Variation in partial direct costs of treating clinical mastitis among 37 Wisconsin dairy farms

The objective of this observational study was to describe variations in partial direct costs of clinical mastitis (CM) treatments among 37 dairy herds using data obtained from herd management records. Animal health and drug purchase records were retrospectively collected from 37 Wisconsin dairy herds for a period of 1 yr. Each farm was visited to verify case definitions, recording accuracy, and detection criteria of CM cases. Descriptive statistics were used to summarize cost of drugs and milk discard. Differences in costs among protocols, intramammary (IMM) products, parities, days in milk, and recurrence were analyzed using ANOVA. Of 20,625 cases of CM, 31% did not receive antimicrobial treatment. The average cost of drugs and milk discard (including cases that were not treated) was $192.36 ± 8.90 (mean ± SE) per case and ranged among farms from $118.13 to $337.25. For CM cases treated only with IMM antimicrobials, milk discard accounted for 87% of total costs and was highly influenced by duration of therapy. Differences in costs were observed among parities, recurrence, and stage of lactation at case detection. Eight different treatment protocols were observed, but 64% of cases were treated using only IMM antimicrobials. Treatment costs varied among protocols; however, cases treated using both IMM and injectable antimicrobials as well as supportive therapy had the greatest costs as they were also treated for the longest duration. Ceftiofur was used for 82% of cases that received IMM antimicrobials while ampicillin was used for 51% of cases treated using injectable antimicrobials. With the exception of ceftiofur and pirlimycin IMM products, many IMM products were given for durations that exceeded the maximum labeled duration. For cases treated using only IMM therapy, as compared with observed costs, we estimated that partial direct costs could be reduced by $65.20 per case if the minimum labeled durations were used. Overall, partial direct costs per case varied among herds, cow factors, and treatment protocols and were highly influenced by the duration of therapy.

Quantification of antimicrobial usage in adult cows and preweaned calves on 40 large Wisconsin dairy farms using dose-based and mass-based metrics

Use of antimicrobials in animal agriculture is under increasing scrutiny, but the quantity of antimicrobials used on large US dairy farms has not been evaluated using data from large farms and different metrics. This study investigated total antimicrobial usage (AMU) in adult dairy cows and preweaned calves (PWC) and contrasted 2 metrics used for measurement of AMU. Wisconsin dairy farms were eligible if they had >250 lactating cows, maintained computerized animal health records, and were willing to allow researchers access to treatment records. Animal health data for a 1-yr period was retrospectively collected from computerized records, and a farm visit was performed to verify case definitions and recording accuracy. Both dose-based (animal daily doses; ADD) and mass-based (total mg of antimicrobials per kg of body weight; BW) metrics were calculated at the herd, cow, and PWC levels. Descriptive statistics for AMU were examined for both age groups. Mean AMU was compared among active ingredients and route of usage using ANOVA models that included farm as a random variable. At enrollment, farms (n = 40) contained approximately 52,639 cows (mean: 1,316 ± 169; 95% CI: 975, 1657) and 6,281 PWC (mean: 180 ± 33; 95% CI: 112, 247). When estimated using ADD, total herd AMU was 17.2 ADD per 1,000 animal-days (95% CI: 14.9, 19.5), with 83% of total herd-level AMU in adult cows. When estimated using the mass-based metric, total herd AMU was 13.6 mg of antimicrobial per kilogram of animal BW (95% CI: 10.3, 17.0), with 86% of total AMU used in adult cows. For cows, 78% of total ADD (15.8 ADD per 1,000 cow-d) was administered as intramammary (IMM) preparations. In contrast, when AMU was estimated using a mass-based metric, IMM preparations represented only 24% of total AMU (12.1 mg of antimicrobial/kg of cow BW). For cows, ceftiofur was the primary antimicrobial used and accounted for 53% of total ADD, with 80% attributed to IMM and 20% attributed to injectable treatments. When estimated using a mass-based metric, ampicillin was the predominant antimicrobial used in cows and accounted for 33% of total antimicrobial mass per kilogram of BW. When AMU was estimated for PWC using ADD, injectable antimicrobials represented 79% of total usage (28.3 ADD per 1,000 PWC-d). In contrast, when AMU was estimated for PWC using a mass-based metric, injectable products represented 42% of total AMU, even though more farms administered antimicrobials using this route. When AMU in PWC was summarized using ADD, penicillin represented 32% of AMU, and there were no significant differences in ADD among ampicillin, oxytetracycline or enrofloxacin. When a mass-based metric was used to estimate AMU in PWC, oral products (sulfadimethoxine and trimethoprim-sulfa) represented more than half of the total AMU given to this group. Overall, these results showed that choice of metric and inclusion of different age groups can substantially influence interpretation of AMU on dairy farms.

Molecular mimicking of C-terminal phosphorylation tunes the surface dynamics of CaV1.2 calcium channels in hippocampal neurons

L-type voltage-gated Ca_V1.2 calcium channels (Ca_V1.2) are key regulators of neuronal excitability, synaptic plasticity, and excitation-transcription coupling. Surface-exposed Ca_V1.2 distributes in clusters along the dendrites of hippocampal neurons. A permanent exchange between stably clustered and laterally diffusive extra-clustered channels maintains steady-state levels of Ca_V1.2 at dendritic signaling domains. A dynamic equilibrium between anchored and diffusive receptors is a common feature among ion channels and is crucial to modulate signaling transduction. Despite the importance of this fine regulatory system, the molecular mechanisms underlying the surface dynamics of Ca_V1.2 are completely unexplored. Here, we examined the dynamic states of Ca_V1.2 depending on phosphorylation on Ser-1700 and Ser-1928 at the channel C terminus. Phosphorylation at these sites is strongly involved in Ca_V1.2-mediated nuclear factor of activated T cells (NFAT) signaling, long-term potentiation, and responsiveness to adrenergic stimulation. We engineered Ca_V1.2 constructs mimicking phosphorylation at Ser-1700 and Ser-1928 and analyzed their behavior at the membrane by immunolabeling protocols, fluorescence recovery after photobleaching, and single particle tracking. We found that the phosphomimetic S1928E variant increases the mobility of Ca_V1.2 without altering the steady-state maintenance of cluster in young neurons and favors channel stabilization later in differentiation. Instead, mimicking phosphorylation at Ser-1700 promoted the diffusive state of Ca_V1.2 irrespective of the differentiation stage. Together, these results reveal that phosphorylation could contribute to the establishment of channel anchoring mechanisms depending on the neuronal differentiation state. Finally, our findings suggest a novel mechanism by which phosphorylation at the C terminus regulates calcium signaling by tuning the content of Ca_V1.2 at signaling complexes.

Using surface force apparatus, diffusion and velocimetry to measure slip lengths

Determining the slip lengths for liquids flowing close to smooth walls is challenging. The reason lies in the fact that the scales that must be addressed range between a few and hundreds of nanometres. Several techniques have been used over the last few years. Here, we consider three of them based on surface force apparatus, diffusion and velocimetry, respectively. The descriptions offered here incorporate recent instrumental progress made in the field.

Nanoscale flow on a bubble mattress: effect of surface elasticity

We present an experimental study of the elastic properties of a superhydrophobic surface in the Cassie regime, due to the gas bubbles trapped at the liquid-solid interface. We use a surface force apparatus to measure the force response to an oscillating drainage flow between a sphere and the surface. We show that the force response allows to determine the surface elasticity without contact, using the liquid film as a probe. The elasticity of the bubble mattress is dominated by the meniscii stiffness, and its determination enables us to probe the shape of these meniscii. Another effect of surface elasticity is to decrease the viscous friction. We show that this effect can be wrongly attributed to rate dependant boundary slippage if elastohydrodynamics is not taken into account.

Boundary slip on smooth hydrophobic surfaces: intrinsic effects and possible artifacts

We report an accurate determination of the hydrodynamic boundary condition of simple liquids flowing on smooth hydrophobic surfaces using a dynamic surface force apparatus equipped with two independent subnanometer resolution sensors. The boundary slip observed is well defined and does not depend on the scale of investigation from one to several hundreds of nanometers, nor on shear rate up to 5 x 10(3)s(-1). The slip length of 20 nm is in good agreement with theory and numerical simulations concerning smooth nonwetting surfaces. These results disagree with previous data in the literature reporting very high boundary slip on similar systems. We discuss possible origins of large slip length on smooth hydrophobic surfaces due to their contamination by hydrophobic particles.

