Dietary tannins from cowpeas and tea transiently alter apparent calcium absorption but not absorption and utilization of protein in rats

Tannins reportedly alter absorption and utilization of protein and minerals. The present study investigated the effect of tannins extracted from 'Mississippi Silver' cowpeas and black tea when incorporated into nutritionally balanced diets. Condensed tannins were incorporated into the diet of weanling male Sprague-Dawley rats at 0.0, 0.0057, 0.0171 and 0.057 g/100 g diet for 28 d. Ingestion of tannin from cowpeas or tea did not change significantly growth rate, protein efficiency ratio, apparent protein digestibility, nitrogen excretion, relative liver weight, or nitrogen concentration of liver. During d 11-18, apparent calcium absorption was lower in rats fed the medium and high levels of cowpea tannin and in those fed all levels of tea tannin compared with the control group. By wk 4, no differences were observed in apparent calcium absorption among treatment groups. Apparent magnesium absorption was not affected by dietary treatment, nor was femur content of calcium or magnesium. We conclude that at the levels of condensed tannins fed, a short-term reduction of apparent calcium absorption occurred; however, by wk 4 calcium absorption was comparable to that of the control group. The acute change that occurred in apparent calcium absorption did not influence bone calcium content.

In vivo effect of a thrombin-like enzyme on platelet plug formation induced in mesenteric microvessels of mice

Ancrod caused defibrinogenation and exhibited ex vivo antiplatelet activity in experimental rabbits. In this study, platelet thrombus was induced by irradiation of the mesenteric microvessels with filtered light in mice pretreated with fluorescein sodium intravenously. Ancrod (0.5-2 U/kg) dose-dependently, significantly prolonged the time lapse of inducing platelet plug formation in mesenteric venules when it was intravenously infused. At these doses, ancrod depleted plasma fibrinogen and displayed ex vivo antiplatelet aggregation induced by collagen. Ancrod (1 U/kg) prolonged the occlusion time about 2.1 folds (from control 103.2 +/- 17.0 to 211.2 +/- 26.3 seconds) with a duration longer than 60 min. On the other hand, PGI2 briefly prolonged the occlusion time about 1.5 folds when it was given by continuous infusion (250-500 ng/kg/min). Heparin (100-250 U/kg) had no significant effect in this model. Therefore, ancrod may be used as a therapeutic agent not only in treatment of venous thrombosis and possibly in prevention of arterial thrombosis.

Purification and characterization of L-aminoacylase from Alcaligenes denitrificans DA181

The L-aminoacylase produced intracellularly by Alcaligenes denitrificans DA181 was purified to homogeneity. This enzyme had an apparent molecular weight of 80,000, and was composed of two subunits of identical molecular weight. Its isoelectric point was pH 5.1. The optimal reaction temperature and pH were 65 degrees C and 8.0, respectively. This enzyme showed specificity toward N-acetyl-derivative of hydrophobic L-amino acids with N-acetyl-L-valine as the favored substrate, followed by N-acetyl-L-alanine.

A retrospective study of DNA ploidy of transitional cell carcinoma of urinary bladder using flow cytometry

Transitional cell carcinoma is the most common malignancy of urothelial origin in urinary bladder. Its aggressive potential cannot be reliably predicted from the histologic appearance alone. Recently, there has been extensive studies of DNA ploidy using flow cytometry in prospective analysis of bladder tumors with fresh tissue. Techniques for the preparation of paraffin embedded tissue have been developed and successfully applied in retrospective evaluation of bladder tumors. These studies had demonstrated the correlation between histological grading and DNA ploidy, and between clinical staging and DNA ploidy. Our retrospective study showed that the cytometric method is superior to histologic grading in the predictability of patient's survival, especially in the low grade (grades 1 and 2) group. In the preparation of paraffin embedded tissue, the high background debris and wide range of coefficients of variation had some interference in the interpretation for the histogram of FCM (only 80% of the cases studied are interpretable). This interference might be due to the variation of conditions of tissue processing and fixation. The evaluation of S phase fraction and G2/M fraction is also difficult to perform because of the same problem. There was an encouraging result in the evaluation of DNA ploidy using flow cytometry with paraffin embedded tissue, although a relatively small number of patients were included in this study. The value of this technique application in clinical evaluation of the prognosticity was obvious.

