Immunoreactive erythropoietin concentration and haemoglobin type in the perinatal period in sheep of various haemoglobin genotypes

This study examines the hypotheses that (i) erythropoietin (the hormone responsible for red blood cell production) is higher in the fetus (at low PO2) than in the neonate (at high PO2); and (ii) that the level of erythropoietin in the neonate is influenced by the presence of high oxygen affinity haemoglobin. Haematocrit (PCV), PO2 and plasma immunoreactive erythropoietin were measured in 4 chronically cannulated fetal sheep (120 days to birth, n = 22) and in 7 neonatal lambs until 233 days post-conception (75-85 days after birth, n = 83). The percentage of globin chains (alpha, gamma, beta A, beta B, beta C) was quantitated by gel electrophoresis. Plasma erythropoietin values, in 4 fetuses were 9.8 +/- 1.3 mU/ml at 120-132 days of gestation, declined significantly (P less than 0.01) to 5.2 +/- 0.4 at 133 days until birth, then increased significantly (P less than 0.001) to 24.2 +/- 5.5(5), 26.3 +/- 7.3 (6), and 24.8 +/- 8.5 (6), respectively in weeks 1, 2 and 3 of postnatal life. By weeks 5-8 the erythropoietin was 13 +/- 0.6 (4) mU/ml. PO2 was 17.4 +/- 0.9 mmHg before birth and 88.0 +/- 10.7 in the first week after birth. PCV was constant until three weeks after birth and then declined. Fetal haemoglobin had virtually disappeared from the circulation by 166 days (3 weeks after birth); in the 4 heterozygotes (beta A beta B) beta C was expressed transiently, with a maximum value of 4%, whilst in the homozygote lamb (beta A beta A) the maximum beta C was 12%.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of haemorrhage on erythropoietin concentration in the mature ovine fetus.

This study examines the response in plasma erythropoietin values to haemorrhage of 20% of the estimated blood volume in chronically cannulated ovine fetuses, of gestational ages 128-144 days. Blood samples were collected at 0, 2, 4, 6 and 24h with respect to the haemorrhage. In 5 control experiments there was no significant change in plasma erythropoietin concentration, across this time period, values being 6.1 +/- 2.3 and 6.4 +/- 2.4 mU/ml at 0 and 24h respectively. Values are mean +/- SEM. Haemorrhage reduced the haematocrit and haemoglobin values, significantly, to 83 +/- 6% and 85 +/- 4% (n = 5) of the initial value, respectively, but did not cause a statistically significant increase in plasma erythropoietin concentrations (7.2 +/- 2.4 and 20.7 +/- 8.2 mU/ml; P = 0.131). A larger degree of haemorrhage, in four fetuses reduced the haematocrit to 64 +/- 2.8% of initial, over 24-54h and increased erythropoietin values very significantly (from 11.9 +/- 3.6 to 91 +/- 8.3 mU/ml; P = 0.001).     

Pituitary response to GnRH and ovariectomy in Booroola-Awassi and Awassi ewe lambs

Booroola-Awassi ewe lambs were heterozygous (F+) for a major gene F, influencing their ovulation rate, while Awassi lambs were non-carriers (++). Basal plasma FSH concentration (mean +/- s.e.m.) in Booroola-Awassi ewe lambs at 4 weeks of age was significantly higher than in Awassi lambs of the same age (5.06 +/- 0.60 and 2.04 +/- 0.32 ng/ml respectively; P less than 0.001). After GnRH administration, FSH increased from 3.89 +/- 1.10 to 10.58 +/- 1.30 ng/ml in Booroola-Awassi (N = 6) and from 1.87 +/- 0.29 to 4.64 +/- 0.33 ng/ml in Awassi (N = 6) ewe lambs (P less than 0.05). Ovariectomy caused an increase in plasma FSH in Booroola-Awassi (N = 4) and Awassi (N = 4) ewe lambs. At 1 week after ovariectomy plasma FSH increased from 5.96 +/- 1.02 to 7.06 +/- 1.05 ng/ml in F+ and from 1.67 +/- 1.06 to 5.21 +/- 0.66 ng/ml in ++ ewe lambs, suggesting a stronger negative feed-back effect exerted by the ovaries of Awassi lambs. At 15 weeks after ovariectomy FSH values were similar in Booroola-Awassi (18.28 +/- 1.96 ng/ml) and Awassi (16.07 +/- 0.70 ng/ml) lambs. Although the overall pattern of pituitary response to ovariectomy was similar in the F+ and ++ ewe lambs, Booroola-Awassi lambs had small ovaries (132.5 +/- 24.9 mg) and follicular development did not proceed beyond the preantral stage in 3/4 animals, and Awassi lambs had large ovaries (600.0 +/- 233.9 mg) (P less than 0.05) with many preantral and antral follicles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Decrease of erythropoietin level by human recombinant tumour necrosis factor alpha (hrec TNFalpha) in patients with advanced cancer