Differential effects of gonadotropin-releasing hormone (GnRH) pulse frequency on gonadotropin subunit and GnRH receptor messenger ribonucleic acid levels in vitro

The hypothalamic hormone, GnRH, is released and transported to the anterior pituitary in a pulsatile manner, where it binds to specific high-affinity receptors and regulates gonadotropin biosynthesis and secretion. The frequency of GnRH pulses changes under various physiological conditions, and varying GnRH pulse frequencies have been shown to regulate differentially the secretion of LH and FSH and the expression of the gonadotropin alpha, LH beta, and FSH beta subunit genes in vivo. We demonstrate differential effects of varying GnRH pulse frequency in vitro in superfused primary monolayer cultures of rat pituitary cells. Cells were treated with 10 nM GnRH pulses for 24 h at a frequency of every 0.5, 1, 2, or 4 h. alpha, LH beta, and FSH beta messenger RNA (mRNA) levels were increased by GnRH at all pulse frequencies alpha and LH beta mRNA levels and LH secretion were stimulated to the greatest extent at a GnRH pulse frequency of every 30 min, whereas FSH beta mRNA levels and FSH secretion were stimulated maximally at a lower GnRH pulse frequency, every 2 h. GnRH receptor (GnRHR) mRNA levels also were increased by GnRH at all pulse frequencies and were stimulated maximally at a GnRH pulse frequency of every 30 min. Similar results were obtained when the dose of each pulse of GnRH was adjusted to maintain a constant total cumulative dose of GnRH over 24 h. These data show that gonadotropin subunit gene expression is regulated differentially by varying GnRH pulse frequencies in vitro, suggesting that the differential effects of varying GnRH pulse frequencies on gonadotropin subunit gene expression occur directly at the level of the pituitary. The pattern of regulation of GnRHR mRNA levels correlated with that of alpha and LH beta but was different from that of FSH beta. This suggests that alpha and LH beta mRNA levels are maximally stimulated when GnRHR levels are relatively high, whereas FSH beta mRNA levels are maximally stimulated at lower levels of GnRHR expression, and that the mechanism for differential regulation of the gonadotropins by varying pulse frequencies of GnRH may involve levels of GnRHR. Furthermore, these data suggest that the mechanisms whereby varying GnRH pulse frequencies stimulate alpha LH beta, and GnRHR gene expression are similar, whereas the stimulation of FSH beta mRNA levels may be different.

Regulation of rat pituitary gonadotropin-releasing hormone receptor mRNA levels in vivo and in vitro

The recent isolation of cDNAs encoding the rat pituitary gonadotropin-releasing hormone receptor (GnRHR) allows studies of the regulation of the synthesis of the GnRHR and its relationship to reproductive function. Analyses of the regulation of GnRHR mRNA levels in the rat pituitary in vivo revealed a progressive increase in levels to 2.0 +/- 0.2-fold after ovariectomy (OVX) and 5.2 +/- 1.3-fold after castration (CAST) (21 days post-operative), compared to intact adult female and male controls, respectively. Replacement therapy with 17 beta-estradiol benzoate in 21-day post-OVX female rats resulted in a marked decrease in GnRHR mRNA levels by 7 days, compared to controls. In contrast, therapy with testosterone propionate in 21-day post-CAST male rats resulted in only a modest decrease in GnRHR mRNA levels. Thus, manipulation of the reproductive endocrine system in vivo results in alterations in GnRHR synthesis at the pretranslational level, which parallel known changes in cell surface gonadotropin-releasing hormone (GnRH) binding activities. The treatment of superfused primary monolayer cultures of rat pituitary cells with hourly pulses of GnRH (10 nM, 6 min/h) resulted in a marked increase in GnRHR mRNA levels (12.8 +/- 4.3-fold compared to untreated cells). In contrast, treatment of cultured cells with continuous GnRH caused no change in GnRHR mRNA levels. These in vitro data show homologous regulation of GnRHR gene expression by GnRH, and suggest that the changes in GnRHR gene expression observed in vivo may be attributable at least in part to changes in the pattern of hypothalamic GnRH secretion.

Sensitivity of Sertoli and Leydig cells to xenobiotics in in vitro models

Different chemicals are known to cause testicular damage in the human male and experimental animals. However, the ability to assess the potential and mechanism of action leading to chemically-induced damage in men has been hampered by a lack of good predictive models. Although many of these chemicals were found to impair reproductive capacity in various laboratory animals, only some have caused reproductive damage in men. Mammalian spermatogenesis takes places within the avascular seminiferous tubules of the testis. Specialized tight junctions, which form between adjacent Sertoli cells at the time of puberty, divide the tubular space into the basal and adluminal compartments, and create a "blood-testis" barrier that restricts passage of substances and ions from the circulation. Thus, the completion of meiosis and post-meiotic germ cell differentiation, which take place in the adluminal compartment, are isolated from circulating substances unable to cross the blood-testis barrier. It seems feasible, therefore, that damage to the germ cells induced by testicular toxicants may be mediated through other cells in the testis such as the Sertoli, peritubular, or Leydig cells. A recently developed two-compartment system for culture of testicular cells can simulate, to some degree, the normal physiologic conditions. In principle, Sertoli cells isolated from mammalian testes are cultured on a permeable support (that is millipore filter) between two fluid compartments. They form a highly polarized epithelial layer with characteristic tight junctions that restrict the passage of substances between the two compartments, in analogy to the blood-testis barrier. We believe this system provides an excellent in vitro model for determining the ability of chemicals to: a) alter the permeability of the blood-testis barrier, b) impair the secretory function of Sertoli cells, or c) affect their viability, all of which could indirectly affect the germ cells. We have utilized this system for examining the effects of cadmium chloride (CdCl2) and other toxic substances known to affect the testis. The Leydig cell toxicity was investigated in testicular perfusion system or cultures of isolated Leydig cells.

Effect of cadmium chloride on transepithelial electrical resistance of Sertoli cell monolayers in two-compartment cultures--a new model for toxicological investigations of the "blood-testis" barrier in vitro

The effect of various doses (0.75-24 microM) of cadmium chloride (CdCl2) on the development of intercellular tight junctions by immature rat Sertoli cells (Sc) was investigated in vitro using the two-compartment culture system. The status of tight junctions was monitored by repeated measurements of the transepithelial electrical resistance (TER). For defining the specificity of CdCl2 effects, the TER changes were correlated with Sc secretory activity (immunoactive inhibin), the cell number (DNA content), and viability (MTT test). The effects of CdCl2 depended on the concentration of the toxicant as well as on the onset and duration of exposure (4 and 18 hr on Day 1 or 5 of culture). The observed effects could be divided into four categories: (1) At highest doses employed, the TER values decreased significantly and irreversibly during 13 days of culture, and the decrease was accompanied by a significant and irreversible drop in inhibin secretion, cell viability, and cell number. (2) Within a narrow range of doses, the irreversible, or only partially reversible, decrease of TER was accompanied by a transient decrease, or no change, of the secretory activity and no significant changes in Sc cell number and/or viability. (3) With still lower doses, the TER values rapidly decreased and then returned to control level within 3-4 days. In this group, no changes in either inhibin secretion or cell viability were observed. (4) Exposure to the lowest doses of CdCl2 caused a delayed, but significant increase in TER. This increase was not accompanied by noticeable changes in other parameters evaluated. These data suggest that CdCl2 may selectively compromise, at least in vitro, the development and maintenance of the inter-Sc tight junctions, without affecting the secretory activity or the cell number and viability. However, increasing cumulative doses of CdCl2 (concentration multiplied by the time of exposure) led to decreased inhibition secretion and cell viability and then, finally, to irreversible cell damage and death. We believe that the experimental model and approach reported in this paper should be very useful for investigating the mechanism of action of known or potential testicular toxicants, particularly those suspected to compromise the integrity of the "blood-testis" barrier.

