of using an oral progestagen for synchronisation of parturition in the sow. Multiparous Landrace X Large White sows were fed 20 mg allyl trenbolone daily from day 110 to 115 of gestation then 15 mg on day 116 (Group R; N = 12); untreated sows of similar background served as controls (Group C; N = 9). Blood samples, taken at 8-h intervals from day 110 of gestation to onset of parturition, then every 4 h until parturition was complete, were assayed for plasma levels of progesterone, unconjugated oestrone, cortisol and prolactin. Duration of farrowing, incidence of stillbirths and individual piglet birth weights were recorded. Five Group R sows farrowed during the period of progestagen administration, while for the remaining 7, the mean interval from last progestagen treatment to emergence of first piglet was 31.6 ±5.5 h. Gestation length, duration of parturition, and mean interval between successive births all were longer in Group R than in Group C (116.5 ± 0.34 compared with 115.0 ± 0.52 days, P < 0.01; 9.73 ± 1.98 compared with 3.08 ± 0.70 h, P < 0.01; and 53.4 ± 10.2 compared with 16.2 ± 2.4 min., P < 0.01, respectively). No significant treatment differences were apparent for litter size at birth, proportion stillborn or piglet birth weights. Profile analysis showed that plasma progesterone levels in Group R were lower (P < 0.05) during the 30 h prefarrowing, suggesting a longer mean interval between functional luteolysis and parturition in these animals. In both Groups plasma levels of unconjugated oestrone rose in the prefarrowing period, the levels being higher (P < 0.05) in Group R Peak oestrone levels occurred at the commencement of, and had declined to low levels by the completion of, farrowing. Cortisol levels exhibited a pattern similar to that of oestrone, although peak levels at parturition were lower in Group R (P < 0.01). Plasma prolactin levels in the 24 h prepartum rose faster and reached higher levels (P < 0.05) in Group C than Group R, but the difference was no longer apparent subsequent to first piglet emergence. It is concluded that the use of this progestagen to delay parturition upset the synchronisation of endocrine events at farrowing, resulting in an increased duration of parturition.     

Measurement of thromboxane B2 in human plasma or serum by radioimmunoassay

A radioimmunoassay for thromboxane B₂ (TxB₂), a stable metabolite of thromboxane A₂, is described. The method consists of extraction of TxB₂ into ethyl acetate from acidified plasma or serum samples and saturation analysis using specific antibodies produced in rabbits against TxB₂-BSA conjugate. The 50 % displacement level of the standard curve was 19.1 ± 2.9 pg/tube (mean ± S.D., n = 19). The method blank was 3.4 ± 3.1 pg/ml (n = 15) and the assay sensitivity thus 9.6 pg/ml (mean blank + 2 S.D.). When 100 to 200 pg of TxB₂ were added to plasma, 96.2–103.6 % were recovered. The intra-assay coefficient of variation varied from 6.7 to 9.7 %, and the inter-assay coefficient of variation was 18.6 % (n = 10). The TxB₂ concentration in the plasma of 14 healthy subjects varied from 29.3 to 120.8 pg/ml with a mean ± S.D. of 70.1 ± 26.1 pg/ml, when the blood was collected into tubes containing acetylsalicylic acid (ASA), whereas significantly higher (p < 0.001) TxB₂ concentrations of 68.3 – 285.3 pg/ml with a mean ± S.D. of 151.8 ± 66.6 pg/ml were obtained from the same subjects in the plasma of blood which was collected into tubes containing no ASA. When blood samples from 10 subjects were allowed to clot at 0, +24 or +37°C for 60 min., the TxB₂ concentrations in the sera were 2053 ± 870 pg/ml, 4001 ± 1370 pg/ml and 178557 ± 54000 pg/ml, respectively. The TxB₂ levels in sera which were separated from blood samples incubated at +37°C, correlated significantly (p < 0.001) with the TxB₂ productions in platelet-rich-plasma (PRP) after an induced aggregation. Our results indicate 1) when TxB₂ is measured in plasma, the use of prostaglandin synthesis inhibitor in the collection tubes is necessary and 2) the measurement of TxB₂ in serum of blood which has been kept at +37°C for a strictly standardized period of time could replace the use of PRP in TxB₂ studies.     

