[Preservation of fertility in tumour patients]. / Erhaltung der Fertilität bei Tumorerkrankungen.

The success rates of present-day chemotherapy have provoked a rising awareness with regard to the preservation of quality of life among successfully treated patients. Among other factors, quality of life also implies the capacity to procreate. Unfortunately, both in men and women chemotherapy often irreversibly destroys the production of gametes, thereby causing permanent infertility. By its long-standing experience with the cryopreservation of oocytes, zygotes and embryos, reproductive medicine may offer assistance to those patients. Whereas the storage of cryopreserved semen has now become standard in most institutions, the options for the preservation of fertility in women suffering of malignant disease are still limited. Although cryopreservation of non-fertilized oocytes or of pronuclear cells has been established, both the number of oocytes that can be collected within the short time interval between the first detection of the tumour and the initiation of chemotherapy and the modest developmental capacity per frozen/thawed oocyte markedly limit the option of ovarian hyperstimulation and assisted reproduction. Several successful deliveries of healthy infants have now proven the feasibility of ovarian tissue cryopreservation and later orthotopic transplantation after successful tumour therapy. Further refinement of the techniques involved, but also the formation of multidisciplinary networks are expected to offer a solution for young women struck by cancer but striving to survive and to lead a fulfilled life.

Comparative birth weights of singletons born after assisted reproduction and natural conception in previously infertile women.

BACKGROUND: The possible interference of assisted reproduction techniques (ART) with epigenetic reprogramming during early embryo development has recently sparked renewed interest about the reported lower birth weight among infants born as a consequence of infertility treatments. However, the latter finding so far has relied on the comparison of the birth weight of infants conceived with ART to general population data. A more appropriate comparison group should involve pregnancies in infertile women after natural conception. Therefore, we compared neonatal birth weight data of infants born after various ART treatments, including intrauterine insemination (IUI), with those of previously infertile women achieving pregnancy after sexual intercourse. METHODS: Between August 1996 and March 2004 the data of all infertile women presenting in the infertility unit of the University Women's Hospital of Basel, Switzerland, were collected prospectively, adding up to 995 intact pregnancies and deliveries. The birth weight of all infants resulting from 741 singleton pregnancies were analysed with regard to the patients' characteristics, the occurrence of complications during pregnancy and the type of infertility treatment with which the pregnancies were achieved. RESULTS: Comparison of duration of pregnancy and birth weight of infants born after infertility treatment confirms a shorter pregnancy span and a lower mean birth weight in infants born after IVF and ICSI. If women with pregnancies after ART deliver before term, neonatal birth weight is significantly lower. CONCLUSIONS: There is a specific effect of ART, mainly IVF and ICSI, on both shortening the duration of pregnancy and lowering neonatal birth weight. Both these parameters seem to be interrelated consequences of some modification in the gestational process induced by the infertility treatment. Freezing and thawing of oocytes in the pronucleate stage had a lesser impact on pregnancy span and on neonatal birth weight.

Characterization of an immortalized human granulosa cell line (COV434).

We have investigated the biological characteristics of an immortalized granulosa cell line (COV434), which may be used to study follicular and oocyte maturation in vitro. Granulosa cell function was defined as consisting of three distinct properties: (i) production of 17beta-oestradiol in response to follicle stimulating hormone (FSH); (ii) presence of specific molecular markers of apoptosis enabling the induction of follicular atresia; and (iii) capacity to form intercellular connections with cells surrounding an oocyte. The addition of FSH to the culture medium supplemented with 10% fetal calf serum and 4-androstene-3,17-dione resulted in proliferation of the COV434 granulosa cells and in an increased synthesis of 17beta-oestradiol, indicating the presence of the FSH receptor and cytochrome P450 aromatase in these cells. The receptor for luteinizing hormone (LH) was undetectable. Similar expression of various apoptosis-associated genes was found in COV434 granulosa cells and in granulosa cells of patients stimulated with gonadotrophins for in-vitro fertilization, thus indicating that the immortalized COV434 granulosa cells were able to sustain apoptosis. Multiple intercellular connections were formed during co-culture of COV434 granulosa cells with cumulus cells containing an immature oocyte but not with cumulus cells devoid of an oocyte. Detailed morphological analysis of the intercellular connections with scanning electron microscopy and confocal light microscopy demonstrated the presence of long slender structures. It is concluded that the immortalized human granulosa cell line COV434 may be useful for experimental studies on follicular development.