Effects of recombinant human inhibin and testosterone on gonadotropin secretion and subunit mRNA in superfused male rat pituitary cell cultures stimulated with pulsatile gonadotropin-releasing hormone

Effects of recombinant human inhibin (rh inhibin) and testosterone on follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion and mRNA levels of gonadotropin subunits were investigated in superfused male rat pituitary cell cultures. During superfusion, the cells were stimulated with gonadotropin-releasing hormone (GnRH) pulses (10 nM, 6 min/h) and exposed to rh inhibin (2 ng/ml) and/or testosterone (10 nM) for up to 20 h. The concentrations of FSH and LH were measured in effluent media by radioimmunoassay (RIA), and subunit mRNAs were determined by Northern blot hybridizations using rat FSH beta, LH beta and alpha genomic and cDNA probes. Rh inhibin suppressed the secretion of FSH (30-40% of control) and the secretion of LH to 50-60% of control, but inhibited only FSH beta mRNA (to non-detectable levels). Testosterone alone suppressed the release of LH to 50% of control, whereas FSH release was increased to 130-160% (P less than 0.05) of control. This increase was due to higher interpulse values without significant changes in the pulse amplitude. Also FSH beta mRNA level was increased (1.5-fold, P less than 0.05) but only after 17-20 h of treatment. On the other hand, testosterone had no effect on LH beta and alpha subunit mRNA levels. Testosterone in combination with rh inhibin showed an inhibitory effect on LH beta mRNA; however, the pattern of LH release was not significantly different from that observed with rh inhibin or testosterone alone. Combined effects of testosterone and rh inhibin on FSH secretion and FSH beta mRNA were similar to those observed with rh inhibin alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cyclic AMP and phorbol ester on transepithelial electrical resistance of Sertoli cell monolayers in two-compartment culture

The effects of dibutyryl cyclic AMP [Bu)2cAMP) and phorbol ester (TPA), in the absence or presence of follicle-stimulating hormone (FSH) and/or testosterone, on the development of tight junctions by immature rat Sertoli cells (Sc) were investigated in vitro using the two-compartment culture system. The tight junction status was evaluated by repeated measurements of transepithelial electrical resistance (TER). Untreated cell monolayers developed stable TER of approximately 120 omega cm2 during 3 days of culture. Continuous presence of FSH (200 ng/ml) from day 1 onward significantly increased the TER up to approximately 300 omega cm2 after a transient (24-36 h) delay. The initial delay was prolonged to 3-4 days by the addition of 1-methyl-3-isobutylxanthine (MIX) (0.2 mM), whereas the subsequent increase of TER was significantly potentiated by the concomitant presence of testosterone (10 microM). Cholera toxin (CHT; 10 ng/ml) and forskolin (FR; 50 microM) mimicked these FSH effects. (Bu)2cAMP, at concentrations which maximally stimulated immunoactive inhibin secretion (100-500 microM), inhibited the initial TER increase and significantly decreased the TER level when added on days 1 and 5 of culture, respectively. In contrast, low concentrations of (Bu)2cAMP (4-20 microM) consistently stimulated the TER development, mimicking the stimulatory phase of FSH action. TPA (100 nM) alone had no effect on TER development, but potentiated the stimulatory effect of testosterone in a manner similar to FSH, CHT, FR or low concentrations of (Bu)2cAMP. These results demonstrate, for the first time, a concentration-dependent, dual effect of exogenous cAMP on the Sc function.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural characteristics of immature rat Sertoli cells in vivo and in vitro

The structural properties of pelleted prepubertal Sertoli cells (pre-culture pelleted cells) from 19-day-old rats and of similar cells cultured for 7 days were compared with Sertoli cells from the intact animal (testis tissue from 19- and 26-day-old rats, the in vivo groups). Sertoli cells from freshly isolated pellets and those cultured for 7 days were similar in cell and nuclear volumes to their in vivo counterparts. Cell volumes, organelle volumes, and organelle volume densities of newly isolated Sertoli cells were similar to those of sectioned cells taken from the 19-day-old in vivo group, indicating that the procedure for isolation does not grossly alter Sertoli cells. Mean height of cells cultured for 7 days was significantly lower than that of cells from intact animals at 19 and 26 days of age. In vivo, Sertoli cells of 26-day-old animals displayed increased organelle volumes and organelle surface areas compared with those from 19-day-old animals; volume densities and surface densities remained relatively constant, indicating that in vivo, organelle growth is in proportion to growth of the cell. Most organelle volume and surface densities were not significantly different when 19-day-old in vivo cells and pre-culture pelleted cells were compared. Many organelle volume and surface density values were significantly less in cells grown in culture for 7 days as compared to freshly isolated pelleted cells. After 7 days of culture, most Sertoli cell organelles were significantly less in both volume density and surface density, as compared to the in vivo cell groups (19 or 26 day). This indicates that in vitro the organelles do not develop in proportion to the growth of the cell. After 7 days in culture, the absolute volumes and surface areas of the organelles remained generally unchanged as compared to cells from 19-day-old animals. The data show that Sertoli cells grow in volume in vitro like their in vivo counterparts; however, their subcellular features, although well maintained, do not develop in proportion to the cell. This suggests that short-term cultures are a more ideal system in which to study biochemical responses. Also, cultured prepubertal Sertoli cells are most appropriately used to study prepubertal Sertoli cell function. This is the first study to quantify developmental changes in Sertoli cell structure in vivo as well as to compare them with cellular changes occurring in vitro.

Regulation of transepithelial electrical resistance in two-compartment Sertoli cell cultures: in vitro model of the blood-testis barrier

The effects of FSH, testosterone (T), and incubation temperature on the development of inter-Sertoli cell (Sc) tight junctions were investigated in vitro by using repetitive measurements of transepithelial electrical resistance (TER). Control cultures developed stable TER of 100-145 omega cm2 during the initial 3-4 days of incubation at either 33 or 36.5 C, suggesting the formation of simple but continuous tight junctions. The presence of FSH (200 ng/ml) at 33 C delayed the onset of TER development by 3-5 days. The addition of FSH at the time of stable TER (day 5) resulted in a rapid (24 h) decrease of TER to 35-40 omega cm2, which returned to the control level during the subsequent 5-7 days. T alone (0.001-10 microM) caused an early and dose-dependent increase in TER to 165-240 omega cm2. In mono-layers incubated at 36.5 C, the continuous presence of FSH resulted in a dose-dependent increase in TER, which stabilized at 260-380 omega cm2 after 4-6 days. At this temperature, the addition of FSH on day 5 caused a rapid drop of TER similar to that observed at 33 C. This drop could not be prevented by antiproteases (aprotinin, epsilon-aminocaproic acid, or 10% fetal bovine serum) and was followed by an increase in TER up to 260-300-omega cm2. The Sc monolayers developed FSH-induced TER of 230-280 omega cm2 at 33 C, but only after several days of culture at 36.5 C. The effects of T at 36.5 and 33 C were similar, but the maximal TER values were significantly higher (290-380 omega cm2) at 36.5 C. The concomitant presence of T and FSH at 36.5 C resulted in the highest TER levels (580-1200 omega cm2) within 4-6 days, suggesting the synergistic effect of the two hormones on TER development. Dihydrotestosterone was more effective than T when used together with FSH, whereas estradiol had no effect. The different patterns of TER did not result from differences in Sc number or metabolic activity and probably reflected developmental and/or maturational changes in the inter-Sc tight junctions. It is concluded that FSH, T, and temperature play a role in the development of high TER by Sc monolayers (formation of tight junctions) in vitro. FSH and T appear to regulate TER via separate pathways and to cooperate by a yet unknown synergistic mechanism.(ABSTRACT TRUNCATED AT 400 WORDS)

Regulation of interleukin-2 and interferon-gamma gene expression in renal failure

Regulated expression of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) genes, induced in cultured peripheral blood mononuclear cells from patients with end-stage renal disease on hemodialysis (HD; N = 13) or peritoneal dialysis (PD; N = 13), was compared to that of 32 normal donors. Culture conditions were chosen that measure the transient, phytohemagglutinin-induced expression of IL-2 and IFN-gamma messenger RNA (mRNA), as well the intactness of post-transcriptional and suppressor T cell-dependent mechanisms that control this expression. The latter was achieved by analyzing the superinduction of IL-2 and IFN-gamma mRNA occurring upon culture with cycloheximide or after low-dose gamma-irradiation, respectively. HD subjects showed a complete loss of inducibility of the IL-2 gene, concomitant with decreased inducibility of IFN-gamma mRNA. In PD subjects, by contrast, expression of IL-2 mRNA was as vigorous as in normal donors, while IFN-gamma mRNA was even more strongly inducible. This difference in gene inducibility is caused by a lack of T cell function in HD subjects. The defect in IL-2 gene expression in HD subjects, occurring most likely at transcription, may underly their impaired immune function.

