Intratesticular Testosterone Concentration in Patients with Disturbed Fertility

45 patients with azoospermia or severe oligozoospermia were studied. Testosterone and luteinizing hormone in plasma were in the normal range. Intratesticular testosterone values were higher the greater the degree of tubular atrophy was. Patients with testes of subnormal size (less than 12 ml) had significantly higher values than those with normal sized gonads. 31 out of 37 testes obtained by castration of patients with carcinoma of the prostate showed slight to severe disturbance of spermatogenesis. In this group no positive correlation was observed between the degree of testicular atrophy and intratesticular testosterone concentrations. Intact spermatogenesis was observed in testes with a testosterone content as low as 542 pg/mg tissue.     

Myocardial Effects of Halothane and Isoflurane in Senescent Rats

Background: Aging is associated with marked alterations in myocardial contraction and relaxation, whereas halogenated anesthetics depress myocardial contractility. However, their effects on aging myocardium are unknown.

Methods: Mechanical variables of left ventricular papillary muscles from adult and senescent rats (29[degrees]C; pH 7.40; Ca2+ 1.0 or 0.5 mm; stimulation frequency, 12 pulses/min) were studied. The expression of genes coding for the [alpha]- and [beta]-myosin heavy chain (MHC) and Ca2+-ATPase of the sarcoplasmic reticulum (SR) were studied. The effects of halothane and isoflurane were studied. The inotropic effects were compared under low and high loads, using the maximum unloaded shortening velocity (Vmax) and maximum isometric active force (AF). The lusitropic effects were compared in isotonic and isometric conditions.

Results: Senescent rats had a decrease in contraction and relaxation velocities, associated with a reexpression of [beta]-MHC mRNAs and a decrease in SR Ca2+-ATPase mRNAs. Halothane induced a lower negative inotropic effect in senescent rats (1.5 vol%, AF: 53 +/- 14%vs. 39 +/- 12% of baseline values;P < 0.01) whereas isoflurane induced a similar negative inotropic effect (1.5 vol%, AF: 81 +/- 7%vs. 87 +/- 7% of baseline values; NS). Halothane induced a negative lusitropic effect in isotonic conditions in adult, but not in senescent, rats.     

Myocardial Effects of Halothane and Sevoflurane in Diabetic Rats

Background: Diabetes induces significant myocardial abnormalities, but the effects of halogenated anesthetics on this diseased myocardium remain a matter of debate.

Methods: Left ventricular papillary muscles and triton-skinned cardiac fibers were provided from control and streptozotocin-induced diabetic rats. The effects of halothane and sevoflurane were studied on inotropic and lusitropic responses, under low (isotony) and high (isometry) loads in papillary muscles and then on isometric tension-Ca2+ concentration (pCa) relations obtained in triton-skinned cardiac fibers. Data are presented as mean +/- SD.

Results: Sevoflurane and halothane induced a negative inotropic effect that was more important in diabetic rats (active force: 1.5% halothane, 19 +/- 6 vs. 24 +/- 6% of baseline, P < 0.05; 3.6% sevoflurane, 47 +/- 14 vs. 69 +/- 17% of baseline, P < 0.05). However, when differences in minimum alveolar concentration were considered, no significant difference was observed between groups for halothane. The effects of halothane and sevoflurane on isotonic relaxation and postrest potentiation were not significantly different between groups. In contrast, the decrease in Ca2+ myofilament sensitivity produced by each anesthetic agent was greater in diabetic rats than in control rats (0.65% halothane, -0.15 +/- 0.07 vs. -0.05 +/- 0.04 pCa unit, P < 0.05; 1.8% sevoflurane, -0.12 +/- 0.06 vs. -0.06 +/- 0.04 pCa unit, P < 0.05).     

Halothane and Isoflurane Decrease Alveolar Epithelial Fluid Clearance in Rats

Background: Active sodium transport is the primary mechanism that drives alveolar fluid clearance. In the current study, the effects of exposure to halothane and isoflurane on alveolar fluid clearance in rats were evaluated.