Prospective evaluation of the ultrasound appearance of the endometrium in a cohort of 1,186 infertile women.

OBJECTIVE: To investigate the effect of differences in endometrial thickness and pattern as visualized with present-day high-resolution transvaginal ultrasound equipment on the outcome of assisted reproductive treatment. DESIGN: Prospective cohort study. SETTING: Two large infertility units in university hospitals. PATIENT(S): The endometrial characteristics of 981 patients during 1,600 assisted reproductive treatment cycles were compared with those of 205 untreated women. In addition, abnormal echogenic patterns of the endometrium were characterized histologically in 44 patients. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Pregnancy rates. RESULT(S): The endometrium was significantly thinner in untreated women and women treated with IUI than in women treated with IVF or intracytoplasmic sperm injection. The exponential proliferation of the endometrium was similar in conception and nonconception cycles. The odds for a successful pregnancy were significantly lower in the presence of a thin endometrium in women treated with IUI but not in women treated with the long stimulation protocol for IVF or intracytoplasmic sperm injection. Singleton pregnancies were more common than multiple pregnancies in patients with thin endometria. CONCLUSION(S): The pregnancy rates of assisted reproductive procedures are influenced only marginally by the degree of endometrial proliferation, and treatment should not be canceled because of inadequate endometrial thickness.

[Desire for children in tumor patients]. / Kinderwunsch bei Tumorpatienten.

After a chemo- and/or radiotherapy not only acute side effects but also longterm side effects do occur. The following longterm side effects are observed: irregularities in the menstrual cycle, early onset of menopause and infertility. They are of special importance to children, teenagers and young adults having survived a malignancy. For young women experiencing a premature menopause a hormone replacement therapy is indicated. The degree of gonadal failure depends on the total dose of cytotoxics, radiation or the combination of both. Alkylating substances are responsible for gonadal failure whereas other cytotoxic agents lead to reversible gonadal dysfunction. An important risk factor for the development of ovarian failure is the woman's age at the time of treatment. A pregnancy in patients with a history of malignancy always is a high risk pregnancy and needs a close follow up. The offspring of cancer survivors do not show a higher rate of chromosomal abnormalities or neoplasms. Before starting a chemo- and/or radiotherapy the patient should be informed about acute and late effects. Men and adolescent boys should be given the opportunity for sperm cryopreservation. It is unclear whether a fertility reserve can be achieved by cryopreservation also in women.

Diagnostic accuracy of computer-assisted sperm motion analysis.

One retrospective and two prospective studies were conducted among 218 couples treated with in-vitro fertilization (IVF) to establish the reproducibility and diagnostic accuracy of computer-assisted sperm analysis (CASA) with swim-up spermatozoa for the prediction of the fertilization rate of oocytes in vitro. Based on the results of a preliminary retrospective analysis in 49 patients, the 'curvilinear velocity' (VCL) was chosen as the most distinctive motion parameter of sperm function and the median was used to represent the entire sperm population. The number of inseminated motile spermatozoa was then adjusted to median VCL during two subsequent prospective studies with clinical IVF. Whereas in the first prospective study (90 couples) the threshold values of VCL with regard to the number of spermatozoa inseminated were based on the results of the preliminary retrospective study (49 couples), in the second prospective study (79 couples) the settings were based on the results of the first prospective study. The reproducibility of CASA was tested by analysing the motion characteristics of spermatozoa at different intervals after termination of swim-up, by repeated analysis of the same video-recording of the incubated spermatozoa by different observers, and by the repeated video-recording of the freshly prepared sperm samples and analysis of both video-recordings by the same observer. Under these conditions the frequency of disagreement between two measurements varied between 2.0 and 8.2%. In both prospective studies the sensitivity of CASA for the prediction of fertilization was high (74.0%), whereas the specificity was low (40.0%). In contrast to successful fertilization, unsuccessful fertilization of oocytes in vitro could not be predicted reliably with CASA. However, the pregnancy rate per cycle among patients with predicted low fertilization rates was significantly lower (5.3%) than in couples with high predicted fertilization rates (24.3%, P < 0.001). Therefore, CASA of washed spermatozoa may still help to identify couples who would benefit more from intracytoplasmic sperm injection (ICSI) than from IVF. A definite threshold level could not be identified for any of the motion parameters to distinguish the motion characteristics of fertilizing and non-fertilizing spermatozoa. Using various algorithms for hyperactivated motility, the percentage of hyperactivated spermatozoa was significantly higher among the successfully fertilizing patients than among the nonfertilizing group. However, the absolute number of hyperactivated spermatozoa added to the oocytes was higher in non-fertilizing couples. Therefore, the lack of fertilization in some patients may be caused by a generalized defect in sperm function rather than by insufficient hyperactivation.