Profound primary hypothyroidism

Profound primary hypothyroidism is described, presenting as a pituitary tumor in a 46-year-old male with hyperprolactinemia and hypogonadotropic hypogonadism. Replacement therapy with thyroxine reversed all of the patient's abnormalities.

Kinetics of inhibin secretion in static and superfused Sertoli cell cultures in response to follicle-stimulating hormone

It is generally accepted that inhibin secretion in the testis is regulated by FSH; however, the kinetics of inhibin secretion have not been well defined in vivo and in vitro. We investigated the kinetics of inhibin secretion in response to FSH stimulation in static and superfused Sertoli cell cultures. Sertoli cells from 18-day-old rats were cultured in chemically defined medium for 3 days and were then stimulated for different time periods with FSH (0.1 microgram/ml). In static cultures, media were changed every 2, 4, or 8 h, and the superfusion was carried out at a steady rate of 3 ml/h. Inhibin in the culture media was measured by RIA, using antiserum against synthetic replicate [30Tyr]inhibin alpha-chain-(1-30) and, in some experiments, also by bioassay. The dynamics of inhibin secretion were similar in static and superfused Sertoli cell cultures. A significant increase (p less than 0.01) of inhibin secretion was noted after 5-6 h of FSH exposure. After 8-12 h of continuous FSH presence, the secretion of inhibin reached a maximal level, 5-10-fold higher than basal secretion (no FSH). In the continuous presence of FSH, inhibin secretion remained stable at the high level for up to 54 h. FSH removal caused a delayed (8-h) decrease (p less than 0.01) of inhibin secretion, with return to control basal values after approximately 30 h. When FSH was removed 4 h after its addition, inhibin secretion again increased 5-10-fold between 4 and 12 h, then returned to basal values within 30 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Vectorial secretion of inhibin by immature rat Sertoli cells in vitro: reexamination of previous results

The vectorial secretion of immunoactive and bioactive inhibin by immature rat Sertoli cells (Sc) cultured in a two-compartment system was investigated using various culture supports. When Sc were cultured on Millipore-HA filters (used in all previous studies on vectorial secretion of inhibin), both immuno- and bioactive inhibin were found almost exclusively in the apical compartment, suggesting predominantly apical secretion of the glycoprotein. However, the cell-free Millipore-HA filters completely blocked the passage of Sc-conditioned medium (SCCM) inhibin, even after pretreatment with BSA and SCCM to saturate the protein-binding sites. On the other hand, polycarbonate Nucleopore filters or Millicell-CM membranes, both exhibiting extremely low protein-binding capacity, did not significantly block the passage of SCCM inhibin. When Sc were cultured on Nucleopore filters, the immunoactive inhibin was detected in both culture compartments; the basal compartment/apical compartment (BC/AC) ratio was about 1.5 (range, 1.2-1.9). The maximal effective dose of FSH or (Bu)2cAMP caused a 6- to 9-fold increase in the total (BC plus AC) secretion of immunoactive inhibin, but only a 60% increase in the secretion of bioactive inhibin, as evaluated by RIA and pituitary cell bioassay, respectively. The latter phenomenon was not accompanied by any significant change in the basal/apical distribution of either bioactive nor immunoactive inhibin. The presence of testosterone alone (10(-6) M) did not affect either total immunoactive inhibin secretion or its BC/AC ratio. The effects of the concomitant presence of FSH and testosterone did not differ significantly from those of FSH alone. Similarly to testosterone, the lack of any significant effect was observed for 17 beta-estradiol, dihydrotestosterone, androstenediol, and androstenedione regardless of the presence or absence of FSH. The striking dissimilarity of BC/AC ratios of inhibin noted in cultures maintained on Millipore-HA and Nucleopore filters was not due to differences in permeability barrier or Sc functional polarity. When cultured on either support, Sc monolayers developed comparable permeability barriers, as evaluated by measuring the passage of [3H]inulin and development of electrical resistance. The maximal electrical resistance (130-150 omega cm2) developed after 6-8 days of culture on either support. Also, total transferrin secretion and transferrin BC/AC ratio were similar on both supports, suggesting comparable cell numbers and functional polarities. These findings demonstrate that immature Sc in vitro secrete inhibin bidirectionally (BC/AC ratio, approximately 1.5); the polarity of secretion is unaffected by either FSH or various naturally occurring steroids, including testosterone.(ABSTRACT TRUNCATED AT 400 WORDS)

Action kinetics of inhibin in superfused pituitary cells depend on gonadotropin-releasing hormone treatment

We examined the effects of partly purified inhibin from porcine follicular fluid on FSH and LH release in superfused rat pituitary cell cultures exposed to different GnRH stimuli. Pituitary cells from immature male rats were cultured in chemically defined medium. After 4 days of static culture in the absence of inhibin preparation and GnRH, the cell monolayers were superfused for approximately 10 h at a constant speed (0.15 or 0.25 ml/min) with medium with or without inhibin preparation (1 micrograms/ml). During the superfusion, some cultures were stimulated with GnRH (10 nM) continuously or intermittently (1 min/0.5 h or 6 min/1 h). In the basal condition (no GnRH), inhibin suppressed FSH release after 5 h of exposure (P less than 0.01), whereas LH secretion was not affected. In cultures treated with GnRH pulses (of either frequency), the inhibitory effects on the GnRH-stimulated FSH and LH release were statistically significant (P less than 0.01) after 2 h of exposure, became more pronounced in the next several hours, then remained stable until the end of the experiment. In cultures exposed to GnRH continuously, the suppressing effects of inhibin preparation became significant (P less than 0.01) after 3 h of exposure and were maximal at 4 h (52% and 61% of control values for FSH and LH, respectively). Later, the suppressing effect became less pronounce due to the decreasing rate of gonadotropin secretion in control (no inhibin) cultures exposed continuously to GnRH. The magnitude of FSH and LH suppression after 9 h of exposure to the inhibin preparation was statistically different (P less than 0.05) for different GnRH treatments and was more pronounced with GnRH pulses (24-27% and 54-57% of control values for FSH and LH, respectively) than with cultures exposed to GnRH continuously (77% and 89% of control values for FSH and LH, respectively) or in the absence of GnRH (50% and 92% of control values for FSH and LH, respectively). We conclude that both the kinetics and magnitude of action of the inhibin preparation on FSH and LH release can differ significantly depending on the presence or absence of GnRH as well as on the mode of GnRH stimulation. Of particular importance is the observation that suppressive effects of inhibin preparation decline in cultures that have been desensitized to GnRH after prolonged continuous GnRH exposures. These differences stress the role of GnRH-inhibin interactions in the regulation of gonadotropin secretion and emphasize the importance of the mode of GnRH stimulation in studies concerning inhibin action on pituitary cells in vitro.

Age-dependent Sertoli cell responsiveness to germ cells in vitro

This study investigated the effect of germ cells (greater than 80% mid- and late-pachytene spermatocytes) on the secretion of androgen binding protein (ABP) and transferrin by monolayer cultures of Sertoli cells isolated from rats aged 10, 18 or 26 days. There was an age-dependent increase in secretion of ABP and transferrin. Treatment of the Sertoli cell monolayers with hypotonic buffer to remove residual germ cells reduced this increase significantly. On the other hand, addition of germ cells to hypotonic-treated Sertoli cell monolayers increased both basal and FSH + testosterone-stimulated ABP and transferrin secretion at all three ages, although Sertoli cells from 10-day-old animals showed the greatest response. Moreover, addition of germ cells reduced responsiveness to FSH + testosterone in Sertoli cell monolayers obtained from rats aged 18 or 26 days. In monolayers obtained from 10-day-old rats, the opposite effect was noted in the case of ABP secretion. The stimulatory effect of germ cells on ABP and transferrin secretion was proportional to their number, and was reversed 48 h after the germ cells added previously were removed by hypotonic treatment. Whereas the reversal was complete with cultures of Sertoli cells isolated from 18- and 26-day-old rats, approximately 40% of the stimulatory effect remained after removal of germ cells from cultures from the 10-day-old age group. Adhesion of germ cells to Sertoli cell monolayers was also found to be age-dependent, with the largest proportion of added germ cells adhering to Sertoli cells isolated at 18 and 26 days of age. It is concluded that germ cells can significantly and differentially modulate the basal and hormone-stimulated secretory activity of Sertoli cells in vitro and that Sertoli cell responsiveness to germ cells (pachytene spermatocytes) is age-dependent and seems to appear early during the maturation process, before these germ cells appear in the testis.