Uptake and effects of ovarian steroids in the early pig embryo: In vitro and in vivo studies

The role of ovarian steroids in the preimplantation pig embryo was studied in vivo and in vitro. Twenty gilts were treated three times daily on days 1 to 4 after insemination with either 25, 100, 250, or 1000 mg progesterone in oil, and 17 gilts were injected with corresponding amounts of sesame oil (controls). All gilts were slaughtered 5 days after insemination and the embryos were recovered. Oviduct and plasma progesterone content were significantly (P<0.001) higher in gilts treated with 750 mg of exogenous progesterone per day. After 750 mg progesterone, oviduct progesterone content was twice as high as control levels, while after 3000 mg progesterone per day the levels in oviduct and uterus exceeded those of controls by five and seven times, respectively. In gilts treated with 750 mg progesterone per day, plasma progesterone levels were 177.4 ± 22.1 ng/ml ($\text{x}\text{±}\text{SD}$) on day 3 and 186.4 ± 69.2 ng/ml on day 5 and resembled values found in superovulated pigs with more than 40 ovulations. Excessive plasma progesterone values of 1014.6 ± 840.4 ng/ml on day 3 and 473.2 ± 197.2 ng/ml on day 5 were found after treatment with 3000 mg of progesterone per day. Treatment with up to 750 mg of exogenous progesterone per day, did not affect embryonic development, but 3000 mg per day resulted in a significantly (P<0.001) higher percentage of retarded and degenerate embryos compared to controls (71.8% versus 3.2%).In addition, the amount and specificity of uptake of ³H-labelled progesterone and estradiol-17 beta by pig blastocysts recovered from superovulated gilts were investigated after 6 hrs in vitro culture. The uptake of ³H-progesterone was 131.9 ± 56.9 counts per million (cpm) per 10 blastocysts, corresponding to 1.1 fmoles progesterone. The uptake was non-specific for it was only slightly reduced in the presence of a 100-fold excess of unlabelled progesterone (20.1%) or estradiol-17 beta (27.0%). The uptake of ³H-estradiol-17 beta was 133.9 ± 74.12 cpm per 10 blastocysts, corresponding to 1.3 fmoles estradiol-17 beta. The uptake was significantly (P<0.01) reduced by 67.7% in the presence of a 100-fold excess of unlabelled estradiol-17 beta. Apparent specific binding was 0.87 fmoles estradiol-17 beta per 10 blastocysts or 72.5 fmoles estradiol-17 beta per mg protein. The uptake was only slightly reduced in the presence of a 100-fold excess of unlabelled progesterone (23.3%). This significant inhibition could be determined after 2 hrs in vitro culture. There was no competitive inhibition after 20 min. of culture.Uptake by unfertilized ova and degenerate embryos recovered on day 5 was significantly smaller (51.8 ± 10.3 cpm per 10 eggs; P<0.001) than by blastocysts recovered on the same day. No competitive inhibition could then be determined. In vivo, preimplantation pig embryos seem to be rather insensitive to high progesterone levels. Excessive amounts of progesterone probably can be metabolized to a great extent. Progesterone seems to be taken up rather non-specifically by the pig embryo. The uptake and binding of estradiol-17 beta seems to be more specific. Studies are in progress to investigate the physiological role of estradiol-17 beta uptake in early embryonic development.     

Simultaneous determination of phospholipid hydroperoxides and cholesteryl ester hydroperoxides in human plasma by high-performance liquid chromatography with chemiluminescence detection

A method was developed for the simultaneous determination of phosphatidylcholine hydroperoxides (PCOOH) and cholesteryl ester hydroperoxides (CEOOH). Lipid hydroperoxides (LOOH) were quantitatively extracted from human plasma with a mixture of n-hexane and ethyl acetate, and separated by column-switching high-performance liquid chromatography using one aminopropyl column and two octyl columns followed by chemiluminescence detection. LOOHs could be completely separated from each other and detected at picomole levels. The results of method validation tests were satisfactory. This method was then applied to determine LOOH in normal human plasma; the levels of PCOOH and CEOOH found were 36.0±4.0 nM (mean±S.D., n=6) and 12.3±3.1 nM (mean±S.D., n=6), respectively.     