Studies on the origin of redox enzymes in seminal plasma and their relationship with results of in-vitro fertilization.

Glutathione (GSH), GSH peroxidase (GPX), GSH reductase (GRD), superoxide dismutase (SOD) and catalase-like enzyme activity were quantified in seminal plasma from normozoospermic patients, men with known distal ductal occlusion, proven fathers and male partners of couples receiving in-vitro fertilization (IVF) treatment for both male and female causes. Glutathione was non-detectable (< 2.5 microM) in seminal plasma. None of the enzyme activities per unit volume were lower in semen from vasectomized men, suggesting that they did not originate substantially from the testis or epididymis. The strongest relationships between enzyme activities and accessory gland markers were between zinc and GRD (r = 0.678), SOD (r = 0.602) and GPX (r = 0.548), suggesting a largely prostatic origin of these enzymes. Only weak relationships between accessory gland markers and catalase-like activity suggested a multi-glandular source of this enzyme. There was no relationship between the activity of any of the enzymes in the IVF patients with their fertilization rates in vitro or the establishment of pregnancy after IVF. Nor was there any correlation of enzyme activity with the morphology and percentage of motile spermatozoa in semen or with the percentage motility of spermatozoa immediately after swim-up or after overnight incubation. These findings suggest that the protective enzymes in the seminal plasma are contributed largely by the prostate and little by the epididymis, and that in most cases of IVF, they have no major influence on the outcome.

Low multiple pregnancy rates and reduced frequency of cancellation after ovulation induction with gonadotropins, if eventual supernumerary follicles are aspirated to prevent polyovulation.

PURPOSE: Our purpose was to demonstrate the feasibility of the routine aspiration of supernumerary follicles in infertile patients with imminent polyovulation after ovulation induction with gonadotropins and to examine its effect on the frequency of cycle cancellation and on the (multiple) pregnancy rate. METHODS: The data on 796 treatment cycles, performed between 1989 and 1996 on 410 infertile couples, were analyzed retrospectively. From October 1992, whenever necessary, supernumerary ovarian follicles were selectively aspirated transvaginally under ultrasound guidance to prevent the ovulation of more than three follicles. Thereafter, intrauterine insemination was performed. RESULTS: After the adoption of transvaginal ultrasound-guided aspiration of supernumerary follicles into the treatment protocol in October 1992, the number of canceled cycles (P < 0.0001) and the multiple pregnancy rate (P < 0.01) were significantly reduced compared to those previously. The overall pregnancy rate remained stable. No ovarian hyperstimulation syndrome requiring hospitalization was noted, and no complications resulting from the follicle aspiration were registered. CONCLUSIONS: Transvaginal ultrasound-guided aspiration of supernumerary ovarian follicles increases both the efficacy and the safety of ovulation induction with gonadotropins. Because of the limited equipment required, this method represents an alternative for conversion of overstimulated cycles to more costly alternatives such as in vitro fertilization.

Production of reactive oxygen species by and hydrogen peroxide scavenging activity of spermatozoa in an IVF program.