Sertoli cells in culture: views from the perspectives of an in vivoist and an in vitroist

Culturing Sertoli cells has proven to be a valuable technique to study the responses of these cells under a variety of conditions. This minireview focuses on the culture system and how it has contributed to our knowledge of the capabilities of isolated Sertoli cells. In addition, it focuses on the limitations of the system and the gaps in our knowledge about Sertoli cells in culture and what the results of in vitro studies mean in the intact animal. Caution is urged in interpreting in vitro results to the intact animal without their validation in vivo.

Similar effects of inhibin and cycloheximide on gonadotropin release in superfused pituitary cell cultures

The actions of two inhibin preparations and cycloheximide on gonadotropin release were investigated in superfused pituitary cell cultures. Pituitary cells isolated from 18-day-old male rats were grown in Matrigel-coated superfusion chambers in chemically defined medium. After stationary culture for 4 days, the cell monolayers were superfused at a constant speed (0.25 ml/min) and were intermittently stimulated (6 min/h) with 10 nM gonadotropin-releasing hormone (GnRH). Groups of cultures were exposed to the test substances for varying time periods during stationary culture and/or during superfusion. Inhibitory effects of both inhibin preparations on the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in response to GnRH pulses were observed after 2 h of exposure and became maximal after about 6 h. Basal secretion of FSH between GnRH pulses was also suppressed, whereas the basal interpulse secretion of LH was not changed. When exposure to inhibin was discontinued, the secretion of both FSH and LH progressively increased and returned to control values by approximately 6 h. Cycloheximide (500 ng/ml) affected gonadotropin release with dynamics similar to those observed for the inhibin preparation. These data support the hypothesis that inhibition of gonadotropin synthesis may be an important step in the molecular mechanism of action by which inhibin regulates gonadotropin release.

Influence of germ cells on Sertoli cell secretory activity in direct and indirect co-culture with Sertoli cells from rats of different ages

We examined the effect of direct and indirect Sertoli-germ cell co-culture on androgen binding protein (ABP) and transferrin (TRF) secretion by Sertoli cells (Sc) from 10-, 18-, and 26-day-old rats. Addition of germ cells (Gc), mainly (greater than 80%) pachytene spermatocytes, directly to Sc monolayers enhanced basal and follicle-stimulating hormone (FSH) + testosterone-stimulated ABP and TRF secretion at all three ages. When the Gc were co-cultured indirectly with Sc (separated by a Nucleopore filter), only 50% of the direct stimulatory effect was found at 18- and 26-day-old groups, whereas no difference between direct and indirect co-culture was noted with Sc from 10-day-old rats. With 18- and 26-day-old rat Sc, the Gc effect on ABP and TRF secretion declined after 6 days of Sc culture, reaching the level of Sc-only cultures after 10 days, whereas the direct effect was maintained throughout the entire culture period. With Sc from 10-day-old animals, both direct and indirect effect of Gc decreased after 6 days but the levels of ABP and TRF secretion remained above those of Sc-only cultures. The viability and number of Gc in indirect co-cultures were maintained significantly higher than in Gc-only control cultures. The direct and indirect Gc effect was completely reversed 48 h after the Gc were removed from Sc cultures of 18- and 26-day-old rats, whereas in Sc cultures from 10-day-old rats 40% of the stimulatory effect remained after 48 h of Gc removal. We conclude that Gc can influence Sc secretory activity through both direct contact and some released factor(s). These two pathways may have different relevance at different ages during sexual maturation.

Polyamine profiles in rat testis, germ cells and Sertoli cells during testicular maturation

Polyamine cellular concentrations (putrescine, spermidine and spermine) in the rat testis and testicular cell types were determined by fluorescence spectroscopy of their dansyl derivatives. A method is described to separate dansylated polyamines by high performance liquid chromatography in less than 12 minutes. In rat Sertoli cells, polyamine concentrations (per mg DNA) were greater than those in germ cells and the testis. The concentrations of all three polyamines increased with age. Concentrations of spermidine and spermine in germ cells also increased with age and leveled off after 27 to 35 days. On the other hand, higher putrescine levels were found in the testis of young rats (13 to 22 days) while the greatest spermidine and spermine contents were observed in the testis from rats of 31 to 35 days old. Of great interest, Sertoli cells from all age groups studied released a relatively large quantity of putrescine and a smaller amount of spermidine, but no spermine, into culture media. The amount of polyamine released by Sertoli cells varied with the age of the animal. Sertoli cells from 27-day-old rats released the greatest quantity of putrescine on a per mg DNA basis. The release of putrescine increased after hypotonic treatment that removed contaminating germ cells from the remaining Sertoli cells. It is concluded that cellular polyamine levels in the rat testis, germ cells and cultured Sertoli cells and the amount of polyamines released by Sertoli cells were age-dependent during the first wave of spermatogenesis.

Transferrin secretion in response to different modes of FSH stimulation and cycloheximide in superfused Sertoli cell cultures

The influence of different modes of FSH stimulation and cycloheximide on transferrin secretion by rat Sertoli cells was investigated using a superfusion culture system. Sertoli cells from 18-day-old rats were cultured in serum-free medium on Matrigel-covered slides first in static conditions for 19 hours, and then superfused at a flow rate of 2.5 ml/hour. After an equilibration period of 48 hours to establish the basal rate of transferrin secretion, the cultures were exposed to various modes of FSH stimulation. Sertoli cells stimulated intermittently (20 min/2 hours) up to 22 hours responded to each consecutive FSH pulse with a rapid increase of transferrin secretion followed by a decline toward basal values. Continuous 22-hour exposure to FSH elicited an immediate increase followed by irregular fluctuations and a transient decline towards the baseline. With either mode of FSH stimulation, there was a secondary prolonged increase in transferrin secretion. Although cultures stimulated intermittently or continuously during the entire experimental period (22 hours) secreted similar cumulative amounts of transferrin (10.8 +/- 0.5 micrograms and 11.1 +/- 0.8 micrograms, respectively), there was a direct correlation between the secreted amount of transferrin and the duration of FSH exposure up to 8 hours. Addition of cycloheximide decreased both basal and FSH-stimulated transferrin secretion. However, even when cycloheximide was added 1 hour before FSH, an early secretory peak in response to FSH was still observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental pitfalls in evaluating vectorial protein secretion in vitro; Sertoli cell secretion of androgen-binding protein and transferrin in two-compartment culture chambers

We examined the influence of various Millipore filter pretreatments on the amounts of androgen-binding protein (ABP) and transferrin (Trf) found in the outer (OC) and inner (IC) compartment of two-compartment Sertoli cell (Sc) cultures. When Sc were cultured on untreated Millipore filters, less than 10% of ABP was found in OC during 3 initial culture days compared to similar cultures on pretreated filters. Most of the glycoprotein was shown to be bound by the filter. Pretreatment of Millipore filters with 5% bovine serum albumin (BSA) or 2% fetal bovine serum (FBS) maximally saturated the nonspecific protein-binding sites resulting in OC:IC ratio of ABP similar to that found in cultures on polycarbonate membranes, which exhibit very low protein-binding capacity. In contrast to ABP, about 40% of Trf was bound by the Millipore filter on Day 1, with only trace amounts bound thereafter. These differences were due to much higher secretion rate of Trf than ABP, resulting in a relatively smaller fraction of Trf bound to the filter. Again, the nonspecific binding of Trf was greatly reduced by filter pretreatment with 5% BSA or 2% FBS. It is concluded that complete saturation of protein-binding sites of cellulose ester supports is necessary for reliable evaluation of vectorial protein secretion by Sc and other polarized epithelial cells maintained in this type of culture. The implications of partial saturation of protein-binding sites of culture support in interpreting experimental results are discussed.