Cloning and nucleotide sequence of an extracellular alpha-amylase gene from Aeromonas hydrophila MCC-1

A gene encoding the extracellular alpha-amylase of Aeromonas hydrophila MCC-1 was cloned and expressed using its own promoter on the recombinant plasmid pCA101. Subcellular fractionation of Escherichia coli JA221 carrying pCA101 revealed that approximately 60% of the amylase activity was localized in the periplasmic space. The extracellular amylase was purified to homogeneity, identified as an alpha-type and its amino-terminal sequence was determined. Nucleotide sequence analysis predicted a 443 amino acid ORF and 24 amino acids at the amino terminus of the sequence that are not found in the secreted protein. This 24 amino acid sequence has many of the characteristics common to known signal peptides. The predicted amino acid sequence has considerable similarity with mammalian, invertebrate and Streptomycete alpha-amylases. Most of the amino acid residues that are involved in catalytic activity, substrate binding and calcium binding in several alpha-amylases were also present in A. hydrophila alpha-amylase at the corresponding positions.

Evidence for a cannabinoid receptor in sea urchin sperm and its role in blockade of the acrosome reaction

Delta-9-tetrahydrocannabinol ((-)delta 9 THC), the primary psychoactive cannabinoid in marihuana, reduces the fertilizing capacity of sea urchin sperm by blocking the acrosome reaction that normally is stimulated by a specific ligand in the egg's jelly coat. The bicyclic synthetic cannabinoid [3H]CP-55,940 has been used as a ligand to demonstrate the presence of a cannabinoid receptor in mammalian brain. We now report that [3H]CP-55,940 binds to live sea urchin (Strongylocentrotus purpuratus) sperm in a concentration, sperm density, and time-dependent manner. Specific binding of [3H]CP-55,940 to sperm, defined as total binding displaced by (-)delta 9THC, was saturable: KD 5.16 +/- 1.02 nM; Hill coefficient 0.98 +/- 0.004. This suggests a single class of receptor sites and the absence of significant cooperative interactions. Sea urchin sperm contain 712 +/- 122 cannabinoid receptors per cell. Binding of [3H]CP-55,940 to sperm was reduced in a dose-dependent manner by increasing concentrations of CP-55,940, (-)delta 9THC, and (+)delta 9THC. The rank order of potency to inhibit binding of [3H]CP-55,940 to sperm and to block the egg jelly stimulated acrosome reaction was: CP-55,940 > (-)delta 9THC > (+)delta 9THC. These findings show that sea urchin sperm contain a stereospecific cannabinoid receptor that may play a role in inhibition of the acrosome reaction. The radioligand binding data obtained with live sea urchin sperm are remarkably similar to those previously published by other investigators using [3H]CP-55,940 on mammalian brain and nonneural tissues. The cannabinoid binding properties of this receptor appear to have been highly conserved during evolution. We postulate that the cannabinoid receptor may modulate cellular responses to stimulation.

Antiplatelet protease, kistomin, selectively cleaves human platelet glycoprotein Ib

Kistomin, a metalloprotease purified from venom of Calloselasma rhodostoma, dose- and time-dependently prolonged the latent period of aggregation and inhibited ATP secretion of human washed platelets stimulated by thrombin. It inhibited aggregation induced by low concentrations of thrombin (< or = 0.2 U/ml) whereas it had only slight effect on aggregation induced by high concentrations of thrombin (> or = 0.5 U/ml). Meanwhile it also inhibited ristocetin-induced platelet aggregation in a dose- and time-dependent manner. It significantly inhibited cytosolic calcium rise of Quin 2--loaded platelets, completely blocked thromboxane B2 formation, and blocked [3H]inositol phosphates formation of [3H]myoinositol loaded platelets stimulated by 0.1 U/ml of thrombin. Kistomin inhibited significantly thromboxane but not [3H]inositol phosphates formation of platelets stimulated by a high concentration of thrombin (1 U/ml). Incubation of platelets with kistomin resulted in a selective cleavage of platelet membrane glycoprotein Ib as revealed by SDS/PAGE stained by periodic acid/Schiff reagent. These results suggested that thrombin activates platelets at least through two receptors/or effectors-mediated events. In addition to glycoprotein Ib, other surface membrane component(s) (e.g., the seven transmembrane domain thrombin receptor) may also be important in regulating the biochemical events of human platelets in response to thrombin. However, the extent and rate of platelet aggregation stimulated by low concentrations of thrombin ( < or = 0.2 U/ml) are closely related with the intactness of glycoprotein Ib.