Anaemia is a frequent complication of chronic inflammation, infectious diseases and cancer. Inappropriate erythropoietin production is regarded as one of the main causative factors responsible for the occurrence of anaemia. The pathogenesis of TNFalpha induced-anaemia has not been fully clarified yet and its influence on hematopoiesis has been suggested. We performed a clinical study to access the influence of hrec TNFalpha administration on plasma EPO concentration and the degree of anaemia in patients with advanced solid tumours for whom no other kind of therapy but palliative treatment was available. All these patients exposed mild anaemia (HT 36.1 +/- 1.0%). Plasma EPO was estimated at 8 a.m. before and after 5 days of TNFalpha therapy with a dose of 75 pg/day iv (cycle I). Two weeks later plasma EPO was estimated again before and after 5 days of TNFalpha administration of a double dose (150 microg/day) (cycle II). The control group comprised 8 non-cancer patients (5M/3F, age 48.5 +/- 6yr) with the same degree of anaemia (HT 36 +/- 1.1%) due to haemorrhage. In the control group the plasma EPO level was significantly higher (54.2 +/- 8 mU/ml) than in cancer patients before cycle I (17.1 +/- 2.5 mU/ml) and II (14.6 +/- 3.8 mU/ml) respectively.TNF administration was followed by a significant decline of plasma EPO both after the first (17.1 +/- 2.5 vs 9.0 +/- 1.5 mU/ml) and second cycle (14.6 +/- 3.8 vs 8.4 +/- 2.0 mU/ml) of TNF treatment. CONCLUSIONS: Patients with solid cancer and mild anaemia are characterised by inappropriate low plasma EPO concentration. Therapy with TNFalpha exerts a suppressive effect on EPO secretion in these patients.     

Plasma LH,FSH, testosterone,and age at puberty in ram lambs actively immunized against an inhibin alpha-subunit peptide

Active immunization against inhibin has been shown to advance puberty and increase ovulation rate in ewe lambs; but in ram lambs, effects on puberty and sperm production are equivocal. The objective of the present study was to determine whether active immunization against an inhibin alpha-subunit peptide advances the onset of puberty in ram lambs. St. Croix hair sheep ram lambs were assigned to inhibin-immunized (n = 7) and control (n = 8) treatment groups. Lambs in the inhibin-immunized group were immunized against a synthetic peptide-carrier protein conjugate, alpha-(1-25)-human alpha-globulin (halpha-G), and control lambs were immunized against halpha-G. Lambs were immunized at 3, 7, 13, 19, 25, 31, and 37 weeks of age. On the day of immunization a blood sample was collected and lambs were weighed. Another blood sample was collected 1 week following each immunization. At 20 weeks of age additional blood samples were collected at 20 min intervals for 8h. Beginning at 20 weeks of age and at weekly intervals thereafter, scrotal circumference (SC) was measured and semen was collected using electroejaculation. A subsequent ejaculate was collected 1 week following onset of puberty, which was defined as the week of age when an ejaculate first contained > or =50 x 10(6) sperm cells. In control lambs, plasma alpha-(1-25)-antibody (Ab) was nondetectable. In inhibin-immunized lambs, alpha-(1-25)-Ab titer increased from 7 to 25 weeks of age and then plateaued at a level that varied (P<0.001) among animals. Body weight and SC of control and inhibin-immunized lambs were similar at the onset of puberty. At pubertal onset inhibin-immunized lambs were older than control lambs (31.9+/-0.5 vs. 29.5+/-0.7 weeks of age, P<0.05). Plasma FSH concentrations were similar in control and inhibin-immunized lambs from 3 to 38 weeks of age. Plasma LH levels were lower (P<0.01) in inhibin-immunized than control lambs. During the 8-h blood sampling period at 20 weeks of age, LH and testosterone concentrations were lower (P<0.05) in inhibin-immunized than control ram lambs, and the LH pulse frequency was similar in the two groups of animals. The decreased LH secretion is consistent with the immunoneutralization of a putative inhibin alpha-subunit-related peptide that stimulates LH secretion in ram lambs. Present findings show that active immunization against an inhibin alpha-peptide delays rather than advances puberty in ram lambs.     