PURPOSE: Reactive oxygen species (ROS) including H2O2 produced by spermatozoa have been suggested, on one hand, to be associated with idiopathic male infertility and, on the other hand, to stimulate certain sperm function leading to fertilization. The influence of ROS on fertilization was investigated in 75 IVF patients by correlating fertilization rates with the production of ROS and the H2O2-scavenging activity of swim-up spermatozoa prepared in parallel with the IVF samples. RESULTS: Low rates of ROS production by the swim-up sperm was detected by the luminol-dependent chemiluminescence assay. They were not correlated with fertilization rates. The hydrogen peroxide scavenging capacity of these spermatozoa, measured as the removal of exogenous H2O2 assayed spectrophotometrically, decreased stepwise in groups of patients achieving higher fertilization rates, suggesting a positive effect of this ROS on fertilization. An alternative explanation of this correlation is plausible in view of the association of both high scavenging activities and poor fertilization rates with poor sperm morphology. CONCLUSIONS: ROS produced by spermatozoa selected by swim-up plays no negative, if not a positive, role in fertilization.

Experience with transvaginal ultrasound-guided aspiration of supernumerary follicles for the prevention of multiple pregnancies after ovulation induction and intrauterine insemination.

OBJECTIVE: To avoid multiple pregnancies caused by ovulation induction. SETTING: Infertile couples treated in the Women's Hospital and the Institute of Reproductive Medicine of the University of Münster, Münster, Germany. DESIGN: The outcome of ovulation induction in patients in whom supernumerary ovarian follicles were aspirated transvaginally was compared with the outcome in patients in whom this intervention was not necessary. In a second randomized prospective study, the efficacy of a low dosage of gonadotropins was compared with a higher dosage. PATIENTS: Two hundred twenty-seven couples suffering from male infertility, unexplained infertility, incipient ovarian failure, and polycystic ovaries. INTERVENTIONS: Aspirations were performed if more than three follicles were sized > 14 mm. MAIN OUTCOME MEASURE: Number of (multiple) pregnancies. RESULTS: During 232 ovulation inductions, 127 aspirations of supernumerary follicles were performed (54.7%). The pregnancy rate (PR) in these cycles was similar to cycles in which aspirations were unnecessary (24.4% versus 21.9%). The efficacy of 75 units of FSH administered daily during the recruitment phase of follicular development was equivalent to 150 units of FSH (PR: 32.4% versus 31.6%), but supernumerary follicles were fewer (26.5% versus 76.3%). Six twins, two triplets (multiple PR: 10.4%), and no ovarian hyperstimulation syndrome occurred. CONCLUSIONS: Transvaginal aspiration of supernumerary follicles does not reduce the PR in ovulation induction. Supernumerary follicles can be avoided by low-dose administration of gonadotropins without compromising the PR.

Spontaneous recrudescence of spermatogenesis in the photoinhibited male Djungarian hamster, Phodopus sungorus.

Photosensitive rodents exposed to inhibitory short photoperiods become insensitive to this environmental factor after prolonged exposure. During the following process of spontaneous recrudescence, the animals that have adapted to the winter season show a return of all seasonal parameters. In the Djungarian hamster, obvious photoperiod-dependent changes are reinitiation of the reproductive organs, a 20-30% increase in body weight, and a moult from whitish fur into brown summer fur. This study was designed to analyze the morphological and endocrinological changes occurring during spontaneous testicular recrudescence in male Djungarian hamsters under prolonged short photoperiods. Two experiments were performed 1) to analyze the time-dependent changes in groups of hamsters exposed to short photoperiods and 2) to observe testicular and humoral changes in individual animals during spontaneous recrudescence. Regrowth of the testes and seminal vesicles did not begin before Week 18 in short photoperiods. While serum testosterone did not increase before Week 24, serum FSH had already returned to normal values from Week 18 onwards. Individual analysis by enzyme histochemistry revealed that 3 beta-hydroxysteroid-dehydrogenase activity in Leydig cells was not restored before testicular weights of more than 400 mg were observed and the first wave of spermatogenesis had reached the stage of elongated spermatids. This indicates that the testicular testosterone production was low until a status of testicular recrudescence had been achieved, at which point the testis showed complete qualitative spermatogenesis and a restoration of the Sertoli cell actin filaments. These data suggest that the process of early spontaneous recrudescence in male Djungarian hamsters appears to be initiated by the restoration of serum FSH rather than by testosterone.