[The immediate interpretation for fine-needle aspiration cytology]

From December 1990 to November 1992, 2005 cases of immediate interpretation for fine-needle aspiration (FNA) cytology were performed, of which 727 cases were confirmed by surgical pathology. A mobile cytologic laboratory (a cart loaded with a dual viewing microscope, Liu's staining solutions, hair dryer, and slides) can be moved to the Out-patient Department, wards and Computed Tomography room, where clinicians perform aspiration and pathologists read smears. Immediate verbal diagnoses are documented to patients' charts and listed in cytopathologic files. Immediate interpretation in this entire series yielded a sensitivity 92.5%; specificity, 98.1%; false-positive rate, 1.1%; false-negative rate, 3.2%; positive predictive value (PV), 97.3%; negative PV, 94.7% and efficiency, 95.7%. The cause of false-negative results in the 23 cases probably came from the hesitation in making an immediate diagnosis. Most of these cases were malignant lymphoma or breast carcinoma. The roles of immediate cytodiagnosis are (1) to decrease the inadequate rate of FNA specimens; (2) to render preliminary diagnosis for clinicians to make decisions; (3) to provide on-site teaching material for both clinicians and pathology residents to better understand clinicopathological correlations; (4) to act as the initial diagnostic procedure in the evaluation of a superficial palpable mass. This study shows that immediate interpretation for FNA cytology is a simple, rapid, accurate and noninvasive diagnostic procedure that can be routinely used for superficial palpable masses.

Percutaneous transcatheter treatment of an intracavitary aspergilloma

We describe a case of massive hemoptysis, secondary to an intracavitary aspergilloma, successfully treated by computed tomography (CT)-guided placement of a Cope-loop catheter with daily transcatheter instillation of amphotericin B and cavitary irrigation. Over a 15-day period, this regimen resulted in cessation of hemoptysis and radiographic resolution of the aspergilloma. No complications were encountered. A follow-up CT of the thorax showed no recurrence of the aspergilloma at 3 months.

[Intraoperative cytology: the use of Liu's stain for immediate diagnosis]

We prospectively studied 305 fresh specimens submitted for intraoperative frozen section diagnosis. Three types of cytologic preparations, namely touch imprint, smearing, and crush method, were performed to obtain adequate material. Liu's stain, which takes only two minutes and is one of the rapid staining methods of the Romanowsky series, was used for immediate interpretation. The accuracy of diagnosis was measured by comparison with final histological diagnosis. Sensitivity and specificity of intraoperative cytology were 94.9% and 95.6% respectively. The false-positive rate, false-negative rate, and suspicious rate were 0.3%, 1.3%, and 1.6%. In combination of intraoperative cytology and frozen section, sensitivity and specificity became 96% and 96.3% respectively. The cytomorphology of breast, thyroid, lymph node, and ovary is briefly described. Most cases of cytological diagnostic error are found in sarcomas and ovarian tumors. We conclude that Liu's stain is a simple, rapid, and reliable staining method in intraoperative cytological diagnosis. It is apparent that intraoperative cytology is able to provide a useful adjunct to the frozen-section diagnosis and an excellent teaching file for cytopathology.

Primary malignant lymphoma of the breast: report of two cases with literature review

We report two cases of malignant lymphoma of the breast. Extensive investigation on both, demonstrated only a neoplastic lesion confined within the breast. One was managed by local excision, systemic chemotherapy and adjuvant radiotherapy; the other was managed by a modified radical mastectomy, adjuvant radiotherapy and therapeutic chemotherapy. Both of them achieved complete remission 3 years and 1.5 years respectively after management.

Base deficit as a guide to injury severity and volume resuscitation

Base deficit is an expeditious and sensitive measure of both the degree and duration of inadequate perfusion, and has utility in the clinical evaluation and management of victims of trauma. It is rapid, accurate, and widely available, and as such may be very useful in the initial evaluation of these patients; it may also be used to help guide and assess the adequacy of volume resuscitation. It has in addition both clinical value and research potential in predicting outcome in these patients, and may be a useful tool to both the clinician and the researcher.

