Safety and Therapeutic Profile of a GnRH-Based Vaccine Candidate Directed to Prostate Cancer. A 10-Year Follow-Up of Patients Vaccinated With Heberprovac

Heberprovac is a GnRH based vaccine candidate containing 2.4 mg of the GnRHm1-TT peptide as the main active principle; 245 μg of the very small size proteoliposomes adjuvant (VSSP); and 350 μL of Montanide ISA 51 VG oil adjuvant. The aim of this study was to assess the safety and tolerance of the Heberprovac in advanced prostate cancer patients as well as its capacity to induce anti-GnRH antibodies, the subsequent effects on serum levels of testosterone and PSA and the patient overall survival. The study included eight patients with histologically-proven advanced prostate cancer with indication for hormonal therapy, who received seven intramuscular immunizations with Heberprovac within 18 weeks. Anti-GnRH antibody titers, testosterone and PSA levels, as well as clinical parameters were recorded and evaluated. The vaccine was well tolerated. Significant reductions in serum levels of testosterone and PSA were seen after four immunizations. Castrate levels of testosterone were observed in all patients at the end of the immunization schedule, which remained at the lowest level for at least 20 months. In a 10-year follow-up three out of six patients who completed the entire trial survived. In contrast only one out eight patients survived in the same period in a matched randomly selected group receiving standard anti-hormonal treatment. Heberprovac vaccination showed a good security profile, as well as immunological, biochemical and, most importantly, clinical benefit. The vaccinated group displayed survival advantage compared with the reference group that received standard treatment. These results warrant further clinical trials with Heberprovac involving a larger cohort.

Gradual reduction of testosterone using a gonadotropin-releasing hormone vaccination delays castration resistance in a prostate cancer model

In a previous study aimed to design a novel prostate cancer vaccine, the authors of the present study demonstrated the advantage of combining the adjuvants Montanide ISA 51 with very small size proteoliposomes (VSSP) to promote a significant humoral immune response to gonadotropin-releasing hormone (GnRH) in healthy animals. The present study compared the efficacy of this vaccine formulation versus the standard treatment currently available in terms of preventing the development of tumors in DD/S mice injected with Shionogi carcinoma (SC) 115 cells. The results demonstrated that 5 non-vaccinated control mice exhibited a fast tumor growth, and succumbed to the disease within 19-31 days. Mice immunized with the GnRH/Montanide ISA 51/VSSP vaccine exhibited a moderate decline in testosterone levels that was associated with a decrease in anti-GnRH antibody titers, which lead to a sustained tumor growth inhibition. In total, 2 mice in the immunized group exhibited complete remission of the tumor for the duration of the present study. In addition, castrated mice, which were used as a control for standard hormonal therapy, exhibited an accelerated decrease in tumor size. However, tumor relapse was observed between days 50 and 54, and between days 65 and 85, following the injection of SC 155 cells. Therefore, these mice were sacrificed at day 90. The present study concludes that the slow and moderate reduction of testosterone levels observed using the GnRH-based vaccine may delay the appearance of castration resistance in a Shionogi prostate cancer model. These findings suggest that this vaccine may be used to delay castration resistance in patients with prostate cancer.

Estradiol/Androgen Receptors During Aging: Microsomal Distribution In Human Benign Prostatic Hypertrophy

Estradiol and androgen receptor levels were determined in benign prostatic hypertrophy tissue by means of dextran-coated charcoal method. 80% of the cases contained estrogen receptor, whereas 85% of cases contained the androgen receptor. In 50 year old patients, nuclear estradiol and androgen receptors were 48% and 34% higher than the cytosolic values, respectively, whereas in 70 year old patients, the levels of nuclear estradiol and androgen receptors were 6% and 57% higher than the cytosolic values, respectively. Nuclear androgen receptor in 50 year old patients was 34% higher than the estradiol receptor, and in 70 year old patients, androgen receptor was 23% higher than the estradiol receptor. Cytosolic values of estrogen receptor in 50 year old patients were diminished 50%, whereas in 70 year old patients, the ER value was increased 40% with regard to androgen receptor. On the other hand, estradiol receptor values measured in microsomal fractions, and were higher when compared to androgen receptor levels (mean percentage +/- 50%). These findings suggest that the biological effects due to the subcellular distribution of AR or ER and that their microsomal distribution would constitute a reserve mechanism and activation of receptors for the continued growth of benign prostatic hypertrophy.