Circulating vasoactive substances and hemodynamic adjustments at birth in lambs

Circulating vasoactive substances and hemodynamics were examined in chronically instrumented unanesthetized lambs before, during, and after cesarean section (spontaneous respiration). One of three infusions were started 20 min before birth: saline control (n = 10), saralasin (n = 5), or captopril (n = 6). Control lambs exhibited peak (means +/- SE) increases above fetal base line at 5 min after birth in plasma renin activity (5.0 +/- 1.1 to 11.0 +/- 3.4 ng.ml-1.h-1), angiotensin II (ANG II, 37 +/- 6 to 141 +/- 45 pg/ml) and total catecholamines (318 +/- 35 to 3,821 +/- 580 pg/ml). Mean systemic arterial pressure (Psa) and arterial O2 partial pressure (PaO2) increased more rapidly and to a greater extent by 1 h after birth in control lambs (Psa, 65 +/- 1 Torr; PaO2, 45 +/- 3 Torr) compared with the captopril group (Psa, 53 +/- 2 Torr; PaO2, 31 +/- 4 Torr) and the saralasin group (Psa, 56 +/- 2 Torr; PaO2, 27 +/- 3 Torr). Intravenous infusions of ANG II in control lambs, 2 h after birth resulted in a preferential systemic vs. pulmonary pressor response. The results demonstrate that at birth ANG II formation fosters the postnatal rise in Psa and PaO2, and high levels of circulating catecholamines may support postnatal cardiac output and Psa.     

Effect of melatonin on pulsatile release of luteinizing hormone in female lambs.

This study investigated the effect of melatonin treatment of ewe lambs on LH pulsatility in an attempt to examine the mechanism whereby melatonin advances the onset of puberty. Six ewe lambs were given intravaginal melatonin implants at 12.8 weeks of age. Another six lambs received empty implants. All lambs were serially blood sampled every 15 minutes for six hours on several occasions prior to the onset of puberty. One week after implantation LH pulse frequency and mean LH levels were higher in treated lambs than the control lambs (pulse frequency 0.13/h vs 0.03/h; mean LH levels 2.0 +/- 0.2 ng/ml vs 1.3 +/- 0.1 ng/ml; p less than 0.05). Melatonin treatment failed to alter pulse frequency after the initial increase. Puberty was advanced by 3 weeks in the treated group. In the second experiment six lambs received melatonin implants at 13 weeks of age and another six lambs served as control. In this experiment blood samples were taken intensively during the first few weeks after treatment. Results of this study show that mean plasma LH levels and LH pulse frequency were again higher during the first week after implantation. This transient increase in LH release may be part of the mechanism initiating the eventual advancement of puberty although the significance of this increase is questionable. In both experiments the LH response to estradiol injection was monitored at various times after treatment, but no effects of melatonin were found, although the magnitude of the response increased with age.     

Effect of naloxone on gonadotrophin secretion at various stages of development in the ewe lamb

Spring-born crossbred ewe lambs were raised in a natural photoperiod and saline (N = 6) or naloxone (1 mg/kg) in saline (N = 6) was injected (i.m.) every 2 h for 6 h at 5, 10 and 15 weeks of age and for 8 h at 20, 25 and 30 weeks of age. Blood samples were taken every 12 min during treatment periods. Naloxone had no effect on time to first oestrus (controls 235 +/- 6 days, naloxone 242 +/- 7 days). Mean serum LH concentrations and LH pulse frequency were elevated by naloxone in ewe lambs at 20, 25, and 30 weeks of age (P less than 0.05). The only FSH response to naloxone was a depression of mean serum concentrations at 30 weeks of age (P less than 0.05). LH pulse amplitude was elevated at 5 weeks of age in all ewe lambs and declined thereafter to a nadir at 30 weeks of age in control, but not in naloxone-treated animals (P less than 0.05). LH pulse frequency was elevated at 10 weeks of age in control ewe lambs and in all animals at 30 weeks of age (P less than 0.05). FSH pulse frequency declined from 5 weeks of age in control ewe lambs (P less than 0.05), with very few pulses noted in 25- and 30-week-old animals. We conclude that (1) opioidergic suppression of LH, but not FSH, secretion developed at 20 weeks of age in the growing ewe lambs used in the present study, with no obvious change in suppression before the onset of first oestrus: (2) pulsatile FSH secretion occurred in the young ewe lamb but was lost as the lamb matured: (3) attainment of sexual maturity was preceded by an elevation in LH pulse frequency.     