A novel alpha-type fibrinogenase from Agkistrodon rhodostoma snake venom

By means of CM-Sephadex C-50 column chromatography, gel-filtration on sephadex G-75 and Sephacryl S-200 columns, a purified fibrinogenase, kistomin, was obtained from venom of Agkistrodon rhodostoma. It was a single peptide-chain with a molecular mass of about 21,800 Da containing about 202 amino-acid residues as revealed by amino acid analysis. Kistomin preferentially cleaved A alpha- and subsequently the gamma-chain of fibrinogen, leaving the B beta-chain unaffected. Its fibrinogenolytic activity was estimated to be 36.6 +/- 4.5 mg/min per mg protein and was inhibited by the pretreatment of EDTA, suggesting that it is a metalloproteinase. Its fibrinogenolytic activity in platelet-poor plasma is much less potent as compared to that in purified fibrinogen solution. It inhibited ristocetin-induced aggregation of human platelets in a dose-dependent manner in the presence of von Willebrand factor.

Cloning and expression in Escherichia coli of the gene encoding an extracellular deoxyribonuclease (DNase) from Aeromonas hydrophila

The gene encoding an extracellular DNase from Aeromonas hydrophila CHC-1 has been cloned and sequenced. Following expression of the dns in Escherichia coli, it was revealed that some of the cloned enzyme was present in the cell-free extracellular supernatant fluid, and there was no cell lysis and concurrent release of cytoplasmic or periplasmic proteins. Therefore, results suggest that E. coli cells were capable of secreting the DNase extracellularly, albeit very inefficiently. The dns is transcribed from its own promoter in E. coli, and expressed as a 25-kDa product, as determined by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis of the culture supernatant preparations followed by a DNA-hydrolysis assay. Nucleotide sequence analysis predicted a single open reading frame of 690 bp encoding a 230-amino acid (aa) polypeptide, with a potential 20-aa signal peptide located at the N terminus of the predicted protein. The deduced aa sequence of the entire protein is highly homologous with that of the DNase of Vibrio cholerae.

Cloning of a creatinase gene from Pseudomonas putida in Escherichia coli by using an indicator plate

A genomic library of Pseudomonas putida DNA was constructed by using plasmid pBR322. Transformants of Escherichia coli in combination with Proteus mirabilis cells grown on creatinase test plates were screened for creatinase activity; transformants were considered positive for creatinase activity if a red-pink zone appeared around the colonies. One creatinase-positive clone was further analyzed, and the gene was reduced to a 2.7-kb DNA fragment. A unique protein band (with a molecular weight of approximately 50,000) was observed in recombinant E. coli by minicell analysis.

[A comparison of transrectal fine needle aspiration and biopsy of prostatic lesion]

Transrectal fine needle aspiration and biopsy were performed on 100 patients with suspicious prostatic lesions using 22 gauge aspiration needles and 18 gauge biopsy needles. These collections were made from January 1990 to June 1991. Sufficient prostate tissue for cytological and histological diagnosis were obtained in 97% (97/100) and 99% (99/100), respectively. Thirty-nine patients (39%) were diagnosed having cancer with an accuracy rate of 89.7% (35/39) by histology and 69.2% (27/39) by cytology. One patient with a normal cytological aspiration was found to have an atypical biopsy, therefore, the biopsy was repeated and the prostate showed adenocarcinoma. Our results indicate that the needle aspiration cytology has a less accurate diagnosis rate than the needle biopsy histology. Fine needle aspiration is a safe and effective outpatient procedure but there is a definite learning curve before its use can be fully exploited. It is important to have experienced urologists and pathologists to perform these aspirations until sufficient experience is accumulated.

[Autonomic nerve preserving operation for rectal carcinoma: preliminary postoperative urinary function of 15 cases]

The autonomic nerve preserving operation was performed on 15 patients with rectal carcinoma (9 men and 6 women), from August 1990 to February 1991. The average age was 57.2 years ranging from 28 to 70 years. Low anterior resection was performed on 6 patients having middle rectal carcinoma. Seven Colonic anastomosis and two abdominoperineal resections were performed for lower rectal carcinoma. The average operation time was 4 hours and 22 minutes. The average blood loss was 1560 cc. Urinary functions were evaluated pre- and post-operatively. None of the patients needed re-catheterization postoperatively. Urodynamic studies showed no significant differences. We recommend this operation for rectal cancer because it prevented the postoperative autonomic dysfunction without affecting the curability.

DNA content in correlation with postsurgical stage in non-small cell lung cancer

The relationship between DNA content, TNM stage, tumor size, grade, histology, and disease-free survival was assessed in a retrospective study of patients with non-small cell lung cancer who had undergone resection and complete mediastinal lymph node dissection. Flow cytometric analysis was performed on paraffin-embedded tissue of 90 consecutive patients. The patients were analyzed both as a group and by individual stage. Median follow-up was 11 months (range, 1 to 35 months). Aneuploid tumors were not significantly different from diploid tumors with regard to pathologic TNM stage (p = 0.34), size (p = 0.5), grade (p = 0.5), or histology (p = 0.34). Disease-free survival of patients with aneuploid tumors was not significantly different than that of patients whose tumors had normal DNA content (p = 0.69). DNA content did not correlate with established prognostic factors in patients with non-small cell lung cancer who underwent resection and complete mediastinal lymph node dissection.