PROSTATIC CANCER/BENIGN PROSTATIC HYPERTROPHY. SUBCELLULAR DISTRIBUTION OF ESTRADIOL/ANDROGEN RECEPTORS

Six microsomal population of estradiol and androgen receptors have been characterized in human benign prostatic hypertrophy (BPH) and prostate cancer (PCa). Estradiol receptor (ER) and androgen receptors (AR) were extracted using 0.6 M KCL and determined by the dextran-coated charcoal method. ER and AR levels were smaller in BPH plasma membranes (PM) than in Pca cases. For functions 3, 4, 6, the ER values in PCa were 25-38% less with regard to BPH ER values. Whereas in PCa, AR values obtained in all fractions were higher when compared to BPH AR values. In benign prostatic hypertrophy and prostatic cancer, ER and AR levels were significantly higher in the nuclear fraction. In the nuclear fraction, ER and AR levels in BPH and PCa were significantly different. The subcellular distribution of AR and ER in BPH and PCa constitutes a reservation mechanism and processing a receptors for their continued growth.

HUMAN PAPILLOMAVIRUS HPV-16 DNA AS AN EPITHELIOTROPIC VIRUS THAT INDUCES HYPERPROLIFERATION IN SQUAMOUS PENILE TISSUE

The prevalence of human papillomavirus HPV-16DNA sequences in 57 penile carcinoma biopsies was examined using the polymerase chain reaction (PCR) with type specific internal probes, employing HPV consensus primers from the L1 region. The cases comprised 39 typical squamous cell carcinoma and 18 specimens with different subtype. PCR products were analyzed and HPV-16DNA was detected in a high percentage of specimens. Thirty-eight biopsies were HPV-16DNA positive. This determination was correlated with cellular differentiation and growth pattern. Our data corroborates that squamous cell carcinoma was invariably associated with HPV-16DNA.

Gonadotrophin releasing hormone-based vaccine, an effective candidate for prostate cancer and other hormone-sensitive neoplasms

Prostate growth, development, functions, and neoplastic transformation is androgen dependent. Estrogens have similar effects in the ovary and breast. Previous studies using gonadotrophin releasing hormone (GnRH/LHRH) vaccines have shown the usefulness of immunization against this hormone in prostate (PC) and breast cancer (BC). We have synthesized a peptide mutated at position 6 and attached to the 830-844 tetanic toxoid (TT) helper T cell sequence in the same synthesis process. After repeated pig immunizations, we have demonstrated a vaccine that significantly decreased testes size (p < 0.001), prostate (p < 0.01), seminal vesicles (p < 0.01), and testosterone (T) castration [0.05 nM ml(-1) (p < 0. 01)]. Similar results were obtained in adult male and female healthy dogs and Macaca fascicularis models. These data indicate that this GnRHm1-TT vaccine is safe and able to induce significant tumor growth inhibition in the Dunning R3327-H rat androgen responsive prostate tumor model. In these rats, the immunization induced high anti-GnRH titers concomitant with T castration reduction (p < 0.01) in 90% of the animals tested. In addition, 70% of the responders exhibited tumor growth inhibition (p = 0.02) and a survival rate approximately three times longer that those of untreated rats. These data indicate that GnRHm1-TT vaccine may be a potential candidate in the treatment of PC, BC, and other hormone-dependent cancers.

Clinical significance of nuclear matrix-estradiol receptor complex in human sperm

Estrogen receptor levels were determined in nuclear matrix of human spermatozoa of normospermic fertile men and idiopathic infertile men. In noncapacitated sperm cells, the distribution of the estrogen receptor in normospermic fertile men was present in 50% of the cases, whereas in idiopathic infertile men was present in 19% of the cases. In capacitated sperm cells, the distribution of the estrogen receptor in normospermic fertile men was present in 80% of cases, whereas in idiopathic infertile men was present in 31% of the cases. The values of estrogen receptors in capacitated and noncapacitated sperm cells of normospermic fertile men were 91 +/- 21 and 26 +/- 7 fmol/10(8) sperm cells, respectively, whereas in capacitated and noncapacitated sperm cells of idiopathic infertile men, the estrogen receptor values were 50 +/- 17 and 22.5 +/- 9 fmol/10(8) sperm cells, respectively. The diminution of the estrogen receptor levels in the nuclear matrix could be a biochemical indicator of male factor infertility.