Reproductive characteristics of lambs actively immunized early in life with inhibin-enriched preparations from follicular fluid of cows

Active immunization of Merino and crossbred ewe lambs early in life with a partly purified inhibin derived from bovine follicular fluid (bFF) advanced their puberty. This occurred whether the lambs were immunized from 3 weeks of age or from 9 weeks of age or just 3 times between 3 and 9 weeks. However, the effect was more obvious with multiple injections starting at 3 weeks of age. The ovulation rate of the immunized lambs was significantly higher than that of the control ewes. When lambs were subjected to multiple immunizations the increased ovulation rate persisted in Merinos for at least 1 year after immunization ceased. The lambs injected 3 times only (at 3, 6 and 9 weeks of age) did not show any increase in ovulation rate. Plasma concentrations of FSH and LH measured in blood samples taken 1 week after immunization were not significantly different between the treatment groups. Daily sperm output in the urine and testis diameter were measured in ram lambs from the same breeds and flocks as the ewe lambs. Immunization with the inhibin preparation from 3 weeks of age resulted in a significant increase in daily sperm output (4255 +/- 701 vs 2344 +/- 344 x 10(6), P less than 0.01) and testis diameter (5.21 +/- 0.3 vs 4.33 +/- 0.2 cm, P less than 0.05) in Merino rams examined in the non-breeding season when the rams were aged 23 months. Although the same trend was seen in the following year the differences were not significant. Immunization from 9 weeks of age had no effect. A similar increase in daily sperm output was seen (at 20 and 25 months of age) in crossbred rams immunized from 3 weeks of age but the difference was not significant. Plasma concentrations of FSH (but not LH) in samples from rams immunized from 3 weeks of age were significantly higher than those of control rams at 7 and 60 weeks of age in Merino rams and at 23 and 31 weeks of age in crossbred rams. Plasma FSH concentrations at 21 and 26 weeks of age in the Merino rams immunized from 3 weeks of age were higher than those of control lambs, and these increases preceded a significant (P less than 0.05) increase in testicular diameter at 30 weeks of age (4.99 +/- 0.2 vs 4.37 +/- 0.2 cm). These results suggest that active immunization early in life with an inhibin-enriched fraction from bFF advances puberty in ewe lambs.(ABSTRACT TRUNCATED AT 400 WORDS)     

Serum concentrations of oestradiol and progesterone, and sexual behaviour during the normal oestrous cycle in the leopard (Panthera pardus)

Three mature nulliparous female leopards were studied for 5 years. During three separate 6-month periods serum oestradiol and progesterone concentrations were measured at weekly intervals. Oestradiol was elevated over 21 pg/ml for 54 weeks during these 3 periods, and 36 oestradiol peaks (65.8 +/- 6.3 pg/ml (mean +/- s.e.m.), range 21-172 pg/ml) were identified. Daily frequency of feline reproductive behaviours averaged over each week increased from 1.9 +/- 0.2 (n = 93) during weeks with low serum oestradiol concentrations (less than 21 pg/ml) to 5.3 +/- 0.6 (n = 54) during weeks when serum oestradiol concentrations (greater than 21 pg/ml) were high. Increased serum progesterone concentrations (13-98 n/gml) were observed on 5 occasions in 2 leopards housed together. These presumptive luteal phases lasted from 1 to 5 weeks. Baseline progesterone values were 1.6 +/- 0.4 ng/ml (n = 131). No progesterone increments were observed in isolated animals, and serum concentrations remained at baseline levels. These limited observations suggest that female leopards do not require intromission to induce ovulation and luteal function. The average interval between oestradiol peaks for cycles with no progesterone increment was 3.4 weeks (range 1-6 weeks). The interval for the 3 complete cycles associated with elevated progesterone concentrations was 7.3 weeks. Analysis of sexual behaviours over the 5-year study period revealed no evidence of seasonality in these captive leopards.     