Cannabinoids inhibit fertilization in sea urchins by reducing the fertilizing capacity of sperm

Delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) inhibit fertilization in the sea urchin Strongylocentrotus purpuratus by reducing the fertilizing capacity of the sperm. Sperm fertility depends upon their motility, and their capacity to undergo the acrosome reaction upon encountering a specific ligand derived from the egg's jelly coat. The acrosome reaction involves exocytosis of the acrosomal granule at the apex of the sperm head and elongation of the acrosomal filament. This process exposes the sperm membrane that will attach to and fuse with the egg. Pretreatment of sperm with THC prevents the triggering of the acrosome reaction by solubilized egg jelly in a dose and time dependent manner. Motility of THC-treated sperm is not reduced compared to control sperm in sea water or vehicle dissolved in sea water. The adverse effects of THC on the acrosome reaction and sperm-fertilizing capacity are reversible. Studies with ionophores suggest that THC blocks the acrosome reaction by affecting event(s) in the stimulation-secretion coupling mechanism in the sperm preceding the opening of ion channels. Ultrastructural studies show that THC, CBD and CBN block the membrane fusion reaction between the sperm's plasma membrane and the acrosomal membrane that normally is elicited in response to stimulation by egg jelly to initiate the acrosome reaction. However, lipid deposits are found in the subacrosomal and centriolar fossae of cannabinoid treated sperm. The nuclear envelope is fragmented in close proximity to the lipid deposits within the subacrosomal fossa. These morphological observations suggest that cannabinoids may activate phospholipase(s) within the sperm. Biochemical studies show that THC activates phospholipase A2 activity in sperm homogenates.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning and expression of a chitinase gene from Aeromonas hydrophila in Escherichia coli

An extracellular secreted chitinase gene from Aeromonas hydrophila was cloned in Escherichia coli, and the gene product was detected in the culture medium. Like the natural chitinase protein, the excreted chitinase had a molecular weight of approximately 85,000 and was subject to catabolite repression by glucose.

Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. III. Activation of phospholipase A2 in sperm homogenate by delta 9-tetrahydrocannabinol

Inhibition of the egg jelly induced acrosome reaction by delta 9-tetrahydrocannabinol (THC) is associated with the localized disruption of the nuclear envelope and the formation of lipid deposits in sea urchin sperm. This suggests that THC may activate phospholipase(s) within the sperm. We now report effects of THC on phospholipase A2 activity in homogenates of sea urchin sperm using 1-stearoyl-2-[1-14C]arachidonyl phosphatidylcholine as substrate. The release of radioactive arachidonic acid was measured after a 30-min incubation with the enzyme. In the absence of exogenous Ca2+, 100 microM THC produced a significant (P less than 0.001) increase in phospholipase A2 activity. THC activated phospholipase A2 in a concentration (1-100 microM) and time-dependent (0-30 min) manner. Exogenous calcium (10 mM) significantly augmented basal (P less than 0.001) and THC-stimulated (P less than 0.005) phospholipase A2 activity. Calcium chelators [ethylene glycol bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA) and 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)] inhibited the basal level of phospholipase A2 activity in the sperm homogenate, and prevented the activation of phospholipase A2 by THC. Submicromolar levels of free calcium ions were required for THC stimulation of phospholipase A2. Cannabinol which mimics the effects of THC on the acrosome reaction also activated phospholipase A2 in sperm homogenate. These results suggest that THC may alter lipid metabolism in sperm by activating calcium-dependent phospholipase A2. Putative metabolites derived from this process may inhibit the acrosome reaction and thereby reduce the fertilizing capacity of sea urchin sperm.