Methods: Rats were exposed to either halothane (0.4% for 6 h or 2% for 2 h) or isoflurane (0.6% for 6 h or 2.8% for 2 h). Reversibility of halothane effects was assessed after 2 h of exposure to 2% halothane. Alveolar and lung liquid clearance were measured by intratracheal instillation of a 5% albumin solution with 1.5 micro Ci of125 I-albumin, during mechanical ventilation with 100% FiO2 and the halogenated agent. The effect of terbutaline (10 sup -4 m) added to the albumin solution was tested after 2 h of exposure to 2% halothane. The increase in protein concentration in the airspaces over 1 h was used to evaluate alveolar liquid clearance. Lung liquid clearance was calculated gravimetrically.

Results: Alveolar liquid clearance rates were decreased by 24%, 30% and 40% compared with controls (P < 0.05) after 2 h of exposure to halothane, 6 h of exposure to halothane, and 6 h of exposure to isoflurane, respectively. After 2 h of exposure to isoflurane, alveolar liquid clearance did not change. In the 2-h halothane exposure group, alveolar liquid clearance returned to the control value 2 h after withdrawal of halothane. Terbutaline increased alveolar liquid clearance by 50% and 89% in the control and 2-h halothane exposure groups, respectively. In all experiments, the same results were obtained for alveolar and lung liquid clearance.     

Minimum Alveolar Concentration of Halothane and Enflurane Are Decreased in Early Pregnancy

Background: Minimum alveolar concentration (MAC) of isoflurane is decreased in early pregnancy but it is not known whether this occurs to the same extent with other inhalational anesthetics. The MAC of halothane and enflurane were compared in pregnant women undergoing elective termination of pregnancy and in nonpregnant women.

Methods: We studied 16 pregnant women scheduled for termination of pregnancy at 8 to 13 weeks gestation and 16 nonpregnant patients undergoing laparoscopic sterilization. Eight patients in each group received halothane and the others received enflurane. After inhalational induction of anesthesia and tracheal intubation, MAC was determined in each patient by observing the motor response to a 10-s, 50-Hz, 80-mA transcutaneous electric tetanic stimulus to the ulnar nerve at varying concentrations of either halothane or enflurane. The end-tidal concentration of inhalational anesthetic was kept constant for at least 15 min before each stimulus and the concentration was varied ultimately in steps of 0.05 vol% (halothane) or 0.10 vol% (enflurane) until a sequence of three alternate responses (move, not move, move) or (not move, move, not move) was obtained. Minimum alveolar concentration for each person was taken as the mean of the two concentrations just permitting and just preventing movement, and MAC for the group was the median of individual MAC values. Confidence intervals were calculated for the percentage decrease in MAC for pregnant women compared with nonpregnant women.

Results: The median (range) MAC of halothane, 0.58 vol% (0.53 to 0.58), and enflurane, 1.15 vol% (0.95-1.25), in the pregnant women were less than those in the nonpregnant women, 0.75 vol% (0.70 to 0.78), P = 0.0005 and 1.65 vol% (1.45 to 1.75), P = 0.0007, respectively. The percentage decrease (95% CI) in MAC for pregnant women was 27% (20 to 27%) for halothane and 30% (24 to 36%) for enflurane.     

