The effect of anesthetics on the basal secretion of immunoreactive growth hormone in rats]

The authors investigated basal levels of plasma immunoreactive growth-hormone in the rat (R-GH) after administration of 3 different anesthetic drugs: urethan, chloral hydrate and gamma-hdroxy-butyrate (GHB). Lowest R-GH concentrations (5 +/- 3 ng/ml) are observed after urethan; they are significantly higher (15 +/- 4 ng/ml) after chloral hydrate but this anesthetic also causes hyperglycemia (210 +/- 30 mg/100 ml). Normal blood glucose levels are observed under GHB narco-analgesia which elicits a clear-cut R-GH secretory episode (70 +/- 5 ng/ml); basal values (12 +/- 3 ng/ml) are maintained for several hours thereafter.     

Hormonal facilitation in the release of sperm from the spermatheca of the red-spotted newt

Several neurotransmitters and hormones with potential to trigger a simultaneous contraction of the oviducts and the spermathecal myoepithelium were examined. Saline (0.05 ml), or 0.05 ml saline plus acetylcholine (9 mg), norepinephrine (50 micrograms), arginine-vasotocin (25 units), prostaglandin F2 alpha (3 micrograms) were injected into the spermathecal region of female newts (n = 24 per group). The numbers of sperm present in the cloacae of prostaglandin-injected animals (107 +/- 30 SEM) were significantly greater than the numbers detected in saline (27 +/- 5 SEM) and in uninjected (14 +/- 3 SEM) controls. Smaller and less consistent increases in the numbers of sperm were detected in the vasotocin- and norepinephrine-injected groups. Study of sections from ovulating female newts failed to produce evidence that pressure from the passage of ova through the posterior portion of the oviduct forced sperm from the spermatheca. Observations indicate an active role for the spermathecal myoepithelium in the discharge of stored sperm and of a role for prostaglandin F2 alpha in triggering that discharge.     

Age distribution of circulating alpha-interferon

A sensitive radioimmunoassay showed that circulating alpha-interferon in the plasma of healthy individuals was low in children and reached the highest level in the young adult, then declined gradually with age. Circulating alpha-interferon was 0.201 +/- 0.059 ng/ml in males (n = 19) and 0.184 +/- 0.076 ng/ml in females (n = 14) at ages 30-39 years old. It was noted that circulating alpha-interferon was maintained up to a certain level even in elderly individuals.     

Effect of sex hormones on uric acid metabolism in rats.

The effects of sex hormones on purine metabolism were investigated in rats. No influence on purine synthesis was shown by the injection of estrogen and androgen. The plasma urate levels were significantly lowered from 2.43 +/- 1.04 mg/100 ml to 1.53 +/- 0.57 mg/100 ml by the injection of progesterone. Urinary excretion of uric acid plus allantoin was slightly reduced. These results suggested that progesterone may influence age and sex differences in human plasma urate levels.     

Human growth hormone in urine: development of an ultrasensitive radiometric assay

An immunoradiometric assay for human growth hormone (HGH) has been developed which has a detection limit of 1 ng/l and can measure HGH in unextracted urine from normal children and adults. The assay is based on a two-step procedure, using a solid-phase goat-anti-HGH immunosorbent for immunoextraction and [125I]-labeled monoclonal HGH-antibody for detection and quantification. The assay is not affected by urea, NaCl or changes of pH from 5-8. The mean urine HGH concentration in normal children is 6.78 +/- 7.6 (SD) pg/ml, in patients with HGH-deficiency 1.3 +/- 0.9 pg/ml which increases to 11.7 +/- 13.4 pg/ml on the day of growth hormone injection.     

High K+-induced release of somatostatin from the cortical preparation of rat brain.

Release of endogenous somatostatin (SRIF) from the rat cerebral cortical slices incubated in Krebs-bicarbonate buffer was increased from the basal rate of 3.4 +/- 0.6% of the total SRIF content in 15 min at [K+]o = 5.6 mM, to 13.1 +/- 1.6% upon raising the [K+]o to 56.6 mM. The high-K+ evoked SRIF release was absent when Ca++ in the medium was replaced by Mn++. The isolated synaptosomes from rat cerebral cortex contain 13.2 +/- 3.1 ng SRIF/mg protein compared to 0.33 +/- 0.01 ng/mg protein in the cortical tissue as a whole, suggesting that nerve terminals are the main source of the peptide released upon membrane depolarization.     