Soluble CD23 in Human Immunodeficiency Virus Type 1 Infected Patients

The level of sCD23 produced in the course of human immunodeficiency virus (HIV) infection was measured in patients grouped according to the Centers for Disease Control by using an immunoradiometric assay. Soluble CD23 was evaluated in supernatants of peripheral blood mononuclear cell (PBMC) (10⁶ cells/ml) stimulated by phytohemagglutinin (PHA). Compared with healthy controls (m±S.D. = 1.0 ±0.34 U/ml, n = 7), higher values were observed in some of the patients of group II (asymptomatic) (m±S.D. = 2±1.33, n = 9) and some of the patients of group IV (AIDS) (m±S.D. = 1.3 ±1.40, n = 8). Those results prompted us to compare the plasma levels of sCD23 in group II and group IV HIV-infected patients and in healthy individuals. Soluble CD23 plasma levels in healthy patients (n = 42) ranged from 0 to 1.5 U/ml (m±S.D. = 0.9±0.33), in group II patients (n = 17) from 0 to 3 U/ml (m±S.D. = 0.92±0.83) and in group IV patients (n =73) from 0 to 2.9 U/ml (m±S.D. = 1.15±0.71). The differences between the patients and the healthy individuals were not statistically significant but individual sCD23 values higher than 2 U/ml were obtained in 6% of the group II patients and 16.7% of the group IV patients. Increased values of sCD23 were obtained in plasma from patients with secondary infectious diseases (groups IV-C1 and IV-C2) and from patients without secondary infectious diseases (group II, group IV-A and group IV-B). Elevated values of sCD23 were detected even in patients with low counts of CD4⁺ T cells and CD8⁺ T cells in their peripheral blood. sCD23 has numerous activities including control of IgE synthesis and cytokine-like properties. Our results show a disarray of sCD23 in HIV-infected patients which could be involved in drug reactions, allergic manifestations and the IgE-level increase. Further investigations should attempt to define the role of sCD23 in clinical manifestations of HIV infection.     

Increased glucose production following neurotensin administration

Neurotensin (NT), a recently isolated extract from bovine hypothalami, has been shown to have a hyperglycemic effect when injected into fed rats. This hyperglycemia has been attributed entirely to glycogenolysis, but no evidence is available regarding the effect of NT on the rate of glucose production and uptake. We have therefore used the primed-constant infusion of 6-³H-glucose technique to evaluate the effect of an intravenous injection of NT (1.2 nmole/kg) on glucose production $\text{in vivo}$ in 48-h starvèd, conscious rats (n=10). NT induced a progressive rise in plasma glucose concentration from the control value of 101 ± 2.3 to 162.2 ± 10.8 mg/dl at 30 min. Glucose production was significantly (p<.05) elevated 35–40% throughout the first 30 minutes after NT, while the rate of disappearance of glucose was slightly, but not significantly, elevated. An average of 38.2 mg/animal of glucose was required to account for the average increase in glucose production above the basal rate during the 30 minutes following NT. This requirement exceeded the total amount of glycogen (27.9 mg.) found in the livers of 48 hour starved rats. We therefore concluded that the rise in blood glucose concentration after NT injection was entirely due to an increased rate of glucose production, and that at least part of the increased glucose production represented an elevated rate of gluconeogenesis.     

Determination of the antihypertensive agent 1-(2-aminoethyl)-3-(2,6-Dichlorophenyl)thiourea in plasma and urine by high-performance liquid chromatography

A rapid, sensitive and specific normal-phase (adsorption) high-performance liquid chromatographic (HPLC) assay was developed for the determination of 1-(2-aminoethyl)-3-(2,6-dichlorophenyl)thiourea [I] in plasma and urine. The assay involves the extraction of the compound into methylene chloride from plasma or urine buffered to pH 10, and the HPLC analysis of the residue dissolved in methylene chloride—methanol—heptane (85:10:5). A 10-μm silica gel column was used with methylene chloride—methanol—heptane—ammonium hydroxide (85:10:5:0.1) as the eluting solvent. The effluent was monitored at 254 nm and quantitation was based on the peak height vs. concentration technique. The assay has a recovery of 64.5 ± 4.5% (S.D.) from plasma and 96.0 ± 6.3% (S.D.) from urine in the concentration range of 0.1–2 μg per ml and 2–40 μg per 0.1 ml of plasma and urine, respectively, with a limit of detection of 0.05–0.1 μg [I] per ml of plasma using a 1-ml specimen and 0.1 μg per ml urine using a 0.1-ml specimen, respectively. The assay was applied to the determination of plasma levels and urinary excretion of the compound [I] in dog following the oral administration of 28.8 mg of [I] · maleate per kg body weight.The HPLC assay was also used to determine the stability of [I] and for the measurement of a potential degradation product, clonidine [II] [2-(2,6-dichlorophenylamino)-2-imidazoline] in pooled human plasma stored at ?17°C, and pooled human urine stored at ?17°C and ?90°C, respectively.     