Development of pulmonary intravascular macrophage function in newborn lambs.

We sought to determine whether pulmonary intravascular macrophages are involved in pulmonary vascular sensitivity to intravenously injected particles in sheep. We estimated that newborn lambs have few of these macrophages at birth but develop a 10-fold greater density within 2 wk. Awake, chronically instrumented newborn lambs showed no change in pulmonary vascular driving pressure (pulmonary arterial minus left atrial pressure) after injection of either liposomes [2 +/- 3 (SD) cmH2O; n = 5] or Monastral blue particles (3 +/- 2 cmH2O; n = 6) and showed no net pulmonary production of thromboxane B2, the stable metabolite of the vasoconstrictor thromboxane A2. In contrast, five of those lambs 2 wk later showed both an increase in pulmonary vascular driving pressure after injection of liposomes and Monastral blue (20 +/- 16 and 25 +/- 15 cmH2O, respectively; P < 0.05) and net pulmonary production of thromboxane B2 (171 +/- 103 and 429 +/- 419 pg/ml plasma, respectively; P < 0.05). Older lambs (n = 5) had higher pulmonary uptakes than newborn lambs (n = 6) of radioactive liposomes (47 +/- 13 vs. 12 +/- 10%; P < 0.01) and Monastral blue (53 +/- 6 vs. 21 +/- 10%; P < 0.05). We conclude that pulmonary intravascular macrophages are responsible for the sensitivity of sheep to intravenous foreign particles and are essential for a cascade of processes leading to microvascular injury.     

3T3-L1脂肪细胞对MIN6胰岛素细胞中Kir6.2表达的抑制作用

为明确脂肪细胞对胰岛素细胞中KATP通道表达的直接影响,MIN6胰岛素细胞被分为两组：一组为对照组,一组与分化的3T3-L1脂肪细胞共培养1周。运用半定量RT-PCR方法测定MIN6细胞中KATP通道蛋白Kir6．2的表达变化,Fura-2荧光方法测定MIN6细胞内钙浓度的变化,放射免疫测定方法明确MIN6细胞的胰岛素分泌功能。结果显示,与3T3-L1脂肪细胞共培养1周后,MIN6细胞中Kir6．2的表达明显减少,其表达水平降低为对照组的65．3％。对照组MIN6细胞在0．1mmoi／L甲苯磺丁脲(KATP通道关闭剂)的刺激下,表现为细胞内钙水平显著性升高和胰岛素分泌显著性增加,而共培养组MIN6细胞则失去了甲苯磺丁脲刺激所引起的细胞内钙升高及胰岛素分泌反应。以上实验结果表明,3T3-L1脂肪细胞可以通过分泌一些活性因子直接降低MIN6细胞中KATP通道蛋白的表达和合成,损害MIN6细胞的胰岛素分泌功能。实验结果提示脂肪细胞直接参与2型糖尿病中胰岛β细胞功能障碍的发生。     

Pulmonary hemodynamics at birth: effect of acute cyclooxygenase inhibition in lambs

The effect of acute cyclooxygenase (CYO) inhibition on the cardiopulmonary adjustments at birth was examined in chronically instrumented, unanesthetized, term lambs before, during, and after cesarean section (spontaneous respiration). One of three infusions was started 20 min before birth: saline control (C, n = 6), indomethacin (I, n = 6), or meclofenamate (M, n = 3). The stable metabolite of prostacyclin, plasma 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha, aorta), was measured by radioimmunoassay as an index of CYO activity. Indomethacin blocked the rise of 6-keto-PGF1 alpha observed in control lambs after birth and indomethacin-treated lambs exhibited an attenuation of the postnatal decrease in mean pulmonary arterial pressure. Pulmonary arterial pressure (Ppa) was 53 +/- 2 and 47 +/- 2 Torr (mean +/- SE) at 15 min and 40 +/- 3 and 34 +/- 2 Torr at 120 min in I and C groups, respectively. There were no serial or group differences in cardiac output and cardiac right to left shunt (indicator dilution) from 15 to 120 min after birth. Arterial PO2 (PaO2) was not different between groups: 37 +/- 4 Torr at 15 min and 47 +/- 5 min at 120 min after birth (control lambs). The results for I and M were similar for all measurements.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simulated first-phase insulin release using Humulin or insulin analog HIM2 is associated with prolonged improvement in postprandial glycemia