Induction of nuclear matrix-estradiol receptor complex during capacitation process in human spermatozoa

Estrogen receptor levels were determined in capacitated and noncapacitated sperm cells of normospermic men by the charcoal dextran method. The estrogen receptor of the nuclear matrix was released using hypertonic solutions. The distribution of the estrogen receptor was higher by 30% in capacitated spermatozoa as related to noncapacitated spermatozoa. The values of estrogen receptors in capacitated and noncapacitated spermatozoa were 91 +/- 21 fmol/10(8) sperm cells and 26 +/- 7 fmol/10(8) sperm cells, respectively. The association of estrogen receptor-nuclear matrix may be an important factor in the regulation of the transcription of the sperm genome of capacitated spermatozoa during the pronuclei stage.

Hormone-related factors associated with hormone receptor levels in breast cancer

Estrogen receptor (ER) and progesterone receptor (PgR) levels were determined in patients with a ductal infiltrating breast carcinoma. In premenopausal patients, the distribution of the PgR was higher than that of the ER. With increasing age of the patients, the concentration of the ER increased, whereas the PgR values showed an inverse relationship. According to the menstrual status, ER and PgR values were found to be higher in postmenopausal patients than in premenopausal ones. In relation to body fat distribution, in premenopausal patients the ER or PgR values were not found to be statistically significantly different (data no shown). In postmenopausal patients, the concentration of ER was diminished by 20% in patients with obesity of the upper body segment and by 40% in patients with obesity of the lower body segment as compared with the ER values of nonobese patients. While the PgR values diminished by 20% in patients with obesity of the lower body segment, in relation to PgR values of patients with obesity of the upper body segment, we found no statistically significant differences when compared with the PgR values of nonobese patients. With regard to the body mass index, this has remained constant in both types of body fat distribution. When body mass index values were compared with serum ER and PgR levels, no statistically significant differences were found.

Measurement of androgen and estrogen receptors in breast tissue from subjects with anabolic steroid-dependent gynecomastia

In order to assess the relationship between anabolic steroid administration and gynecomastia, we studied the effects produced by administering nandrolone decanoate and a mixture of propionate, phenilpropionate, isocaproate and testosterone decanoate to bodybuilders during a six month period. The following significant changes occurred: a 53% reduction in serum testosterone; LH and FSH levels were suppressed to 77% and 87%, respectively, in comparison to control values; and although 45% of the subjects showed an increase in serum estradiol levels, no statistically significant differences were found compared with control estradiol levels. With regard to estradiol and androgen receptors, 85% of gynecomastia tissue contained estradiol or androgen receptors, while 40% contained both. The mean values of estradiol and androgen receptors in the cytosol were 65 +/- 10 and 52 +/- 5 fmol/mg protein, respectively. Nuclear androgen and estradiol receptor levels were 33 +/- 7 and 67.5 +/- 9 fmol/mg protein, respectively. The presence of hormone receptors in gynecomastia receptive cells provides support for the hypothesis that gynecomastia is steroid-dependent.

In vitro cytotoxicity of flavonoids against MK2 and C6 tumour cells

The cytotoxic effect of five flavonoids isolated from the aerial parts of the Asteraceae family of plants were studied in vitro using LLC-MK2 and C6 glial cells. Agehoustin A was shown to be cytotoxic for both cells (71% or 67% cell death). Agehoustin B and artemetin, which lack a methoxy group at C-8 (RI), were not cytotoxic for the cells (19% and 16% cell death). The three flavonoids showed considerable suppressive effects on LLC-MK2 and C6 cell growth. Lucidin-dimethylether and gnaphaliin were also not cytotoxic for cells but they had no suppressive effect on cell growth. The results show a structure-cytostatic activity relationship. We suggest that the methoxy group on C-8 and on the B ring are responsible for death cell.

Endometrial progesterone and estradiol receptors in patients with recurrent early pregnancy loss of unknown etiology--preliminary report

INTRODUCTION

It is not possible to identify the cause of the recurrent early pregnancy loss in approximately half of the cases, and different results have been reported according to estrogen (ER) and progesterone receptors (PR). The objective of this work was to evaluate the PR and ER levels in the endometrium of patients with recurrent early pregnancy loss, and to compare them with those of patients with proven fertility.