Effect of Gastric Banding on Aminoterminal Pro‐brain Natriuretic Peptide in the Morbidly Obese

Objective: Aminoterminal pro‐brain natriuretic peptide (NT‐proBNP), like brain natriuretic peptide, might have diagnostic utility in detecting left ventricular hypertrophy and/or left ventricular dysfunction. The aim of the study was to investigate the relationship between morbid obesity and NT‐proBNP and the effect of weight reduction on this parameter. Research Methods and Procedures: A total of 34 morbidly obese patients underwent laparoscopic adjustable gastric banding (LAGB). NT‐proBNP levels were measured before and 12 months after the surgery. Results: Metabolic features and systolic and diastolic blood pressure were significantly decreased (p < 0.00001 for both) after a cumulative weight loss of 19.55 kg 1 year after LAGB. NT‐proBNP concentration was significantly higher in morbidly obese patients before LAGB than in normal‐weight control subjects (341.15 ± 127.78 fmol/mL vs. 161.68 ± 75.78 fmol/mL; p < 0.00001). After bariatric surgery, NT‐proBNP concentration decreased significantly from 341.15 ± 127.78 fmol/mL to 204.87 ± 59.84 fmol/mL (p < 0.00, 001) and remained statistically significantly elevated (204.88 ± 59.84 fmol/mL vs. 161.68 ± 75.78 fmol/mL; p = 0.04) compared with normal‐weight subjects. Discussion: This investigation demonstrates higher levels of NT‐proBNP in morbidly obese subjects and a significant decrease during weight loss after laparoscopic adjustable gastric banding. In obesity, NT‐proBNP might be useful as a routine screening method for identifying left ventricular hypertrophy and/or left ventricular dysfunction.     

Determination of amitriptyline and nortriptyline in human plasma by quantitative thin-layer chromatography

A thin-layer chromatographic method for simultaneous determination of amitriptyline (AT) and nortriptyline (NT) in human plasma is described. Both substances are extracted from biological material by means of a single extraction. The extract is evaporated until dry and the residue quantitatively applied to a silica gel thin-layer plate. AT and NT are separated from interfering plasma components by chromatography. The spots are visualized by nitration, reduction and coupling with N-(1-naphtyl)ethylenediamine on the plate. The intensity of the azo-dyes formed can be measured densitometrically. Using 1 ml of plasma, the sensitivity limit was 0.5 ng/ml for both substances. About 10–15 plasma samples can be analysed per day. The method is applicable to pharmacokinetic studies after a single oral dose of 25 mg AT as hydrochloride in man.     

A primary culture system of adult rat heart cells for the study of toxicologic agents

Summary Tricyclic antidepressants (TCAs) are currently used in the treatment of mental depression and nocturnal enuresis. Clinically, these drugs are useful; however, cardiotoxicity can occur even with therapeutic dosages. For example, TCAs are known to alter myocardial function, induce arrhythmias, and produce heart block in individuals with a normal cardiovascular history. The present study was undertaken to establish a culture system of spontaneously contracting adult primary myocardial cells for toxicologic testing and to examine their contractility, morphology, and lactate dehydrogenase release (LDH) after treatment with one of the most cardiotoxic TCAs, amitriptyline. Primary myocardial cell cultures were obtained from approximately 60- to 90-day-old Sprague-Dawley rats. After the cells had been grown in culture for 11 days, they were treated with amitriptyline (1 × 10⁻³, 1 × 10⁻⁴, and 1 × 10⁻⁵ M) for 2 to 24 h. The highest concentration of amitriptyline (1 × 10⁻³ M) completely destroyed the cardiac muscle cells. In addition to moderate and severe vacuole, granule, and pseudopodia formation, all contractile activity was inhibited as early as 2 h after exposure to the intermediate concentration of 1 × 10⁻⁴ M amitriptyline. Significant LDH release did not occur until 8 h after treatment with this intermediate concentration. Even though there was no significant LDH release at all 3 time points tested, there was a 50% decrease in beating activity (154±9 to 77±5 beats/min) and initiation of vacuole formation by 2 h with the lowest concentration of amitriptyline (1 × 10⁻⁵ M). This study presents a new apparatus for the isolation of adult cardiac myocytes for the establishment of primary cell cultures for toxicologic testing. Furthermore, these data demonstrate that amitriptyline induces a concentration- and time-dependent cardiotoxic profile in a model of spontaneously contracting adult cardiac muscle cells in culture.     