Effects of blood sampling, anesthesia and surgery on plasma vasopressin concentration in rats.

The influence of blood sampling, anesthesia and surgery on plasma vasopressin concentration was assessed in rats. Mean plasma concentration in conscious, chronically catheterized rats was 1.4 +/- 0.1 pg/ml (n = 6). This value remained constant over repeated plasma samplings in the same animals. On the other hand, decapitation increased the plasma vasopressin concentration to 6.0 +/- 2.4 (in pg/ml) (n = 6), inactin anesthesia to 2.9 +/- 0.6 (n = 6), anesthesia and femoral cannulation to 13.3 +/- 5.8 (n = 6) and surgery for renal micropuncture to 81.3 +/- 35.0 (n = 6). It is concluded that the level of circulating plasma vasopressin is highly dependent on the sampling technique and is closely related to the extent of surgery.     

Estimation of systemic catecholamine levels in the frog, using the technic of radio-enzymatic assay]

We have developed a radio-enzymatic assay for systemic catecholamines in the frog. Such are its specificity and sensibility that adrenaline and noradrenaline may be measured in 50 microliter of plasma samples, the withdrawal of which strongly influenced the results. The smaller values were obtained in plasma withdrawn from canulated animals. In this case, adrenaline was the major catecholamine in the plasma: 190 +/- 55 ng/100 ml versus 35 +/- 18 ng/100 ml for noradrenaline.     

Serum cholesterol levels in a Nigerian population sample

Serum cholesterol was determined in 104 healthy Nigerians (57 males and 47 females). The average cholesterol concentration was 187 +/- 72.8 mg/100 ml (mean +/- SD) with a range of 60-480 mg/100 ml. Cholesterol levels were higher in males than in females and increased with age. Distribution of cholesterol level was generally skew to the left.     

Alpha 1-adrenergic stimulation of ketogenesis and fatty acid oxidation is associated with inhibition of lipogenesis in rat hepatocytes

The effect of norepinephrine on fatty acid synthesis (3H2O incorporation into fatty acids), on fatty acid oxidation to CO2 and on ketogenesis was studied in isolated hepatocytes of fed rats. After incubation with norepinephrine (50 microM), lipogenesis was lower (5.7 +/- 1.1 nmoles 3H2O incorporated into fatty acids/mg dry weight/30 min) than in controls (7.5 +/- 1.7; n = 6, p less than 0.02). In contrast, (1-14C) palmitate conversion into total ketone bodies was increased to 10.9 +/- 1.8 nmoles/mg/30 min with norepinephrine, vs 8.5 +/- 1.6 in controls (p less than 0.05), and more (1-14C) palmitate was converted to 14CO2 with norepinephrine than in controls (1.48 +/- 0.10 nmoles/mg/30 min vs 1.06 +/- 0.11, p less than 0.05). The inhibitory effect of norepinephrine on lipogenesis was abolished by addition of the alpha 1-receptor blocker prazosin, but not by alpha 2 or beta-blockers. The results demonstrate that the ketogenic effect of norepinephrine is coupled with an inhibitory effect on lipogenesis which may be explained by diminished activity of acetyl-CoA carboxylase, diminished formation of malonyl-CoA and decreased activity of carnitine palmitoyl transferase I.     

Diploidy and triploidy in the hybrid minnow,Phoxinus eos x Phoxinus neogaeus (Pisces: Cyprinidae)

Summary Two presumptive hybrid populations are examined. Nebraskan hybrids, all having allozymic F1 electromorphs, exist as both diploid (2n=50) and triploid (3n=75) forms. This supports the hypothesis of parthenogenesis as the mode of hybrid reproduction. The maximum number of nucleoli per cell is suggested as an indicator of ploidy level. In contrast, electrophoretic analysis of a postulated Mendelian hybrid population in Quebec failed to detect any allozymic heterozygotes or recombinants. A previous conclusion of introgressive hybridization in this population is not supported.This research was supported by the Theodore Roosevelt Memorial Fund. We wish to thank Arthur Ostrowski for his generous assistance. Collection of the Quebec specimens was made possible through the kindness of Etienne Magnin. We acknowledge the Department of Biological Sciences, Wayne State University, for providing research facilities.     