Halothane Dissolved in Fat as an Intravenous Anaesthetic to Rats

The anaesthetic properties of a halothane-in-fat solution given either as a single i.v. dose or as a continuous i.v. infusion were investigated in rats. 0.3 ml of a 5% solution of halothane in a fat emulsion was injected i.v. into 15 awake rats. At the end of the 30 s injection, all rats had collapsed from the upright position and showed no response to a firmly applied tail clamp. Breathing usually became shallow and irregular just after injection. Two rats died. In the surviving rats, movement in response to clamping of the tail reappeared after some 30 s (range 15–90 s). The rats regained the upright position after about 100 s, and appeared fully awake about 3 min (range 2–5 min) after injection. Surviving rats behaved normally after the experiment, and gained in weight. They were killed 1–29 days later. The lungs, kidneys, heart, brain and liver had a normal macroscopic and microscopic appearance. In a second set of experiments (n = 9), a 10% solution of halothane was continuously infused i.v. (3.75 (μ min^-1). The anaesthetic depth, as well as the mean arterial pressure, heart rate, respiratory rate and arterial Pco2 and Po2 were similar to values observed during inhalation of halothane in air at an inspired concentration of 1.1%. By doubling the infusion rate, MAP was reduced by 23%. It was easy to adjust anaesthetic depth by changing the infusion rate and recovery was fast.     

Further Studies on Intratesticular Testosterone Concentration in Patients with Disturbed Fertility

Weitere Untersuchungen über die intratestikuläre Testosteron-Konzentration bei Patienten mit Fertilitätsstörungen
32 Patienten mit Azoospermie oder schwerer Oligozoospermie wurden untersucht. Alle Patienten hatten normales Plasma Testosteron. In 10 Fällen fand sich ein pathologisch erhöhter LH-Wert, in 18 Fällen ein erhöhter FSH-Wert. Die Testes wurden morphometrisch untersucht. Je höher der Grad der Atrophie war, um so kleiner waren die Testes und um so mehr Leydigzellen fanden sich in einem gegebenen Gewebestück. Der Volumenanteil an den Testes, den die Leydigzellen einnahmen, korrelierte signifikant mit der testikulären Testosteronkonzentration (r = 0.435, P < 0.001). In der Subgruppe der Patienten mit erhöhten LH-Werten waren die testikulären Testosteronwerte höher als bei den Patienten mit normalem Plasma LH. Zwei Mechanismen für den beobachteten Effekt werden diskutiert: Das Volumen der Hoden, die mit Leydigzellen besetzt sind, ist relativ als Folge der Atrophie angestiegen; es sind einige Fälle vorhanden, bei denen die abnormal hohe LH-Sekretion einen Anstieg der Hoden-Hormon-Werte verursacht.     

Stable Inhibition of Brain Synaptic Plasma Membrane Calcium ATPase in Rats Anesthetized with Halothane

Background: The authors recently showed that plasma membrane Calcium2+ -ATPase (PMCA) activity in cerebral synaptic plasma membrane (SPM) is diminished in a dose-related fashion during exposure in vitro to halothane, isoflurane, xenon, and nitrous oxide at clinically relevant partial pressures. They have now extended their work to in vivo studies, examining PMCA pumping in SPM obtained from control rats decapitated without anesthetic exposure, from rats decapitated during halothane anesthesia, and from rats decapitated after recovery from halothane anesthesia.

Methods: Three treatment groups were studied: 1) C, control rats that were decapitated without anesthetic exposure, 2) A, anesthetized rats exposed to 1 minimum effective dose (MED) for 20 min and then decapitated, and 3) R, rats exposed to 1 MED for 20 min and then decapitated after recovery from anesthesia, defined as beginning to groom. Plasma membrane Calcium2+ -ATPase pumping and Calcium2+ -dependent ATPase hydrolytic activity, as well as sodium-calcium exchanger activity and Sodium sup + -Potassium sup + -ATPase hydrolytic activity, were assessed in cerebral SPM. In addition, halothane effect on smooth endoplasmic reticulum Calcium2+ -ATPase (SERCA) was examined.

Results: Plasma membrane Calcium2+ -ATPase transport of Calcium2+ into SPM vesicles from anesthetized rats was reduced to 71% of control (P < 0.01) compared with 113% of control for the recovered group (NS). No depression by halothane of SERCA activity, sodium-calcium exchanger, or Sodium sup + -Potassium sup + -ATPase activity was noted among the CAR treatment groups.     