[Recombinant growth hormone for support of ovarian gonadotropin treatment in a hypophysectomized patient: a case-control study]. / Rekombinantes Wachstumshormon zur Unterstützung der ovariellen Gonadotropinbehandlung bei einer hypophysektomierten Patientin: ein Fallbeispiel mit Eigenkontrolle.

In a patient, suffering of apituitarism after the surgical removal of a cranyopharyngeoma at the age of 14, was treated with various doses of human urinary gonadotropin preparations for in vitro fertilization and embryo transfer. The first five treatments were performed without the additional administration of recombinant growth hormone, but due to the administration of increasing doses of exogenous gonadotropins a pregnancy was finally achieved leading to the birth of a healthy girl. Later, as the couple desired a second baby, the treatment was repeated using a low dose of gonadotropins in combination with recombinant growth hormone. This combined treatment was immediately successful, leading to the birth of a healthy boy. The present communication offers a complete survey of the existing literature about the use of recombinant growth hormone in support of ovarian stimulation with gonadotropins. The ongoing controversy is caused by the lack of an established methodology for the diagnosis of growth hormone deficiency. Whereas the efficacy of the additional use of recombinant growth hormone in support of ovarian stimulation with gonadotropins is established in patients without any endogenous growth hormone secretion, its use in patients with less defined hormonal disturbances remains controversial.

Peroxidase-positive round cells and microorganisms in human semen together with antibiotic treatment adversely influence the outcome of in-vitro fertilization and embryo transfer.

Human semen contains not only spermatozoa but also other cells routinely differentiated as being peroxidase-positive (e.g. leucocytes) and peroxidase-negative (e.g. immature germ cells and lymphocytes) cells. Considerable uncertainty exists about their role in male fertility. To assess the clinical value of both parameters, and of microorganisms in semen, 391 treatments with in-vitro fertilization and embryo transfer were analysed retrospectively, and the concentrations of both peroxidase-positive and -negative cells, together with the presence of microorganisms in semen, were compared with both the fertilization and pregnancy rates. The data indicate that the results of treatment were affected only by excessively elevated concentrations of peroxidase-positive cells (> 6 x 10(6)/ml) and only marginally by the presence of microorganisms in the semen. The pregnancy rate after in-vitro fertilization and embryo transfer was not improved by antibiotic treatments preceding gamete recovery by several weeks. The increased presence of peroxidase-negative cells (e.g. germ cells) in semen was not associated with a significant change in the pregnancy rate. However, the concentration of peroxidase-negative cells in semen correlated significantly with sperm numbers (p < 0.01), sperm concentration (p < 0.01), and normal morphology rates (p < 0.01). It is concluded that short-term antibiotic treatment of asymptomatic patients before assisted reproduction should be handled with caution. The widespread view that peroxidase-negative cells in semen are harmful is rejected.

Pulsatile subcutaneous versus bolus intramuscular gonadotrophin administration after pituitary suppression with a long-acting gonadotrophin-releasing hormone analogue: a controlled prospective study.

The potential advantages of pulsatile s.c. administration instead of daily bolus i.m. administration of human urinary gonadotrophin preparations were tested after the administration of a long-acting gonadotrophin-releasing hormone (GnRH) analogue within a programme for in-vitro fertilization (IVF) and embryo transfer. First, the pharmacokinetic properties of human urinary gonadotrophins were analysed with immunological and biological methods, both during bolus i.m. injections and during pulsatile s.c. administration. Second, a prospective randomized controlled study was performed in 75 patients undergoing IVF/embryo transfer in whom the effects of pulsatile s.c. administration were compared with the effects of single daily bolus i.m. injections of the same gonadotrophin preparation. The results showed that neither method of gonadotrophin administration induced measurable changes in the serum concentration of luteinizing hormone (LH). Both oestradiol and androstenedione concentrations were slightly lower during pulsatile s.c. gonadotrophin administration, suggesting that this method of gonadotrophin administration results in less LH occupying the ovarian LH receptors. Pulsatile s.c. gonadotrophin administration resembles a continuous infusion of follicle-stimulating hormone (FSH). Significant fluctuations in the serum concentrations of FSH were observed during single daily bolus i.m. administration of human urinary gonadotrophins, but the pregnancy rate of IVF/embryo transfer per cycle after pulsatile s.c. administration was not significantly better than after the daily bolus i.m. injection of gonadotrophins (42.1 versus 37.2%). It is concluded that pulsatile s.c. administration of gonadotrophins instead of single daily injections does not improve the pregnancy rate in IVF/embryo transfer.