Capillary blood flow in the testes and testosterone secretion in the starved rat

Summary The average capillary blood flow in the testes was found to be 181 l/min/g testis tissue (n=19) in rats starved for 5 days and 273 l/min/g (n=18, p<0.01) in the control group. Plasma testosterone was significantly decreased in the starved animals (1.00±0.06 ng/ml vs 5.43±0.63 ng/ml). When starved and control rats were stimulated with human chorion gonadotropin, testosterone values in plasma were greatly increased in both groups. The capillary blood flow was not altered. The data indicate that human chorion gonadotropin can stimulate testosterone production in the starved rat without influencing the reduced capillary blood flow.     

Modulation of carcinoembryonic antigen release by HT-29 colon carcinoma line in the presence of different agents

In this study we followed the effects of various differentiating agents on the expression of carcinoembryonic antigen (CEA) released into the medium by a colon carcinoma cell line HT-29. Butyric acid 1 mM markedly increased the level of CEA (12-fold in comparison to control levels). 12-O-tetradecanoyl-phorbol-13-acetate (TPA) 50 ng/ml and 5-azacytidine 4 x 10(-6) M increased the amount of CEA, 2- and 1.5-fold respectively. On the other hand retinoic acid 10(-5) M, N methyl-formamide 1% and N,N hexamethylene bisacetamide 2.5 mM decreased CEA 2-, 4- and 3-fold respectively. Our results emphasize that various differentiating agents affect CEA levels differently. Thus changes in CEA levels appear not to be reliable as a marker of a more differentiated phenotype.     

Insulin secretion and (pro)insulin biosynthesis of cultured mice islets after glibenclamide loading in vitro

Summary Isolated islets from C57B1/6J mice exposed to 10 mmoles/1 glucose supplemented with 5 g/ml glibenclamide for 48 h released significantly less insulin in the subsequent short-time incubation thanuntreated controls (without glibenclamide), whereas insulin biosynthesis was not suppressed by glibenclamide treatment.Investigations were carried out as a part of the ForschungsprojektDiabetes mellitus und Fettstoffwechselstörungen, supported by the Ministry of Health of the GDR.     

Substance P-induced fibrinolysis in the forearm of healthy humans

Physiological saline with or without substance P (50 ng/ml) was infused into the humeral artery in 6 healthy males. Indices of fibrinolytic activity (whole blood diluted lysis time, euglobulin lysis time, lysis areas in non-heated fibrin plates produced by plasma or euglobulin precipitate, plasminogen plasma levels, ₂-macroglobulin, Cl-inhibitor, and ₂-antiplasmin) were evaluated in the homolateral antecubital vein before and after 5 min of substance P or saline infusion. After substance P the fibrinolytic activity increased, as can be seen from the shortening of lysis times (p<0.01) and enlargement of the lysis areas (p<0.01). A reduction of plasminogen plasma levels (p<0.01), associated with a decrease in ₂-anitplasmin (p<0.01), was also found. Alpha₂-macroglobulin and Cl-inhibitor were instead unaltered by the peptide. The saline infusion, on the other hand, was unable to modify any of the examined indices. We concluded that exogenous substance P given intra-arterially increases fibrinolytic activity in locally-sampled venous blood through a mechanism which remains to be elucidated.     