Circulatory Effects of Renin-Angiotensin System Antagonists during Halothane Anaesthesia in Hypertensive Rats

The circulatory effects of captopril, an angiotensin I-converting enzyme inhibitor, and saralasin, a competitive angiotensin II antagonist, were studied during halothane anaesthesia in spontaneously hypertensive (SH) rats. Captopril decreased blood pressure significantly in unanaesthetized rats. Pretreatment with indomethacin, a prostaglandin synthesis inhibitor, did not modify the antihypertensive action of captopril. During 1 MAC halothane anaesthesia, the mean arterial pressure (MAP) in unmedicated SH control rats was maintained at a relatively high level (16.2 ± 0.7 kPa, mean ± s.c. mean), while in captopril-treated rats MAP decreased to 8.8 ± 1.1 kPa. Indomethacin somewhat inhibited MAP decrease in the caplopril-medicated group. Saralasin infusion in halothane-anaesthetized rats decreased MAP in the same way as captopril alone. The tolerance to haemorrhagic shock was markedly impaired in rats receiving captopril or saralasin, compared to untreated controls. During halothane anaesthesia, the plasma renin activities in the captopril, captopril + indomethacin, and saralasin groups were significantly higher than in untreated animals. Plasma kininogen was unaffected by any of the medications. The results suggest that the renin-angiotensin system is important in maintaining blood pressure in halothane anaesthesia, and that the tolerance to haemorrhagic shock is particularly impaired by drugs inhibiting the renin-angiotensin system.     

Cerebellar Nitric Oxide Is Increased during Isoflurane Anesthesia Compared to Halothane Anesthesia: A Microdialysis Study in Rats

Background: This study examined the influences of isoflurane versus halothane anesthesia on basal and agonist-stimulated nitric oxide in the cerebellum of intact rats. Nitric oxide was measured using the hemoglobin-trapping method in an in vivo microdialysis technique. This method uses the stoichiometric reaction of nitric oxide with oxyhemoglobin to produce methemoglobin and nitrate; the change in methemoglobin concentration is measured spectrophotometrically to estimate nitric oxide concentration.

Methods: Male Wistar rats were anesthetized with isoflurane (1.4%) or halothane (1.2%), mechanically ventilated and paralyzed (intravenous pancuronium, 1 mg/kg). Microdialysis probes were implanted into the cerebellum. Bovine oxyhemoglobin dissolved in artificial cerebrospinal fluid was pumped through the probe (2 [micro sign]l/ min) and assayed at 15-min intervals. The glutamatergic agonist, kainic acid (KA, 5 mg/kg, intraarterially), was used to stimulate nitric oxide production. NG-nitro L-arginine methyl ester (L-NAME, 40 mg/kg, intravenously) was used to inhibit nitric oxide synthase.

Results: Unstimulated cerebellar nitric oxide concentrations were stable and greater during anesthesia with isoflurane (532 +/- 31 nM; mean +/- SEM) than with halothane (303 +/- 23 nM). L-NAME pretreatment reduced nitric oxide concentrations during isoflurane, but not halothane, anesthesia. Infusion of KA increased nitric oxide in both groups; however, the increase in nitric oxide was significantly greater during isoflurane anesthesia. Pretreatment with L-NAME inhibited the response to KA in both groups.     

Glomerular Filtration Rate during Halothane Anaesthesia and Epidural Analgesia in Combination with Halothane Anaesthesia

Pre- and peroperative determination of glomerular filtration rate (GFR) was performed in nine patients operated during light halothane anaesthesia (group A) and in nine patients operated during epidural analgesia in combination with light halothane anaesthesia (group B). In group A, the mean GFR decreased insignificantly by 7% and the mean arterial blood pressure increased significantly by 10%. In group B, the mean GFR decreased significantly by 19% and the mean arterial blood pressure decreased significantly by 15%. It is suggested that the difference in change in GFR between the two groups was caused by differences in mean arterial blood pressure.     