Effect of germ cells on vectorial secretion of androgen binding protein and transferrin by immature rat Sertoli cells in vitro

The influence of germ cells (greater than 85% pachytene spermatocytes) on vectorial secretion of androgen binding protein (ABP) and transferrin by immature rat Sertoli cells was investigated using two-compartment culture chambers. The ratio of ABP secreted into the outer and inner compartment in control cultures of Sertoli cells alone was 1.9, and was not influenced by either FSH or testosterone. Co-culture of Sertoli cells in direct contact with germ cells in the presence of FSH decreased this ratio, the decrease being most pronounced (0.7) after 2 days of co-culture. This effect was not observed if the germ cells were not in direct contact with Sertoli cell monolayers. The outer to inner compartment ratio of transferrin in Sertoli cell-alone cultures was 1.6 and, in contrast to ABP, was not significantly influenced by the addition of germ cells, even in the presence of FSH. It is concluded that in immature rat Sertoli cells the polarity of ABP secretion, but not that of transferrin, may be regulated by pachytene spermatocytes (and possibly other germ cells), and that this process is FSH-dependent.

Hyperprolactinemia with prolonged amenorrhea reversed with bromocriptine in a menopausal woman

Bromocriptine treatment of the amenorrhea-galactorrhea syndrome with elevated prolactin levels is well recognized. The return of menses after 30 years in a menopausal woman with this syndrome is described. Lowering of both prolactin and follicle-stimulating hormone levels was found to occur after bromocriptine therapy.

Inhibition of ornithine decarboxylase activity by follicle stimulating hormone in primary culture of rat Sertoli cells

The effect of follicle stimulating hormone on the activity of ornithine decarboxylase (ODC) was determined in primary culture of rat Sertoli cells. Three different FSH preparations (NIH oFSH-S-15, S-16, and eFSH) inhibited ODC activity in rat Sertoli cells under different media conditions. The inhibition was both time- and dose-dependent. The mechanism of the FSH inhibitory effect was studied using dibutyryl cyclic adenosine monophosphate (dbcAMP), 1-methyl-3-isobutylxanthine (MIX), forskolin, and isoproterenol. All of these agents, known to elevate cellular cAMP levels, inhibited ODC activity in cultured rat Sertoli cells. The combined effect of each of these substances plus FSH was either greater than, or equal to, that of FSH alone, and was not additive. Dibutyryl cyclic guanosine monophosphate had no effect on the ODC activity. These findings suggest that FSH inhibition of ODC activity in the rat Sertoli cell may be mediated by cAMP.

Vectorial secretion of transferrin and androgen binding protein in Sertoli cell cultures: effect of extracellular matrix, peritubular myoid cells and medium composition

We examined the effect of various culture conditions on the polarized secretion of androgen binding protein (ABP) and transferrin (Trf) by Sertoli cells (Sc) in vitro. Sc from 18-day-old rats were cultured as confluent monolayers on permeable membranes in two-compartment chambers for up to 11 days. Coating of the membranes with extracellular matrix (ECM) components: collagen IV + laminin (CL) or reconstituted basement membrane (RBM) enhanced ABP and Trf secretion (200% and 150%, respectively), with RBM being more effective than CL in stimulating ABP but not Trf secretion. Neither CL nor RBM significantly influenced the relative amounts of ABP and Trf secreted into the outer (OC) and inner (IC) compartments of the culture chamber (OC/IC ratio). All of these effects were not significantly influenced by the presence of testosterone and serum. Co-culture of Sc with peritubular myoid cells (Pc) significantly increased the secretion of both ABP and Trf, although the magnitude of stimulation and the time-response patterns were different for each protein. Co-culture with Pc also dramatically increased the OC/IC ratios for ABP and Trf. Testosterone (10(-6) M) enhanced the Pc effects. In cultures of Sc alone, presence of 2% fetal bovine serum increased the OC/IC ratios, whereas testosterone had no effect. Based on these results, we suggest a possible role of Pc in the regulation of Sc polarized secretions.

Study of the dynamics of Sertoli cell secretions in a new superfusion, two-compartment culture system

A new superfusion, two-compartment culture system recently developed in our laboratory was used to investigate the dynamic changes in bidirectional secretion of transferrin (Trf) and androgen binding protein (ABP) by rat Sertoli cells (Sc) cultured for up to 12 d under various experimental conditions. The system is unique in that the cells are grown on porous substrate and can be superfused independently at the apical (A) and basal (B) surfaces. The Sc formed confluent monolayers with tight junctions and were highly polarized, morphologically resembling their normal appearance in vivo. The bidirectional secretion patterns (total amount and A:B ratio) of both Trf and ABP were affected by the addition of hormones (testosterone, 10(-6) M; follicle stimulating hormone, 0.1 microgram/ml; and fetal bovine serum 2%), but not by changes in the medium flow rate (0.8 to 3.2 ml/h). The superfusion, two-compartment culture system provides a very useful model for culture of polarized cell monolayers and for the study of bidirectional secretions under more "physiologic" conditions than those provided by static cultures.

Identification of a new Sertoli cell metabolite of testosterone: 5 alpha-androstane-3 alpha,16 alpha,17 beta-triol, by HPLC and GC-MS

Testosterone metabolism by isolated rat Sertoli cells cultured in vitro was investigated using HPLC and GC-MS techniques. Monolayer cultures of Sertoli cells (greater than 90% pure and free of Leydig cells) were incubated for 3-day periods with a stable labeled [2,2,4,6,6-d5]testosterone prepared and used in a 1:1 proportion with unlabeled testosterone as the substrate (5 X 10(-7)M). After incubation, the metabolites were extracted from the media and reacted with oestradiol-antibodies. The antibody-bound components were separated on reverse phase HPLC and the fraction corresponding to oestradiol was analyzed by GC-MS in the form of TMS-ether. One of the metabolites whose mass spectrum contained d0 + d5 species was detected and interpreted to be a triol with a mol. wt of 308. Mass spectra data indicated that this testosterone metabolite is one of the sixteen possible isomers of 3,16,17-trihydroxy androstane. This substance was identified based on the Vm value (27.81) closely resembling that of 5 alpha-androstane-3 alpha,16 alpha,17 beta-triol TMS-ether (Vm reported = 27.78) [1] and when compared directly with synthesized compounds [2-3]. Recently we have demonstrated that similar Sertoli cell preparations contain two 16 alpha-hydroxylases by their ability to convert oestradiol to oestriol [4] and 5 alpha-androstane-3 alpha,17 beta-diol to 5 alpha-androstane-3 alpha,16 alpha,17 beta-triol [3], where the former conversion is not affected by FSH, the latter is significantly stimulated by the presence of FSH. Presence of this new product represents the first example of testosterone conversion to 5 alpha-androstane-3 alpha,16 alpha,17 beta-triol and confirms our previous observation that 16 alpha-hydroxylation of 5 alpha-reduced androgens can occur in the rat testis.

Bipolar secretion of androgen-binding protein and transferrin by Sertoli cells cultured in a two-compartment culture chamber

The influence of various medium supplements on Sertoli cell (Sc) monolayer permeability to [3H]inulin and polarized secretion of transferrin (Trf) and androgen-binding protein (ABP) was investigated in a two-compartment culture chamber. Sc from 14- and 18-day-old rats were maintained for 13 days in one of the following media: Modified Eagle's Medium-Ham's F-12 (DFM), DFM plus insulin, epidermal growth factor, progesterone, hydrocortisone, and vitamins A and E (6F), 6F plus testosterone (7F), 7F plus FSH (8F), 6F plus 2% fetal bovine serum (6F2S), 6F plus 5% fetal bovine serum (6F5S). The monolayer permeability to [3H]inulin decreased rapidly during the initial 3-5 days of culture for the Sc isolated from 18- and 14-day old animals, then remained stable in all media except DFM. Morphological examination revealed the presence of tight junctions between neighbouring Sc in both age groups, indicating their de novo formation. Secretion of Trf was lowest in DFM and steadily declined. In all other media, Trf secretion peaked on day 5 and remained relatively constant after day 7. Medium 7F only slightly and inconsistently increased the secretion, whereas 8F was always highly stimulatory compared to 6F. Supplementation of 6F with serum resulted in the greatest Trf secretion. In the case of ABP, three different secretion patterns were noted depending on the medium composition; secretion was greatest in the presence of 5% fetal bovine serum. The medium supplements also differentially affected the polarity of Trf and ABP secretion. The ratio of Trf secreted to the outer and inner compartments (OC/IC) was approximately 2.0 in DFM and was not influenced by supplements in 6F, 7F, and 8F. However, in serum-containing media, the OC/IC ratio gradually increased with time to about 5.0 on day 13. The average OC/IC ratio of ABP was 1.7 in DFM and, in contrast to Trf, declined to 0.7 in other serum-free media. Serum supplementation reversed and increased the ABP ratio to about 6.0 on day 13. These data indicate that Sc grown on permeable supports form confluent monolayers that limit the diffusion of macromolecules, most likely due to the formation of tight junctions. The monolayer permeability as well as the total and polarized secretion of Trf and ABP are differentially regulated by hormones and serum factors.