We examined the extent to which priming the liver with a pulse of Humulin or the insulin analog hexyl-insulin monoconjugate 2 (HIM2) reduces postprandial hyperglycemia. Somatostatin (0.5 microg.kg(-1).min(-1)) was given with basal intraportal insulin and glucagon for 4.5 h into three groups of 42-h-fasted conscious dogs. From 0-5 min, group 1 (BI, n = 6) received saline, group 2 (HI, n = 6) received a Humulin pulse (10 mU.kg(-1).min(-1)), and group 3 (HIM2, n = 6) received a HIM2 pulse (10 mU.kg(-1).min(-1)). Duodenal glucose was infused (5.0 mg.kg(-1).min(-1)) from 15 to 270 min. Arterial insulin in BI remained basal (6 +/- 1 microU/ml) and peaked at 52 +/- 15 (HI) and 164 +/- 44 microU/ml (HIM2) and returned to baseline by 30 and 60 min, respectively. Arterial plasma glucose plateaued at 265 +/- 20, 214 +/- 15, and 193 +/- 14 mg/dl in BI, HI, and HIM2. Glucose absorption was similar in all groups. Significant net hepatic glucose uptake occurred at 85, 55, and 25 min in BI, HI, and HIM2, respectively. Nonhepatic glucose clearance at 270 min differed among groups (BI, HI, HIM2): 0.62 +/- 0.11, 0.76 +/- 0.26, and 1.61 +/- 0.29 ml.kg(-1).min(-1) (P < 0.05). A brief (5-min) insulin pulse improved postprandial glycemia, stimulating hepatic glucose uptake and prolonging enhancement of nonhepatic glucose clearance. HIM2 was more effective than Humulin, perhaps because its lowered clearance caused higher levels at the liver and periphery and its biological activity was not reduced proportionally to its decreased clearance.     

Effects of treatment with LH or FSH from 4 to 8 weeks of age on the attainment of puberty in bull calves

A transient increase in gonadotropin secretion between 6 and 20 weeks of age is critical for the onset of puberty in bull calves. To try and hasten the onset of puberty, bull calves were treated (s.c.) with 3 mg of bLH (n = 6) or 4 mg of bFSH (n = 6) once every 2 days, from 4 to 8 weeks after birth; control calves received saline (n = 6). At 4 and 8 weeks of age, mean LH concentrations were higher (P < 0.05) in bLH-treated (2.3 +/- 0.04 ng/ml and 1.20 +/- 0.04 ng/ml) as compared to control calves (0.50 +/- 0.1 ng/ml and 0.70 +/- 0.10 ng/ml). Mean serum FSH concentrations at 4 and 8 weeks of age, were higher (P < 0.05) in bFSH-treated (1.60 +/- 0.20 ng/ml and 1.10 +/- 0.2 ng/ml) as compared to control calves (0.38 +/- 0.07 ng/ml and 0.35 +/- 0.07 ng/ml). The age at which scrotal circumference (SC) first reached > or = 28 cm, occurred earlier (P < 0.05) in bFSH-treated calves as compared to saline-treated calves (39.3 +/- 1.3 and 44.8 +/- 1.3 weeks of age, respectively). Based on testicular histology at 56 weeks of age, treatment with bFSH resulted in greater (P < 0.05) numbers of Sertoli cells (5 +/- 0.2, 6 +/- 0.3 and 5 +/- 0.3 in bLH-, bFSH- and saline-treated calves, respectively); elongated spermatids (42 +/- 2, 57 +/- 8 and 38 +/- 5 in bLH-, bFSH- and saline-treated calves, respectively) and spermatocytes (31 +/- 3, 38 +/- 3 and 29 +/- 2 in bLH-, bFSH- and saline-treated calves, respectively) per seminiferous tubule. We concluded that treatment of bull calves with bFSH from 4 to 8 weeks of age increased testicular growth (SC); hastened onset of puberty (SC > or = 28 cm); and enhanced spermatogenesis.     