Effects of Blood Glucose Changes and Physostigmine on Anesthetic Requirements of Halothane in Rats

Background: Although hyper- and hypoglycemia induce neurophysiologic changes, there have been no reports on the effects of blood glucose changes on anesthetic requirements. This study examined the effects of hyper- and hypoglycemia on the minimum alveolar concentration (MAC) of halothane in rats. In addition, based on a previous finding that the level of brain acetylcholine was reduced during mild hypoglycemia, the authors examined the influence of physostigmine on MAC during hypoglycemia.

Methods: In Sprague-Dawley rats, anesthesia was induced and maintained with halothane in oxygen and air. The MAC was determined by observing the response to tail clamping and tested during mild hypoglycemia (blood glucose level, 60 mg/dl) and hyperglycemia (blood glucose level, 300 and 500 mg/dl) induced by insulin and glucose infusion, respectively (experiment 1). The effects of 0.3 and 1.0 mg/kg physostigmine given intraperitoneally on MAC were examined in rats with mild and severe hypoglycemia (blood glucose level, 60 and 30 mg/dl; experiment 2).

Results: In experiment 1, mild hypoglycemia significantly reduced the MAC of halothane (0.76 +/- 0.03%) compared with the control value (0.92 +/- 0.04%), but hyperglycemia did not change MAC. In experiment 2, mild and severe hypoglycemia reduced MAC of halothane in a degree-dependent manner. Physostigmine (1 mg/kg) had no effect on MAC regardless of blood glucose level, but 0.3 mg/kg reduced MAC.     

氟烷七氟醚对酶诱导缺氧大鼠脂过氧化反应的影响（氟烷性肝炎的研究Ⅰ）

雄性ＳＤ大鼠饮用含苯巴比妥（１ｍｇ／ｍｌ）的饮水一周后，随机分为６组，每组６例：ＮＣ，２１％Ｏ２／７９％Ｎ２；ＨＣ，１４％０；１８６％Ｎｅ；ＮＨ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ氟烷；ＨＨ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ氟烷；ＮＳ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ七氟醚；ＨＳ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ七氟醚。吸入时间１ｈ，２４ｈ后测定血浆及肝匀浆中ＭＤＡ、ＳＯＤ、游离琉基的含量。结果ＨＨ、ＮＨ组肝匀浆及血浆中ＭＤＡ、ＳＯＤ的含量均高于其它各组（Ｐ＜０．０１，Ｐ＜０．０５），余各组间均无显著差异（Ｐ＞０．０５）。ＮＨ、ＨＨ组血浆及肝匀浆中游离琉基的含量显著低于其它各组（Ｐ＜０．０１）。提示氟烷所致的肝脂过氧化反应增强的作用可能与其肝毒性有关，而七氟醚无促进肝脏脂过氧化反应增强的作用。     

Immunization with Spermatozoal Peptide Antigens Resulting in Immuno-suppression of Fertility Rates in Female Rats

Immunisierung mit Spermatozoen-Peptid-Antigenen
Peptidantigene mit verhältnismäßig nierigem Molekulargewicht wurden durch Gelfiltrationschromatographie und Dünnschichtchromatographie von Ratten epididymalen Rat-tenspermatozoen isoliert. Nach Koppelung an ein Trägermolekül und Immunisierung von weiblichen Ratten wurde eine signifikante Reduktion der Fertilitätsrate beobachtet. Da diese Peptidantigene ähnlich den Peptidantigenen sind, die bereits von menschlichen Spermatozoen isoliert wurden, kann angenommen werden, daß eine Fertilitätsreduktion auch beim Menschen möglich wäre.     