MATERIAL AND METHODS

Endometrial receptors (R) for estrogen and progesterone as well as estradiol (E2) and progesterone (P) levels were determined in patients with recurrent early pregnancy loss, and compared with patients with proven fertility.

RESULTS

The E2 and P levels, and the E2/P ratio did not show significant differences among the groups. Estrogen receptor in the cytoplasm and nucleus was lower in those with miscarriages, but without significant differences between the groups. However, the cytoplasmic PR was lower in those with pregnancy loss (p < 0.04), while nuclear PR was lower in the control group (p < 0.04).

CONCLUSION

Maybe low PR levels can be the cause of early pregnancy loss of unknown etiology, but this deserves further investigation.

Defective function of membrane potential (psi) on sperm of infertile men

Membrane potential across the plasma membrane (psi) of human sperm was determined by measuring the accumulation of triphenylmethylphosphonium (TPMP+). Washed sperm of fertile or infertile men were suspended, incubated in low-K+ and high-Na+ or high-K+ and low-Na+ medium, and allowed to take up the cation TPMP+ to a steady state (20 min at 37 degrees C). Under these conditions a psi of -75 +/- 6 mV was observed in sperm cells of fertile men, while in spermatozoa of idiopathic and asthenozoospermic infertile men, the psi was of 35 +/- 5 mV and 32 +/- 5 mV, respectively. Upon depolarization of the sperm membrane by K+, the transport system Na(+)-K+ in spermatozoa of idiopathic infertile men decreased 53 +/- 3.5%, while that in sperm cells asthenozoospermic men decreased 57 +/- 3% with respect to spermatozoa of fertile men. The results of these studies indicate their possible application to the diagnosis of male infertility.

Effect of naloxone on serum testosterone in adult male rabbits

Considerable evidence suggests that endogenous opioids may play an important role in the hypothalamic LH-releasing hormone. Administration of high doses of naloxone, an opiate antagonist, produces an increase in plasma concentration of LH. Naltrexone administration to healthy males produces an increase in both immunoactive and bioactive LH. The objective of the present work was to assess the effect of low doses of naloxone during 10 consecutive days on testosterone serum levels in rabbit. Three groups of five rabbits were injected with naloxone or saline. Naloxone was tested at 0.1 and 0.01 mg/kg day-1. Blood samples were taken at 90 min and 1, 2, 4, 7, 10, and 14 days after starting naloxone administration. Plasma testosterone (T) levels were measured by RIA. T levels increased progressively through the study in the experimental groups. The differences were significant after days 4 and 7 for 0.01-mg/kg and 0.1-mg/kg doses, respectively. T levels in both groups peaked at day 10 and decreased at day 14 (4 days after treatment).

[Receptor (ER, PgR) levels as prognostic factors in the endocrine therapy of pre- and post-menopausal patients with stage III infiltrative ductal and lobular cancer of the breast]

Receptors group (ER+, PgR+) in post-menopausal and pre-menopausal patients with ductal and lobular infiltrating mammary cancer clinical stage III and poorly differentiated histological assessment was studied. Levels of (ER+, PgR+) were correlated to endocrine therapy response (Tamoxifen) after 5 years of its administration. Both pre and post-menopausal patients with infiltrating ductal carcinoma, the (RE+, RPg+) tumour content, the mean values were 52 +/- 8, 53 +/- 11 fmol/mg protein and 111 +/- 20, 36 +/- 7 fmol/mg protein, respectively. With regard to lobular carcinoma, the (RE+, RPg+) tumour content, the mean value was 109 +/- 28, 46 +/- 12 fmol/mg protein in pre-menopausal patients, whereas it was 287 +/- 60, 66 +/- 18 fmol/mg protein in post-menopausal patients. The tumour was considered (ER+, PgR+) when specific binding was than 10 fmol/mg protein. In both ductal and lobular carcinoma the mean (ER+) concentrations are significantly different between the post and pre-menopausal patients, while the mean (PgR+) concentrations are significantly different in post-menopausal women. After five years of treatment with tamoxifen, survival analysis of patients with ductal infiltrating and lobular infiltrating carcinoma revealed a very strong correlation between levels of receptor group (ER+, PgR+) and their response to endocrine therapy.