Ciprofloxacin concentrations in serum, bone and bone marrow of rabbits

Ciprofloxacin concentrations were determined in serum, bone and bone marrow of rabbits. Four experimental groups of animals were examined: group A (n = 6) received a dosage of 60 mg/kg/day intramuscularly for 4 weeks, groups B (n = 6), C (n = 15) and D (n = 15) received dosages of 120 mg/kg/day subcutaneously for 2 days, 2 weeks, and 4 weeks, respectively. In the kinetic portion of the study, peak serum concentrations of ciprofloxacin measured at the 15 min sampling time were: 2.61 +/- 0.27 micrograms/ml in the 60 mg/kg/day group (group A) and 3.24 +/- 0.78 micrograms/ml in the 120 mg/kg/day group (group B). At necropsy, rabbits in group A had mean ciprofloxacin concentrations of 3.60 +/- 2.27 micrograms/ml in serum, 2.24 +/- 1.19 micrograms/g in marrow and 1.19 +/- 0.44 micrograms/g in bone. Rabbits in group B achieved mean levels of 4.02 +/- 1.23 micrograms/ml in serum, 2.48 +/- 0.79 micrograms/g in marrow, and 1.35 +/- 0.40 micrograms/g in bone. Rabbits in group C achieved mean levels of 5.65 +/- 2.16 micrograms/ml in serum, 3.74 +/- 1.33 micrograms/g in marrow and 1.92 +/- 0.94 micrograms/g in bone. Rabbits in group D achieved mean levels of 7.24 +/- 2.50 micrograms/ml in serum, 4.48 +/- 1.68 micrograms/g in marrow, and 1.93 +/- 0.54 micrograms/g in bone. Differences between mean values for the four experimental groups were not statistically significant.     

Clinical study on early changes in thyroid function of hyperthyroidism treated with propylthiouracil and a relatively small dose of iodide.

In order to compare the acute effects of three kinds of antithyroid agents of iodide (I-), propylthiouracil (PTU) and PTU combined with iodide (PTU+I-) on thyroid function in hyperthyroid patients with diffuse goiter, serum concentrations of thyroxine (T4), triiodothyronine (T3), T3-resin sponge uptake (T3-RU) and free thyroxine index (FT4I) were employed as thyroid function parameters. In the group given iodine (1 mg/day) as iodinated-lecithine, the initial values of T4, T3, T3-RU and FT4I were 20.9 +/- 1.6 microng/100 ml (T4), greater than 740 ng/100 ml (T3), 49.5 +/- 2.3% (T3-RU) and 14.7 +/- 1.8 (FT4I). At the end of one week of therapy, they decreased clearly to 15.6 +/- 2.2 microng/100 ml, 457 +/- 87 ng/100 ml, 42.2 +/- 4.0% and 9.7 +/- 2.4. The so-called "escape phenomenon" from iodide inhibition was observed in serum T4, T3-RU and FT4I values at the end of two weeks of iodide therapy, while serum T3 continued to decrease but the value of T3 was far outside of the normal range. In the PTU group (300 mg/day), thyroid function parameters were 22.5 +/- 0.8 microng/100 ml (T4), greater than 592 ng/100 ml (T3), 54.9 +/- 1.0% (T3-RU) and 18.7 +/- 1.0 (FT4I) before treatment. They decreased continually week by week. At the end of four-week treatment with PTU, the value of each thyroid function parameter was 11.1 +/- 1.9 microng/100 ml, 229 +/- 56 ng/100 ml, 36.6 +/- 4.4% and 5.7 +/- 1.7. In the group of hyperthyroidism simultaneously given both PTU and iodide (300 mg/PTU and 1 mg/iodine), these thyroid function parameters decreased as well as in the group treated with PTU alone for more than two weeks. More rapid or significant decrease of T4, T3, T3-RU and ft4i in PTU+I- group than in PTU group was observed in the present study. These results suggested strongly that iodide alone was not an adequate therapy for hyperthyroidism as well known and they were also compatible with the idea that the concomitant administration of PTU and iodide was more effective in the early phase of therapy of hyperthyroidism than PTU alone.     

hCG treatment on day of mating improves embryo viability and fertility in ewe lambs