氟烷七氟醚对酶诱导缺氧大鼠血浆氨基酸谱的影响（氟烷性肝炎的研究Ⅱ）

雄性ＳＤ大鼠饮用含苯巴比妥（１ｍｇ／ｍｌ）的饮水一周后，随机分为６组，每组６例：ＮＣ，２１％Ｏ２／７９％Ｎ２；ＨＣ，１４％Ｏ２／８６％Ｎ２；ＮＳ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ七氟醚；ＨＳ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ七氟醚；ＮＨ，２１％Ｏ２／７９％Ｎ２／１．２ＭＡＣ氟烷；ＨＨ，１４％Ｏ２／８６％Ｎ２／１．２ＭＡＣ氟烷。吸入时间１ｈ、２４ｈ后用高效液相色谱法测定血浆中１１种游离氨基酸的含量。结果ＮＨ与ＨＨ组酪、精、丝、甘、丙、苏、谷氨酰胺含量升高，而支链氨基酸无明显变化。提示氟烷性肝炎的氨基酸谱的变化类似于急性暴发性肝衰竭。     

Ventilation-Perfusion Relationships During Halothane Anaesthesia and Mechanical Ventilation. Effects of Varying Inspired Oxygen Concentration

Ventilation-perfusion relationships (VA/Q), assessed by a multiple inert-gas elimination technique, were studied during halothane anaesthesia and mechanical ventilation at different inspiratory oxygen fractions (FIO2). All nine patients (mean age 65 years, five smokers) displayed unaltered VA/Q distributions with increasing FIO2 from a mean of 29% to 53%. A further increase in FIO2 to a mean of 85% caused an increase in true shunt (VA/Q = 0) from 7 to 10% of cardiac output (P less than 0.01), but no increase in "low" VA/Q (VA/Q less than 0.1). On the return to FIO2 of 29%, true shunt was reduced to the initial level. The findings may fit in with release of hypoxic vasoconstriction when FIO2 is increased to 85%, or the opening up of a certain population of shunt vessels.     

大鼠氟烷性肝炎血、肝中微量元素的测定及其临床意义─—与七氟醚麻醉比较（氟烷性肝炎的研究Ⅳ）

雄性ＳＤ大鼠饮用含苯巴比妥钠（１ｍｇ／ｍｌ）的饮水１周后，随机分为四组，每组８例：ＮＣ，２１％Ｏ＿２／７９％Ｎ＿２；ＨＣ，１４％Ｏ＿２／８６％Ｎ＿２；ＨＳ，１４％Ｏ＿２／８６％Ｎ＿２／１．２ＭＡＣ七氟醚；ＨＨ，１４％Ｏ＿２／８６％Ｎ＿２／１．２ＭＡＣ氟烷。吸入时间为１ｈ。２４ｈ后用原子吸收分光光度法测定血浆及肝匀浆中锌、铜、铁、钙的含量。结果ＨＨ组肝匀浆中铜、锌的含量显著低于对照组（Ｐ＜０．０１），钙离子显著高于对照组（Ｐ＜０．０１），ＨＨ组血浆中铁、铜、锌含量均显著高于对照组（Ｐ＜０．０５）。提示氟烷肝损害过程中铜、铁、锌由损伤肝组织向血浆中释放，这种释放程度与肝损害程度相平行。而且体内微量元素平衡的改变又会加重氟烷性肝损害的发生与发展。     

A Comparative Study of Halothane and Enflurane in Paediatric Outpatient Anaesthesia

Two groups of paediatric patients, consisting of 40 patients each, were studied with regard to anaesthesia induction and recovery. Group H was given halothane and Group E received enflurane. The induction time was similar for the two groups. Enflurane had, on average, a shorter recovery time (17±4 min) than halothane (26±4min) ( P< 0.05).
The mean dose of anaesthetic given, expressed as the product of inspired concentration times minute ventilation, was 2.3±0.2 1 100% halothane and 2.8±0.2 1 100% enflurane. If one assumes that the minimum alveolar concentration (MAC) value for enflurane twice that of halothane, group E received a less potent anaesthetic dose. This might explain the similar induction times, and, in part, the shorter recovery time for enflurane in this study.
No difference was noted between the two agents with regard to post-operative nausea and vomiting or restlessness.