Estradiol and progesterone endometrial receptors and body fat distribution in obese women

The content of endometrial receptors for estradiol (ER) and progesterone (PR) was determined in three groups (10 women each) classified with respect to body fat distribution: (1) normal, nonobese; (2) lower body segment obesity and (3) upper body segment obesity. The ER in group 3 were significantly (p < 0.05) higher than those of group 1. As regards PR, no statistical differences were found among the three groups. These findings demonstrate different endometrial ER concentrations in obese women according to body fat distribution, greater in upper segment obesity. Probably the lack of progesterone as well as other factors in the endocrine milieu of these patients may determine the differences found; therefore, future research on this matter should be carried out.

[Reductive effect of the sesquiterpenic lactone "Helenalin " and its metallic derivatives in the formation of the estradiol receptor complex in breast tumor tissue]

Chemotherapy for systemic therapy in breast cancer has been widely used, and has been supported by many varied compounds with different origins and different compositions. Nevertheless, all of them produce several side adverse effects which must be taken into account. For this reason we must study new possibilities in which the administered drug acts selectively on the tumour cell without injuring healthy tissue. For studying its effect, a gamma lactone called "Helenaline" and its metalic derivates He-Co, He-Hg and He-Cu were studied, which chemical composition allows them to react with -SH residues present in the tumour cell receptors, which when interspaced by a previous reaction, could modify its structural composition and finally its affinity by the hormone. The inhibition effect for formation of estradiol-receptor complex in breast tumour tissue using Helenaline 12 n M and 126 n M was studied, obtaining 14% and 56% inhibition effect respectively. When He-Co, He-Hg and He-Cu effect was studied, this effect was raised obtaining 11%, 10.5% and 60% with 12 nM and 44.5%, 74.4% and 86% with 126 nM respectively.

Presence and chemical composition of glycoproteic layer on human spermatozoa

Studies from electronic microscopy disclosed the presence of an electrodense stranded and branch-like electrodense layer that extends toward extracellular space. Chemical composition of this glycoproteic layer showed that protein and total sugar content is similar (0.98 microgram/microgram protein). As for the total sugar content of this glycoproteic constituent, sialic acid accounts for 40%, hexosamines 27%, and fucose 30%. Electrophoresis characterization of this constituent showed the presence of 6 different motility bands. Risen levels of sialic acid indicate the contribution of sialic residue in the net charge of the sperm membrane, its role during capacitation, and its possible participation in the formation of binding bridges between sperm membrane and ovum.

[The role of estradiol and progesterone receptors in the selection of endocrine therapy fo patients with fibrocystic mastopathy]

Estradiol and progesterone receptors were analyzed in breast tissue of 100 women with mastopathy fibrocystic. Four groups were found according to the receptors detected: (R-E+, R-Pg+); (R-E+, R-Pg-); (R-E-; R-Pg+); (R-E-, R-Pg-). Ten percent were positive for both receptors, while 75 percent were negative for both estradiol and progesterone receptors. Ten percent were estradiol receptor positive (R-E+). Eight percent were progesterone receptor positive (R-Pg+). In this pathology type were considered "receptor positive" when specific binding was higher than 6 fmol/mg. protein. These "receptor positive" had specific binding in the range of 6.1-80 fmol/mg. protein and was considered "receptor negative" when specific binding was less than 6 fmol/mg. protein. While there was no correlation between the two receptors and patient age. We discuss the presence, type of estradiol and progesterone receptors for the hormonal treatment of patients with mastopathy fibrocystic.

[Cholesterol and phospholipids in human seminal plasma before and after vasectomy]

Before and 2.6 months after vasectomy the alterations of secretory capacity and physiologic damage of the accessory genital glands, were evaluated by means of chemical analyses of certain constituents of seminal plasma such as free cholesterol, esterified cholesterol and phospholipids. The results of these studies showed that the ratio between the concentration of free cholesterol and esterified cholesterol is constant six months after vasectomy and the concentration of phospholipids decreases two months after vasectomy. These results are significant and may be important to know the alterations of secretory capacity of the human genital glands after vasectomy.