Predictive parameters for ovarian response to hyperstimulation with exogenous gonadotropins after suppression of gonadotropin secretion of the pituitary using a long-acting GnRH agonist.

Individually adapted gonadotropin dosage is more successful than standardized schemes for ovarian stimulation prior to in vitro fertilization and embryo transfer. Unfortunately, differences in ovarian response can not be predicted reliably. In order to develop predictive parameters for ovarian response the data from 99 cycles in 69 patients were analysed retrospectively. Before initiating ovarian stimulation for in vitro fertilization, an untreated menstrual cycle was examined using a commonly used endocrinological screening protocol. The ovaries were then stimulated with exogenous gonadotropins after previous suppression of endogenous gonadotropin secretion using a long-acting GnRH-analogue. The predictive value of this endocrinological screening protocol for ovarian response was evaluated. Ovarian response was defined as the logarithmically transformed ratio of the serum estradiol concentration at ovulation induction, divided by the number of ampoules of exogenous gonadotropins administered. Comparison of the various hormone characteristics with ovarian response led to identification of two distinct groups of patients showing reduced ovarian response: those with elevated serum levels of FSH on the third cycle day (> 9 units/l, P < 0.0001), and those with elevated serum levels of estradiol on the third cycle day (> 190 pmol/l, P < 0.02). Patients with high serum levels of TSH in the TRH test responded poorly to ovarian stimulation (P < 0.05), but also showed significantly higher serum concentrations of FSH (P < 0.01). No parameter correlated positively with ovarian response.

Subnormal sperm parameters in conventional semen analysis are associated with discrepancies between fertilization and pregnancy rates in in-vitro fertilization and embryo transfer.

Three hundred and twenty-eight consecutive treatment cycles in 168 couples were analysed retrospectively in order to examine the influence of conventional semen analysis results on the outcome of in-vitro fertilization and embryo transfer with respect to the occurrence of both fertilizations and pregnancies. All treatments were performed under maximally standardized and controlled conditions. Each of the three main determinants of the spermiogram, namely the concentration, motility and morphology of sperm in seminal plasma, was of significant importance for fertilization and subsequent pregnancy. Best correlations were achieved by counting the number of progressively (a+b) motile sperm and the number of normally formed sperm in seminal plasma. The pregnancy rate was reduced significantly in cases in which the sperm concentration was < 10 x 10(6) ml-1 (P < 0.01), or in which there was < 40% progressively motile sperm (P < 0.001), or < 30% normally formed sperm (P < 0.001). If more than one parameter in the spermiogram was abnormal, the fertilization rate depended mainly on the most disturbed sperm parameter. The implantation rate as well as the pregnancy rate was reduced significantly in patients with low progressive sperm motility and normal morphology rates. The difference could only be attributed partially to the lower number of embryos replaced. In conclusion, subnormal sperm quality seems to interfere with developmental stages beyond the process of fertilization.

Interdependent influence of follicular fluid oestradiol concentration and motility characteristics of spermatozoa on in-vitro fertilization results.

Methods are presented for an objective assessment of the quality of both gametes in an in-vitro fertilization programme. The concentrations of oestradiol and progesterone in follicles whose oocytes did or did not fertilize, were measured and assessed as potential markers of oocyte maturity. There was no difference in the mean concentrations of either steroid in follicular fluid of fertilized and unfertilized oocytes. However, a highly significant inverse correlation was observed between the oestradiol concentration in follicles of oocytes becoming fertilized and the number of spermatozoa added for fertilization (P less than 0.001). Follicular fluid concentrations of progesterone did not correlate with the number of inseminated spermatozoa. The correlation between follicular oestradiol concentrations and the number of spermatozoa needed for fertilization was then used to identify movement characteristics of spermatozoa in the culture medium which were relevant for fertilization. Sufficient numbers of spermatozoa having specific values of head cross frequency, lateral head displacement, linearity and curvilinear velocity were critical for the occurrence of fertilization in vitro.