Hormonal facilitation in the release of sperm from the spermatheca of the red-spotted newt

Summary Several neurotransmitters and hormones with potential to trigger a simultaneous contraction of the oviducts and the spermathecal myoepithelium were examined. Saline (0.05 ml), or 0.05 ml saline plus acetylcholine (9 mg), norepinephrine (50 g), arginine-vasotocin (25 units), prostaglandin F₂(3g) were injected into the spermathecal region of female newts (n=24 per group). The numbers of sperm present in the cloacae of prostaglandin-injected animals (107±30 SEM) were significantly greater than the numbers detected in saline (27±5 SEM) and in uninjected (14±3 SEM) controls. Smaller and less consistent increases in the numbers of sperm were detected in the vasotocin- and norepinephrine-injected groups. Study of sections from ovulating female newts failed to produce evidence that pressure from the passage of ova through the posterior portion of the oviduct forced sperm from the spermatheca. Observations indicate an active role for the spermathecal myoepithelium in the discharge of stored sperm and of a role for prostaglandin F₂ in triggering that discharge.     

循环雌二醇及代谢物与绝经后乳腺癌的相关性

目的探讨循环雌二醇（E2）、4-羟雌二醇（4-OHE2）、2-甲氧雌二醇（2-MOE2）水平及4-羟雌二醇：2-甲氧雌二醇（4-OHE2：2-MOE2）比值与绝经后乳腺癌危险性的相关性。方法采用ELISA法检测绝经后34例乳腺癌、40例乳腺良性（乳腺纤维腺瘤与乳腺囊性增生病）疾病患者和20例正常对照循环雌二醇、4-羟雌二醇、2-甲氧雌二醇水平并计算4-羟雌二醇：2-甲氧雌二醇比值。结果乳腺癌组及乳腺良性疾病组循环2-甲氧雌二醇水平差异无统计学意义（P〉0．05）,但均较正常对照组低（P〈0．05）;乳腺癌组及乳腺良性疾病组4-羟雌二醇：2、甲氧雌二醇比值差异无统计学意义（P〉0．05）,但均较正常对照组升高（P〈0．05）。乳腺癌Ⅰ期～Ⅲ期各期循环雌二醇、4．羟雌二醇、2-甲氧雌二醇、4-羟雌二醇：2-甲氧雌二醇比值差异无统计学意义（P〉0．05）。4-羟雌二醇、2．甲氧雌二醇、4．羟雌二醇：2-甲氧雌二醇比值在乳腺癌ER（-）组与ER（＋）组间差异无统计学意义（P〉005）,但ER（＋）组雌二醇水平较ER（-）组明显升高（P〈0．05）。结论2．甲氧雌二醇与绝经后乳腺疾病负相关;4-羟雌二醇：2-甲氧雌二醇比值可能预示绝经后乳腺疾病危险。     

Cutaneous respiration in a Selachian (Scyliorhinus caniculus L.)]

Cutaneous oxygen consumption (Mo2) and cutaneous oxygen uptake from the external medium were investigated in an elasmobranch Scyliorhinus caniculus L. In spite of an important Mo2 (2.75 +/- 0.28 nmol.mn-1 cm-2 ; n=6) a positive net flux of oxygen through the skin takes place (2.98 +/- 0.33 nmol. mn-1 .cm-2). The skin of the dogfish in an exchanger for oxygen supplying 10% of oxygen requirements of other organs of the body in these experimental conditions (t = 13 degrees C).     

Frequency of locus E1 variants of plasma butyrylcholinesterase in a French population]

Human plasma cholinesterase (E.C.3.1.1.8) from 1,594 blood donors was phenotyped on the basis of dibuca?ne, fluoride, chloride and succinylcholine differential inhibitions according to the criteria of Brown et coll. The observed gene frequencies are: E1u = 0.970,8, E1a = 0.188,0, E1f = 0.103,0.     

La formule chromosomiale de la race bisexuée dePycnoscelus surinamensis L., comparée à celle de la race parthénogénétique

Summary The author has shown in 1945 that the thelytokous strain ofPycnoscelus surinamensis L. could not be a triploid one. This assumption is fully proved by the examination of the bisexual strain of which some individuals were obtained from Malaya. Both strains have the same chromosomic complement: 2N=37; 2N=38. In the male of the bisexual stock one may observe a lagging of a chromosome in the spermatogonial mitosis as well as in the second maturation divisions. We have here to do with a case of geographical parthenogenesis without polyploidy.