Radioimmunoassay of plasma androsterone

A method is described and evaluated for the determination of androsterone in peripheral venous plasma (1.0 ml) from men and women. The procedure involves addition of labelled internal standard and extraction with diethyl ether. Aliquots (10 %) are removed for radioimmunoassay. An antiserum to androsterone-17-carboxymethyl oxime-bovine serum albumin and tritiated androsterone complete the system. The practical systematic errors have been determined by replicate analyses. The range of values (mean ± S.D.) in plasma from 40 healthy men are 54 ± 32 ng/100 ml, and the corresponding values for women 46 ± 28.     

Prostaglandin F2α concentration in genital tract secretions of dairy bulls

Prostaglandin F_2α (PGF_2α) concentrations in genital tract secretions of conscious dairy bulls were determined by radioimmunoassay procedures and compared with peripheral blood plasma levels. The mean (± SD) PGF_2α concentration of coccygeal venous blood plasma from four bulls was 0.14 ± 0.05 ng/ml. Values for rete testis fluid and seminal plasma were the same, namely 0.17 ± 0.01 ng/ml (n = 5) and 0.17 ± 0.02 ng/ml (n = 4), respectively. However, the PGF_2α level in cauda epididymal plasma was 1.61 ± 0.41 ng/ml, or over 8 to 10 times (P < 0.01) the concentration of any other fluid studied.Added PGF_2α had no effect on the endogenous oxygen consumption of washed cauda epididymal spermatozoa or on the oxidative and glycolytic activities of washed ejaculated spermatozoa in vitro. No evidence was obtained suggesting that the prostaglandin may interact with the stimulatory effect of added testosterone or phosphatidylinositol (PI) on the motility, respiration or glucose uptake of ejaculated spermatozoa.     

Blood volume inMacaca fascicularis

The plasma and erythrocyte volumes ofMacaca fascicularis were determined using blood labelled with¹²⁵I-serum albumin and⁵¹Cr. It was found that the erythrocyte, plasma and packed cell volumes were 108±6 ml (Mean±S.D.), 210±10 ml and 37±2%, respectively. Total blood volume of macaque was 8% of body weight.     

Regulation of trehalose metabolism by Adox and AdoMet in Saccharomyces cerevisiae

Effect of a potent methylation inhibitor oxidized adenosine (Adox), and a universal methyl group donor S-adenosyl-L-methionine (AdoMet) on trehalose metabolism was studied in two haploids of S. cerevisiae of mating types MATalpha, met3 (6460 -8D) and MATa, leu2, ura3, his4 (8534 -10A). Trehalose level decreased in presence of Adox in both strains. Both neutral trehalase (NT) and trehalose-6-phosphate (tre-6-p) synthase activities increased in presence of Adox in -8D strain. Decrease in trehalose level in -8D thus could not be explained in the light of increased tre-6-p synthase activity; however, it could be correlated with increased NT activity. In strain -10A, NT activity was reduced in presence of Adox while tre-6-p synthase activity increased. Enzyme activity profiles in -10A thus do not explain the reduced trehalose level on Adox treatment. Effect of AdoMet was not very prominent in either strain, though in -8D a small increase in trehalose level was seen on treatment. Intracellular AdoMet level of untreated cells of -10A was seen to be almost six times higher than that of -8D. Further, AdoMet treatment caused increase in its level compared to untreated cells, suggesting AdoMet uptake. No effect of either compound was seen on acid trehalase (AT) activity in any strain. The results suggest that there was a possible effect of demethylation on trehalose metabolism (particularly in the synthetic direction) in both strains, though effect of methylation was not very prominent, the reason for which is not very clear.