Action of cholinergic drugs on accumulation of TPMP+ on human spermatozoa

Neurotransmitters or antagonists with nicotinic- or acetylcholine-type receptors were utilized to measure the accumulation of the radiolabeled lipophilic cation triphenylmethylphosphonium (TPMP+) on the plasma membrane of human sperm. Washed sperm incubated in the presence of TPMP+ in a low-K+ or high-K+ medium were allowed to take up the cation to a steady state (i.e., 20 min at 37 degrees C). The difference between TPMP+ in each incubation medium was inserted in the Nernst equation yielding a resting membrane potential of -69 +/- 2 mV. The addition of nicotine or acetylcholine to the low-K+ and high-K+ medium induced a hyperpolarization of 17% and 20%, respectively. In the presence of propranolol the membrane potential decreased by 44%. The association of nicotinic or acetylcholine receptor on human sperm or adrenergic beta-receptor blocking agent may alter the ionic permeability of the membrane, possibly due to hyperpolarization or depolarization.

[Sialyltransferase activity in the spermatic membrane and its relation to human fertility and sterility]

Sialyltransferase activity was determined on normospermic men sperm cells (greater than 80 x 10(6) sperm/ml and 75% motility) and oligospermic infertile sperm cells (less than 20 x 10(6) sperm/ml and less than 20% motility) and asthenospermic (greater than 40 x 10(6) sperm/ml and less than 10% motility). Sialytransferase activity is quantified by means of the transference of radioactivity of CMP-3H-sialic acid toward the exogenous acceptor (asialofetuin). The enzyme substrate complexes formed in presence of phosphotungstic acid result precipitated insoluble, which was retained on glass fiber filter. The sialyltransferase activity decrease in oligospermic sperm cells 62 +/- 3% and in the asthenospermic decreased 57 +/- 4% with respect normospermic sperm cells. The decrement on sialyltransferase activity in the infertile sperm, permits to assume that this enzyme probably participates as a direct cause of its pathology with detrimental structural and functional integrity of the plasma membrane.

[The role of hyperpolarization and depolarization of the membrane of the human spermatozoon]

The electric potential across the membrane (psi) is evaluated through the accumulation of the lipophilic, radiolabelled, triphenylmethylphosphonium (3H-TPMP+), cation on membrane human sperm. The washed sperm cells, were incubated in presence of 3H-TPMP+ in low-K+ medium or high-K+ and allowed to take up the cation to steady-state (ie; 20 min at 37 degrees C). By using this differential, the value obtained was inserted in the Nernst equation, this value yielded a psi of -69 +/- 2 mV. The presence of divalent cations Zn++ and Mg++ in the incubation medium both induced a hyperpolarization of 10% and 8.6%, respectively. The addition of specific reagents such as p-chloromercuribenzene-sulfonate and ethylene-diamine-tetraacetic acid sodium salt both decreased the psi 35% and 58% respectively. The agents to act upon the components of the sperm cell membrane such as the dithiothreitol and progesterone induced hyperpolarization and depolarization of the membrane 16% and 40%, respectively. The presence of propranolol and L-alpha-lysophosphatidylcholine, which affect the ionic gradients present across the plasma membrane, both induced a depolarization from 43% and 92% respectively. Finally, the addition of tetraphenylboron (TPB-) on the incubation medium, enhanced the value of the psi 75%. These studies are transcendent because with the utilization of agents depolarizing, or hyperpolarizing we obtain changes in the psi from -80 +/- 0.6 mV, until -6 +/- 0.6 mV changes of 74 +/- 1.5 mV across of the sperm cell membrane.

[Profile of the membrane potential of mammalian sperm during maturation, ejaculation and capacitation]

The accumulation of lipophilic cation radiolabeled tri-phenylmethyl phosphonium (TPMP+) was utilized to determine the resting membrane potential across the plasma membrane psi. Washed sperm of mammalian was suspended and incubated in low-K+ and high-K+ medium and allowed to take up the cation to a steady-state (20 min at 37 degrees C). By using this differential, the value obtained was transformed at value concentration using the intracellular volume and with these values inserted in the Nernst equation, we obtained the psi. During the maturation process the psi obtained in sperm cells of caput of the epididymis of New Zealand white rabbits was -75(+/-)-3 mV, in sperm cells of corpus and cauda, the psi obtained were -60(+/-)-5 and -52 +/- 3.5 mV, respectively. In the ejaculated spermatozoa the psi obtained was -69 +/- 2 mV. Finally, during the capacitation of human spermatozoa induced by the addition of calcium ions and the ionophore A23187 the psi obtained was -35 +/- 4 mV. These changes in the psi are significant because when the mammalian sperm cells are under different physiological conditions the membrane polarity is modified for the hyperpolarization and depolarization observed.