Fluorescence polarization and low-temperature absorption spectroscopy of a subunit form of light-harvesting complex I from purple photosynthetic bacteria

Measurements of polarized fluorescence and CD were made on light-harvesting complex 1 and a subunit form of this complex from Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodobacter capsulatus. The subunit form of LH1, characterized by a near-infrared absorbance band at approximately 820 nm, was obtained by titration of carotenoid-depleted LH1 complexes with the detergent n-octyl beta-D-glucopyranoside as reported by Miller et al. (1987) [Miller J. F., Hinchigeri, S. B., Parkes-Loach, P. S., Callahan, P. M., Sprinkle, J. R., & Loach, P. A. (1987) Biochemistry 26, 5055-5062]. Fluorescence polarization and CD measurements at 77 K suggest that this subunit form must consist of an interacting bacteriochlorophyll a dimer in all three bacterial species. A small, local decrease in the polarization of the fluorescence is observed upon excitation at the blue side of the absorption band of the B820 subunit. This decrease is ascribed to the presence of a high-energy exciton component, perpendicular to the main low-energy exciton component. From the extent of the depolarization, we estimate the oscillator strength of the high-energy component to be at most 3% of the main absorption band. The optical properties of B820 are best explained by a Bchl a dimer that has a parallel or antiparallel configuration with an angle between the Qy transition dipoles not larger than 33 degrees. The importance of this structure is emphasized by the results showing that core antennas from three different purple bacteria have a similar structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. II. Ultrastructural changes associated with inhibition of the acrosome reaction

Pretreatment of Strongylocentrotus purpuratus sperm with delta 9-tetrahydrocannabinol (THC) prevents the triggering of the acrosome reaction by egg jelly. Examination of THC-treated sperm by transmission electron microscopy reveals that the membrane fusion reaction between the sperm plasma membrane and the acrosomal membrane is completely blocked. Electron-dense deposits are present in the subacrosomal fossa and in the centriolar fossa. The nuclear envelope is fragmented in close proximity to the electron-dense deposits. The electron-dense deposits are not bound by a limiting membrane, stain positively for lipid with thymol and farnesol, and disappear from THC-treated sperm that are extracted with chloroform:methanol (2:1) after glutaraldehyde fixation. The electron-dense deposits are lipid in nature and may be a hydrolytic product of the nuclear envelope. Electron-dense deposits are seen in sperm after 1-10 min treatment with 5-100 microM THC. The electron-dense deposits disappear after removal of THC from the sperm by washing, but the fragmented nuclear envelope in the subacrosomal fossa persists. Cannabidiol (CBD) and cannabinol (CBN) also inhibit the triggering of the acrosome reaction by egg jelly and produce ultrastructural changes in the sperm identical to those elicited by THC. Enhanced phospholipase activity stimulated by THC, CBD, and CBN may be the cause of the accumulation of lipid deposits in the sperm. Metabolites derived from this modification of membrane phospholipids may prevent triggering of the acrosome reaction by egg jelly and thereby inhibit fertilization.

Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. I. Inhibition of the acrosome reaction induced by egg jelly

delta 9-Tetrahydrocannabinol (THC) and two other major cannabinoids derived from marihuana--cannabidiol (CBD) and cannabinol (CBN)--inhibit fertilization in the sea urchin Strongylocentrotus purpuratus by reducing the fertilizing capacity of sperm (Schuel et al., 1987). Sperm fertility depends on their motility and on their ability to undergo the acrosome reaction upon encountering the egg's jelly coat. Pretreatment of S. purpuratus sperm with THC prevents triggering of the acrosome reaction by solubilized egg jelly in a dose (0.1-100 microM) and time (0-5 min)-dependent manner. Induction of the acrosome reaction is inhibited in 88.9 +/- 2.3% of sperm pretreated with 100 microM THC for 5 min, while motility of THC-treated sperm is not reduced compared to solvent (vehicle) and seawater-treated controls. The acrosome reaction is inhibited 50% by pretreatment with 6.6 microM THC for 5 min and with 100 microM THC after 20.8 sec. CBN and CBD at comparable concentrations inhibit the acrosome reaction by egg jelly in a manner similar to THC. THC does not inhibit the acrosome reaction artificially induced by ionomycin, which promotes Ca2+ influx, and nigericin, which promotes K+ efflux. THC partially inhibits (20-30%) the acrosome reaction induced by A23187, which promotes Ca2+ influx, and NH4OH, which raises the internal pH of the sperm. Addition of monensin, which promotes Na+ influx to egg jelly or to A23187, does not overcome the THC inhibition. Inhibition of the egg jelly-induced acrosome reaction by THC produces a corresponding reduction in the fertilizing capacity of the sperm. The adverse effects of THC on the acrosome reaction and sperm fertility are reversible.(ABSTRACT TRUNCATED AT 250 WORDS)