An investigation was conducted to determine the effects of supplementing hCG at mating time on luteal function, conceptus growth, placentation and reproductive performance in TexelxClun Forest ewe lambs. After oestrus synchronisation with progestagen sponges and PMSG ewe lambs were treated either with normal saline (n=102) or 150 IU of hCG (n=105) at mating time. At 25 days after mating 24 animals were slaughtered from each group to determine embryo viability and placental development. hCG significantly (P<0.05) increased crown-rump length (saline: 11.9+/-0.2 mm; hCG: 12.7+/-0.2 mm), amniotic sac width (saline: 11.4+/-0.4 mm; hCG: 12.0+/-0.3 mm) and the number of placentomes (saline: 90.8+/-7.3; hCG=122.4+/-6.3). Among the pregnant animals that were slaughtered on 25 days post-mating, ovulation rate tended to be higher in the hCG group compared to controls (saline: 1.16; hCG: 1.54). However, no difference was observed either in mean plasma progesterone concentrations (saline: 4.6 ng/ml; hCG: 4.9 ng/ml; sed 0.56) or in progesterone production from luteal slices when cultured in vitro (saline: 239.6+/-11.8 ng/mg; hCG: 263.2+/-13.6 ng/mg) between controls and hCG treated animals. Reproductive performance was also recorded in ewe lambs that were either treated with saline (n=78) or hCG (n=81). The total number of lambs born (saline: 38; hCG: 58) was significantly (P<0.05) greater in hCG group compared to saline-treated controls. Both lambing percentage (saline: 36%; hCG: 48%) and litter size (saline: 1.35; hCG: 1.48) tended to be greater (P<0.10) in hCG-treated animals compared to the controls. In conclusion, these data suggest that treatment of ewe lambs with hCG at the time of mating improves conceptus growth, placentation and number of lambs born.     

Incorporation of [3H]thymidine by isolated fetal myoblasts and fibroblasts in response to human placental lactogen (HPL): possible mediation of HPL action by release of immunoreactive SM-C

We investigated the actions of human placental lactogen (HPL) and human growth hormone (HGH) on [3H]thymidine incorporation and the release of immunoassayable somatomedin-C (SM-C) by isolated myoblasts, dermal fibroblasts, and costal cartilage explants taken from human fetuses at 11-21 weeks of gestation. The incorporation of [3H]thymidine by myoblasts and fibroblasts was significantly increased after incubation for 20 hr or 44 hr, and cell number after incubation for 7 days, in the presence of 50-250 ng/ml HPL. Incubation with HPL did not increase [3H]thymidine incorporation into cartilage explants, whereas incubation with HGH failed to enhance the uptake of this isotope by any of the tissues. Following extraction with acid-ethanol, culture medium conditioned by exposure to myoblasts or fibroblasts for 44 hr, and to cartilage explants for 7 days, contained radioimmunoassayable SM-C. Myoblast-conditioned medium contained significantly more SM-C [1,609 +/- 953 mU/mg cell protein (mean +/- SD); n = 10] than did that conditioned by fibroblasts (637 +/- 323; n = 5; P less than 0.02). In 1 week of culture, cartilage explants released 4.1 +/- 1.1 mU/mg wet weight (n = 7). The release of immunoassayable SM-C from cultured cells was significantly increased in the presence of 250 ng/ml HPL in five of eight experiments with myoblasts and two of four experiments with fibroblasts. Neither fibroblasts or myoblasts showed increased SM-C release following exposure to HGH. The results suggest that HPL, but not HGH, is growth-promoting for some human fetal tissues in vitro and that this action is mediated, at least in part, by an increased release of somatomedins.     

Action of aldosterone on citrate synthase in cultured renal collecting duct cells

Cultured renal collecting duct cells from neonatal rabbit kidney were used to examine the influence of aldosterone on enzymatic activity of citrate synthase during increase in Na+ transport. Control epithelia showed citrate synthase activity of 71 +/- 3 mU/mg protein (n = 28), while after aldosterone treatment citrate synthase activity was significantly increased to 79 +/- 6 mU/mg at 1 h (n = 5), to 88 +/- 6 mU/mg at 2 h (n = 6) and to 93 +/- 8 mU/mg protein at 3 h (n = 5). Citrate synthase activity subsequently decreased to basal values. Spironolactone fully blocked the aldosterone-induced increase in citrate synthase activity. The time course of enzyme stimulation after aldosterone administration indicates that the hormone activates citrate synthase during the physiological early response phase.