Hyperpolarization/depolarization on human spermatozoa

The accumulation of the lipophilic cation radiolabeled triphenylmethylphosphonium (TPMP+) was utilized to determine the resting membrane potential across the plasma membrane (psi) of human sperm. Washed sperm were suspended and incubated in low-K+ and high-K+ medium and allowed to take up the cation to a steady state (20 min at 37 degrees C). By using this differential, the value obtained was inserted in the Nernst equation and the value yielded a psi of -69 +/- 2 mV. When the Na+ or K+ concentration is high in the medium, the accumulation of TPMP+ in the membrane sperm cells was increased or decreased, respectively, inducing hyperpolarization and depolarization of the membrane 20% and 85%, respectively. The presence of divalent cations Zn++ and Mg++ in the incubation medium both induced a hyperpolarization of 10% and 8.6%, respectively. The addition of specific reagents such as p-chloromercuribenzenosulfonate and ethylenediaminetetraacetic acid sodium salt both decreased the psi 35% and 58%, respectively. The agents acting on the sperm cell membrane, such as dithiothreitol and progesterone, both induced hyperpolarization and depolarization of the membrane 16% and 40%, respectively. The presence of propranolol and L-alpha-lysophosphatidylcholine, which affect the ionic gradients present across the plasma membrane, both induced a depolarization from 43% and 92%, respectively. Finally the psi was glucose-dependent. The result of these studies was that, by the use of agents causing hyperpolarization or depolarization, we obtained changes in the psi of -83.4 +/- 2.2 mV, until -6 +/- 0.6 mV changes of -76.8 +/- 2 mV translated across the sperm cell membrane.

[Role of sialyltransferase and neuraminidase in the epididymis of rats]

The sialylation and desialylation in the rat epididiymis is the transference or remotion of sialic acid, to or from an adequate acceptor (glyco or sialogycoprotein). The sialylation of the glycoprotein or glycolipids is determinated by sialyltransferase activity; the homogenates from caput region showed 14 times more sialyltransferase activity than homogenates from cauda epididymis. The desialylation of the sialoglycoproteins is quantified by neuraminidase activity, and it can be observed that the homogenate from the caput zone shows 3 times more activity than homogenates from cauda epididymis. When relatione the activities of sialytransferase/neuraminidase of the caput zone and the cauda zone, the obtained values were 0.19 +/- 0.03 and 0.04 +/- 0.005, respectively. The relation between the activities of neuraminidase/sialiltransferase of the caput and the cauda zone showed the following valves: 5 +/- 0.6 and 25 +/- 3.3, respectively. The results have shown that sialylation is more active in the caput than in the cauda. Besides, while valvating the desialylation we observe that it is more effective in the cauda epididymis.

[Type-I and -II estradiol binding sites in the endometrium during blastocyst implantation]

The properties of type I and occupied and unoccupied type II cytosolic estrogen binding sites in the rat endometrium were analyzed on day five of pregnancy; the samples studied correspond to blastocyst receptive endometrium (implantation sites), nonreceptive endometrium and ovariectomized uterine horn endometrium, from the same pregnancy rats. The occupied binding site type II was analyzed by exchange assays. Dissociation constant obtained from experiments carried out at 4 or 25 degrees C are similar for each one of the binding site at the three different endometrium samples; the binding capacity (femtomoles/mg protein) from the sites type I and type II and the ratio between occupied (by endogenous estradiol) and unoccupied site type II, seems to be characteristic for each one of the three analyzed endometrium.

Effect of steroid hormones and capacitation on membrane potential of human spermatozoa

The accumulation of the lipophilic cation radiolabeled triphenylmethylphosphonium (TPMP+) was utilized to determine the resting membrane potential across the plasma membrane (psi) on human sperm. Washed sperm were suspended and incubated in low-K+ and high-K+ medium and allowed to take up the cation to a steady state (that is, 20 min at 37 degrees C). The data were transformed according to concentration using the intracellular volume and with these values inserted in the Nernst equation we obtain psi. When the concentration of K+ was low in the medium, the psi was -69 +/- 2 mV, the psi was temperature- and pH-dependent. The sperm were incubated in the same conditions in the presence of testosterone, estradiol, and progesterone. The addition of these hormones induced the decrease in psi by about 29%, 32%, and 40%, respectively. On the other hand, capacitation of spermatozoa was induced by the addition of calcium and the ionophore A23187 and in these conditions the psi decreased 50%. The action of the hormones on sperm membrane was accompanied by some steroid-dependent structural modification promoting the psi decrease. This effect plays an important role in the capacitation, preparing it for sperm penetration in the ova.