Effect of hypotonic treatment on Sertoli cell purity and function in culture

Commonly used enzymic methods for the isolation of rat Sertoli cells yield populations containing approximately 15% germ cells. Although the germ cells become eliminated after several media changes, they could interfere with the use of Sertoli cells for critical studies during the first several days of culture. A brief treatment of Sertoli cell monolayer cultures with 20 mM Tris-HCl (pH 7.4) was found to eliminate most of the residual contaminating germ cells. The duration of this treatment varied from 1.0 to 10 min, depending on cell density in the culture, the degree of germ cell contamination, and the age of animals used for Sertoli cell isolation. In a study of 95% pure, 7-d Sertoli cell cultures, the hypotonic treatment did not alter the DNA or RNA content per dish or the incorporation of [3H]uridine into total and poly A+ RNA. Also, the hypotonic treatment did not alter specific Sertoli cell functions, i. e., secretion of Sertoli cell factor (inhibin) and stimulation of cAMP levels by follicle stimulating hormone in 2-d cultures. Androgen receptor concentration per dish was also not changed. Changes in several general metabolic parameters observed after hypotonic treatment of 2-d cultures were attributed primarily to loss of contaminating germ cells. Consequently, hypotonic treatment can be used to eliminate contaminating germ cells from the Sertoli cell cultures without apparent detrimental effects on a number of Sertoli cell biochemical parameters. This may be of considerable importance when the purity of Sertoli cells is critical for the interpretation of experimental data.

The effect of castration and androgen replacement on rat pituitary follicle stimulating hormone investigated by reversed-phase high performance liquid chromatography

Rat follicle stimulating hormone (rFSH) was analysed in extracts of rat anterior pituitary using a newly developed separation method of reversed-phase high performance liquid chromatography (RP-HPLC) and post-column detection of immunoreactivity (rFSH-IR) by radioimmunoassay (RIA) or immunoprecipitation with a specific anti-rFSH antibody. Good separation of rFSH was achieved on a Waters Radial-Peak 8MBC18 cartridge with a linear (60 min) gradient from 10-60% acetonitrile at constant 0.1% trifluoroacetic acid concentration. The elution profiles of radioiodinated purified rFSH [(125I)rFSH] as well as extracts of adult male and female rat pituitaries contained two main immunoreactive components (peaks 1 and 2) which eluted at 16-17 min and 21 min respectively. In the (125I)rFSH elution profile, the peaks of immunobinding corresponded to two major peaks of radioactivity. The male pituitary showed greater binding to anti-rFSH-serum of peak 1 and 2 eluate compared to female pituitary. At day 20 after orchidectomy, the amount of immunoreactive rFSH (rFSH-IR) increased in both peaks (by 30% in peak 1 and 180% in peak 2); however, the rFSH-IR level in peak 2 appeared to be more variable compared with that in peak 1. Subcutaneous implantation of 5 mg or 15 mg of dihydrotestosterone (DHT) at the time of orchidectomy prevented the post-castration elevation of rFSH-IR at 10 and 20 days after surgery. The precise nature and physiological significance of the two elution peaks are not clear at this time; however, only peak 2 showed immunoreactivity with anti-rLH-alpha-subunit antibody (AFP 87713681) and the elution time of peak 2 coincided with that of (125I) rLH-alpha subunit (AFP-7264 B).(ABSTRACT TRUNCATED AT 250 WORDS)

Maturational and hormonal influences on Sertoli cell function

The maturation of Sertoli cell function was studied by observing properties of cells obtained from 15-, 25-, and 35-day-old rats after 3 days in culture gamma-Glutamyl transpeptidase activity, expressed per mg DNA or per mg protein, and total and soluble protein to DNA ratios increased with age. In contrast, lactate dehydrogenase activity was unchanged between 15 and 35 days of age. Secreted protein to DNA ratios and the secretion of lactate, androgen-binding protein (ABP), and transferrin per mg DNA also increased with age. Two-dimensional electrophoresis maps of [35S]methionine-labeled secretory proteins indicated the appearance of two specific bands [mol wt, 66,000; pI 6.0-6.8 (band 1); mol wt, 56,000; pI 5.3-6.0 (band 2)] between 15 and 35 days of age. The hormone dependence of these parameters was studied in Sertoli cells isolated from rats hypophysectomized at 20 days of age and subsequently treated with oil, testosterone propionate, or testosterone propionate plus FSH for 15-21 days. Hypophysectomy decreased total, soluble, and secreted protein to DNA ratios; hormone treatment in vivo increased these ratios compared to oil treatment. gamma-Glutamyl transpeptidase activity was significantly decreased by hypophysectomy and increased, compared to oil treatment, by hormone treatment. In contrast, lactate dehydrogenase activity per mg DNA was also decreased by hypophysectomy, but was unaffected by hormone treatment. [35S]Methionine incorporation into secreted protein and secretion of ABP and lactate per mg DNA were all decreased by hypophysectomy, whereas transferrin secretion per mg DNA was unaffected. While the hormone treatments increased ABP secretion, they had no effect on lactate or transferrin secretion, expressed per mg DNA. The [35S]methionine-labeled secretory proteins (bands 1 and 2) were not visible in two-dimensional electrophoresis maps after hypophysectomy of the donor animals. Treatment with testosterone propionate or testosterone propionate plus FSH in vivo resulted in the appearance of the acidic components of band 2. These data demonstrate that changes reflecting in vivo maturational patterns and hormonal influences on Sertoli cell function persist, at least in a relative sense, after 3 days in culture. Although the majority of [35S]methionine-labeled Sertoli cell cellular and secretory proteins were present under all conditions, maturation- and hormone-dependent changes in a number of specific functions were demonstrated.

Polarized Sertoli cell functions in a new two-compartment culture system

Sertoli cells in vivo are highly polarized and interact with the inner (tubular) and outer (interstitial) fluids. To simulate this condition in vitro we developed a two-compartment culture system in which confluent Sertoli cell monolayers were grown on permeable supports (Millipore filters) separating the inner and outer fluid compartments. Monolayer permeability to (3H)-inulin decreased by 90% after 5 to 7 days of culture, presumably due to formation of tight junctions. This process was influenced by cell plating density. The cells were highly polarized morphologically, resembling their appearance in vivo, and secreted transferrin bidirectionally into both fluid compartments. The amount of transferrin secreted was 166% to 250% of that secreted by the same number of Sertoli cells cultured in plastic dishes. Testosterone (5 X 10(-8) M) doubled and testosterone + FSH (0.1 microgram/ml) increased transferrin secretion 3.6-fold. These results demonstrate that under suitable culture conditions the Sertoli cells remain both morphologically and functionally polarized, reflecting a more physiologic state.

Specific irritability of acupuncture points as an early symptom of multiple sclerosis

28 patients suffering from multiple sclerosis were treated by acupuncture. The age of the patients ranged from 24 to 60 yr. Results of the treatment were satisfactory, but remarkable spontaneous remissions, characteristic for this illness, make any treatment difficult to evaluate. In this article the peculiar behaviour of all treated patients is described: increased sensibility of the skin over the acupuncture loci, while insertion of the acupuncture needles provoke spasms, clonus and even tonic-clonic contractions of the muscles of the extremities. This phenomenon is very specific and can be used as an early sign of this ill-fated illness.