Pattern of pineal melatonin concentrations during prolonged exposure to short photoperiods in photosensitive and photoinsensitive Djungarian hamsters.

In the Djungarian hamster (Phodopus sungorus) there is strong evidence that the nightly decompression or lengthening, respectively, of the pineal melatonin pattern is involved in conveying the inhibitory influence of short photoperiods. Some hamsters, however, are insensitive to photoinhibitory influences; other late-responding hamsters show a delayed reaction of several months. The daily pattern of pineal melatonin proves that the mechanisms determining long- or short-day patterns become effective in the morning and evening hours when melatonin concentrations of photoinhibited hamsters are clearly elevated, while those of long-day hamsters are reduced to negligible low values. At two decisive time points in the morning and evening, male and female early-responding photosensitive hamsters were killed after 5, 10, 15, and 20 weeks in short photoperiods, nonresponding hamsters after 10 and 20 weeks, and late-responding after 20 weeks. In all early-responding hamsters changes in gonadal stage, body weight, and pelage color corresponded to the decompression of the nightly melatonin pattern. During prolonged exposure to short photoperiods a decrease of mean melatonin concentrations in the morning and an increase of evening concentrations was observed in both sexes. The lengthening of nightly elevated melatonin concentrations was missing in photoinsensitive hamsters. In late-responding hamsters this decompression seems to be delayed, as melatonin concentrations of female late responders indicate. In conclusion, the lengthening of the melatonin pattern seems to predict a photoperiodic reaction of the effector system. The lengthened pattern of photosensitive hamsters may not be unchangeable, as it may be subjected to modifications during prolonged exposure to short photoperiods.

Effect of different amino acidic pretreatments that protect the kidney against papillary necrosis induced by bromoethylamine on differential distribution of renal nonprotein sulfhydryls.

Content of nonprotein sulfhydryls (NPSH) was found to be higher in rat renal cortex than in external medulla and papilla. Administration of bromoethylamine (BEA), at a dose that produces extensive papillary necrosis and minor effects in the other renal segments, induced a significant reduction in NPSH levels of renal cortex and external medulla, with no changes in the papilla. Treatment with N-acetyl-L-cysteine (NAC) elicited an increase in papillary NPSH and a decrease in the cortex, with opposite changes being observed with an amino acid mixture of glutamine, glycine, and cystine (AM). Similar results were found in animals pretreated with NAC or AM prior to BEA intoxication. These pretreatments protect the cortex, external medulla, and papilla from the necrosis induced by BEA. It is suggested that protection of BEA-induced renal necrosis by NAC or AM pretreatments might be due to different mechanisms, with NPSH playing direct or indirect roles, respectively.

Effects of bovine mammary alpha-lactalbumin on hyperactivation and sperm-zona pellucida binding of mouse spermatozoa.

The effects of bovine mammary alpha-lactalbumin on the motility and zona-binding characteristics of mouse sperm were investigated. Two properties of sperm associated with capacitation, hyperactivated motility, and the ability of sperm to bind to the zona pellucida of oocytes were shown to be suppressed by alpha-lactalbumin. These inhibitory effects were not accompanied by changes in the percentage of motile cells or by differences in the velocity parameters of the hyperactivated and non-hyperactivated spermatozoa. Bovine serum albumin prevented and reversed the alpha-lactalbumin-induced suppression of hyperactivation. Sperm-zona pellucida binding was partially restored by lowering the alpha-lactalbumin concentration in the medium in which sperm were allowed to bind to the zona pellucida. The results suggest that mouse sperm are decapacitated by bovine mammary alpha-lactalbumin. The counteracting effect of bovine serum albumin to the suppressive action of alpha-lactalbumin on the flagellum suggests the involvement of a mechanism different from the action of alpha-lactalbumin on the sperm head inhibiting binding to the zona pellucida.