Microsomal and plasma membrane sialyltransferase activity in rat epididymis

3H-sialyl residues transfer by subcellular epididymal fractions [plasma membrane (PM), microsomes (MI), and mitochondria (MT)] to both endogenous and exogenous acceptors was studied. Their fraction purity was valued (5' nucleotidase and glucose 6-phosphatase activities). The glycoprotein or glycolipid N-acetyl neuraminyl transferase activity in microsomes were 5 times higher in caput than in cauda (624 to 125 pmoles/30 min/mg protein). PM activity also was higher in caput. In MT fraction, the activity was smaller. Two mechanisms related to spermatozoa glycoprotein changes during maturation are proposed: secretion to the lumen of molecules previously glycosilated in microsomes and transialylation to spermatozoa from membranal ectoenzymes localized on the surface of the epididymal epithelium.

Exchange of lipids between spermatozoa and seminal plasma in normal and pathological human semen

Normal and pathological semen were studied with regard to cholesterol and phospholipid content of sperm cells and seminal plasma. Spermatozoa from pathologic semen have similar concentrations of phospholipid-phosphorous and significantly higher cholesterol concentration than spermatozoa from normal semen. However, only oligoasthenospermic spermatozoa showed a significantly higher cholesterol/phospholipid ratio. Azoospermic seminal plasma showed the lowest values of both cholesterol and phospholipids, but the ratio of cholesterol to phospholipids was equal to that in normal spermatozoa. No significant difference was found in the cholesterol concentration of seminal plasma from oligoasthenospermic, asthenospermic, and normospermic subjects and only asthenospermic plasma showed a significantly lower concentration of this compound. Cholesterol and phospholipid exchange between sperm cells and seminal plasma was shown by the striking correlation between the lipid composition of seminal plasma with that of sperm cells.

Metabolic changes induced in human spermatozoa by subagglutinating concentrations of specific antibodies

The effects on sperm metabolism of subagglutinating concentrations of infertile female sera, containing antisperm antibody, were studied. Sera were selected by their differential agglutinating or immobilizing properties and by high titers of activity. Only the immobilizing antibodies were able to decrease sperm viability. Basal and succinate depending oxygen uptake, thus as progressive motility was decreased by sera producing mixed agglutination and more drastically by that producing immobilization independent of the presence of complement. The sera with head-to-head agglutination properties induced an increase in the above mentioned physiologic parameters. Tip of tail-to-tip of tail agglutinating sera having no effect on oxygen uptake were able to induce a significant increase in progressive motility. Conversion of 14C-Glucose to 14CO2 was decreased by sera that induced tip of tail-to-tip of tail agglutination and complement-independent immobilization. The sera which induced head-to=head agglutination and immobilization on the presence of complement, were without effect. None of the tested sera showed any acitivity over the conversion of 14C-Glucose to 14C-Lactate.

Glycemic response to 24-hour fast in normal children: III. Influence of age

A 24-hour fast was performed in 28 normal children-17 boys and 11 girls, 2 to 17 years of age. After the fast, blood was drawn for blood sugar, plasma growth hormone and cortisol, serum free fatty acids and alanine measurements. Blood sugar values ranged between 30 and 77 mg/dl and were significantly correlated to age (R = 0.68, P less than 0.001). Plasma cortisol (R = 0.73, P less than 0.001), GH (R = 0.57, P = 0.01), and FFA (R = 0.76, P less than 0.001) were negatively correlated to age. Serum alanine fasting values ranged between 10 and 36 micrometer/dl and were significantly correlated to age (R = 0.86, P less than 0.001) and to blood sugar values (R = 0.54, P less than 0.01). These data demonstrate that carbohydrate regulation during fast improves with age in children, correlating with higher levels of gluconeogenic substrates and a lower rate of lipolysis.