Localization of ornithine decarboxylase in rat testicular cells and epididymal spermatozoa

We have employed a monospecific, polyclonal antibody to ornithine decarboxylase (ODC) for the immunocytochemical localization of ODC in freshly isolated testicular cells, epididymal spermatozoa, and cultured Sertoli cells. Antigenically detectable material was present in the cytoplasm of all cell types tested and was highly concentrated in the acrosomal vesicle of round spermatids and in the acrosome region of epididymal spermatozoa. The specific enzymatic activity of ODC, as measured biochemically, was much higher in the interstitial cells than in the other testicular cell types, and no ODC activity was detected in the epididymal spermatozoa or in the Sertoli cells after 5 days in culture. These studies showed that, while all testicular cell types studied contained ODC-like immunoreactive molecules, only testicular germ cells and interstitial cells exhibited detectable ODC activity.

Leishmania tropica: protective response in C3H mice vaccinated with excreted factor crosslinked with the synthetic adjuvant, muramyl dipeptide

Excreted factor, an immunosuppressive, acidic polysaccharide released by promastigotes of Leishmania tropica major in culture, was chemically crosslinked to the synthetic adjuvant muramyl dipeptide via the bifunctional imidoester dimethyladipimidate and poly-L-lysine. This conjugate, an uncrosslinked mixture of the components, or each of the components alone were injected one to three times into different groups of 8- to 12-week-old C3H mice. The mice were challenged 2 weeks after the last injection with 2 X 10(6) promastigotes of L. t. major in the base of the tail. For the next 5 weeks, the animals were monitored for number of parasites and size of the lesion which developed at the site of the challenge. Mice receiving one intraperitoneal injection of the conjugate were partially protected against challenge. Treated animals had higher initial parasite numbers but showed a more rapid clearing of the parasites. Furthermore, the treated animals developed smaller lesions that healed quicker than did those of the control groups. Multiple injections, or injection into a footpad, rather than intraperitoneally, reduced the ability to elicit a protective response. On the other hand, muramyl dipeptide injected into a footpad was partially protective. Antibody production to excreted factor, which was measured by indirect hemagglutination of sensitized erythrocytes, was detected after challenge in mice which had received conjugate or conjugate components. A delayed hypersensitivity reaction (measured by skin testing) was not detected in any of the groups prior to challenge.

Testicular peptides and their endocrine and paracrine functions

A number of testicular peptides appear to have endocrine and/or paracrine functions. Most, if not all, of these peptides are secreted by the Sertoli cells into the tubular fluid. Although their physiological role has not been fully clarified, these secretory products are believed to play an important role in the local regulation of testicular functions, particularly the spermatogenic process. Presence of high affinity, specific binding sites for transferrin and androgen binding protein, both secreted by the Sertoli cells, has been demonstrated on the round spermatids and/or pachytene spermatocytes. Since within the seminiferous tubules, only the Sertoli cells respond directly to follicle stimulating hormone and testosterone, they could mediate the hormonal effects on spermatogenesis by providing certain products which may be essential during specific stages of germ cell differentiation.

Pituitary binding of 3H-labeled Sertoli cell factor in vitro: a potential radioreceptor assay for inhibin

We have previously demonstrated that binding of partially purified, 3H-labeled Sertoli cell factor (SCF) to rat anterior pituitary homogenates was tissue specific, saturable, time and temperature dependent, and competitively inhibited by unlabeled SCF. The present study further characterized the binding of [3H]SCF to rat anterior pituitary in vitro and explored its potential use as a radioreceptor assay for SCF and other inhibin preparations. [3H]SCF was synthesized by rat Sertoli cells cultured in the presence of [3H]leucine (5 mu Ci/ml) and was then partially purified by Sephadex gel filtration and high pressure liquid chromatography. The purified [3H]SCF had a specific activity of approximately 20,000 dpm/micrograms protein and was biologically active in pituitary cell cultures. The binding was carried out in 0.5 ml buffer, containing one pituitary equivalent and, wherever appropriate, various unlabeled competing substances. The binding was optimal at pH 7.4 and was decreased by pretreatment of [3H]SCF with trypsin (0.25%; 37 C; 30 min) or heat (100 C; 10 min). Storage of the pituitary glands at -20 C for several months and differences in animal age did not affect total binding per pituitary, but the amount of radioactivity bound per mg pituitary tissue declined progressively between 18-90 days of age. Over 90% of the bound [3H]SCF was competitively inhibited by excess unlabeled SCF and several other inhibin preparations of testicular origin: high mol wt fraction of ram testis fluid (mol wt, greater than 10,000), low mol wt fraction of ram testis fluid (mol wt, less than 5,000), ovine testicular lymph, and aqueous rat testicular extract. The degree of inhibition was dose dependent, and except for the low mol wt fraction of ram testis fluid, the displacement curves were parallel (slope, 0.95). In contrast, various noninhibin substances tested [rat androgen-binding protein, bovine LH, BSA, native GnRH, or GnRH agonist analogs D-Ser-(tBu)6-des-Gly10-GnRH-N-EA and D-Ala6-des-Gly10-GnRH-N-EA] did not significantly compete for the [3H]SCF binding. The binding ability correlated well with inhibin biological activity in vitro. These results provide additional evidence for the presence of SCF-binding sites in the rat anterior pituitary which interact with several different inhibin preparations of testicular origin but appear to be distinct from GnRH-binding sites. Our results also indicate that the pituitary binding may be used as a rapid radioreceptor assay for SCF and various other inhibin preparations.

Control of androgen cytosol receptor concentrations in Sertoli cells: effect of androgens

Androgen receptor concentrations were measured in Sertoli cells under a variety of conditions. After brief (30- to 60-min) incubation of cultured cells with [3H]R1881 (methyltrienolone), cytosol receptor concentrations were greatly diminished, and nuclear bound steroid was elevated. Removal of the exogenous steroid was accompanied by a return of cytosol receptor to preincubation concentrations by 1 h and a slower decline in nuclear bound steroid. In the continued presence of R1881 or testosterone, cytoplasmic receptor concentrations declined and then returned to or above preincubation concentrations by 6-17 h. Actinomycin-D and cycloheximide did not alter this pattern. Over this same interval, nuclear bound steroid concentrations remained elevated. Exposure of the cells to R1881 or testosterone for the entire 72-h culture period did not alter cytoplasmic receptor concentrations. Cytoplasmic androgen receptor concentrations were decreased in Sertoli cells from hypophysectomized rats 15-22 days after surgery compared to those in cells from intact controls. Treatment with testosterone propionate (0.5 mg/day) or FSH (75 micrograms/day) prevented the decline in receptor concentrations. Cryptorchidy (33 days) also decreased cytosol receptor concentrations. These data indicate that exposure to androgens can influence Sertoli cell cytosol androgen receptor concentrations in vitro and in vivo. The Sertoli cell adapts to the continual presence of androgens with a return of cytosol receptor while maintaining elevated concentrations of nuclear bound steroid. In vivo, androgen treatment can maintain cytoplasmic receptor concentrations in the absence of pituitary hormones in the immature rat.

Follicle stimulating hormone binding inhibiting activity and inhibin properties of human ovarian cystic and porcine follicular fluid

Ovarian cystic fluid was obtained from 13 regularly cycling women with the operative diagnosis of ovarian serous (n = 6), mucinous cystadenomas (n = 3) and simple follicular cysts (n = 4). The effects of the fluids, after steroid extraction with charcoal treatment, on the binding of follicle stimulating hormone (FSH) to rat testicular homogenates and on the in vitro secretion of FSH and luteinizing hormone (LH) by rat pituitary cell preparations were studied. Similar studies were conducted simultaneously with steroid-free porcine follicular fluid (pFF). Human ovarian cystic fluids produced a marked inhibition of FSH-binding activity in the absence of an effect on FSH or LH secretion. In contrast, pFF exhibited both FSH-binding inhibitory (FSH-BI) and inhibin activities. Furthermore, heating did not alter the FSH-BI activity nor the inhibin properties of steroid-free human ovarian cystic fluids nor porcine follicular fluid.

Transient neurological deficits secondary to saccular vertebrobasilar aneurysms. Report of two cases

Aneurysms have rarely been implicated as a possible cause of transient neurological deficits, and most reports of this phenomenon describe aneurysms in the anterior circulation. There is only one previous report of a saccular posterior circulation aneurysm associated with transient ischemic attacks. The authors document two cases of giant saccular vertebrobasilar artery aneurysms associated with transient neurological deficits.