Neuroprotective effects of Nigella sativa on experimental spinal cord injury in rats

The aim of this study was to investigate the possible beneficial effects of Nigella sativa (NS) in comparison to methylprednisolone on experimental spinal cord injury (SCI) in rats. SCI was performed by placing an aneurysm clip extradurally at the level of T11-12. Rats were neurologically tested over 24 h after trauma and spinal cord tissue samples were harvested for both biochemical and histopathological evaluation. The neurological scores of rats were not found to be different in SCI groups. SCI significantly increased the spinal cord tissue malondialdehyde (MDA) and protein carbonyl (PC) levels, however SCI decreased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities compared to the control. Methylprednisolone and NS treatment decreased tissue MDA and PC levels and prevented inhibition of SOD, GSH-Px and CAT enzymes in the tissues. The most significant results were obtained when NS was given. In SCI and placebo groups, the neurons of spinal cord tissue became extensively dark and degenerated with picnotic nuclei. The morphology of neurons in methylprednisolone and NS-treated groups were well protected, however, not as well as the neurons of the control group. The number of neurons in the spinal cord tissue of the SCI and placebo groups was significantly less than the control, laminectomy, methylprednisolone and NS-treated groups. In conclusion, NS treatment might be beneficial in spinal cord tissue damage, and therefore shows potential for clinical implications.

Effects of Low Intensity Exercise Against Apoptosis and Oxidative Stress in Streptozotocin-induced Diabetic Rat Heart

Background The aim of this study was to investigate the effects of low intensity exercise on heart of streptozotocin (STZ)-induced diabetic rats. Materials and Methods The rats were randomly divided into 3 experimental groups: A (control), B (diabetic untreated), and C (diabetic treated with low intensity exercise); each group contains 8 animals. B and C groups received STZ. Diabetes was induced in 2 groups by a single intraperitoneal (i.p) injection of STZ (40 mg/kg, freshly dissolved in 0,1 M citrate buffer, pH 4.2). 2 days after STZ treatment, diabetes in 2 experimental groups was confirmed by measuring blood glucose levels. Rats with blood glucose levels of 250 mg/dl or higher were considered to be diabetic. Animals in the exercise group were made to run the treadmill once a day for 4 consecutive weeks. Exercise started 3 days prior to STZ administration. Results After induction of diabetes, histological abnormalities were observed, including myofibrillar loss, vacuolization of cytoplasm and irregularity of myofibrils. These alterations were attenuated by low intensity exercise. Our data indicates a significant reduction of oxidative stress and apoptosis in cardiomyocytes after exercise. Treatment of diabetic animals with low intensity exercise, decreased the elevated tissue malondialdehyde (MDA) levels and increased the reduced activities of the enzymatic antioxidants superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in cardiac tissue. Conclusion These findings suggest that low intensity exercise has a therapeutic protective effect in diabetes by decreasing oxidative stress and apoptosis, and by preservation of myocardial integrity.

The effects of quercetin on liver regeneration after liver resection in rats

The aim of the present study was to assess the influence of quercetine (QE) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Wistar albino rats were divided into three groups: sham-operated (SH), PH and PH+QE; each group contain 8 animals. The rats in QE-treated groups were given QE (15 mg/kg body weight) once a day i.p., for 7 days starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labelling, proliferation index (PI), transferase-mediated dUTP nick end-labelling assay, apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, QE significantly increased MI, PI, and significantly decreased AI in PH rats. Additionally, QE remarkably inhibited the elevation of MDA, restored impaired antioxidant SOD activity and GSH level, and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that QE treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic and proliferative property.

Investigation of telomerase activity and apoptosis on invasive ductal carcinoma of the breast using immunohistochemical and Western blot methods

OBJECTIVE

Invasive ductal carcinoma (IDC) comprises the largest group of breast cancers. This study aimed to investigate telomerase activity and apoptosis using immunohistochemical and Western blot methods.

PATIENTS AND METHODS

In total, 75 cases that had been diagnosed as IDC and 20 cases that had undergone a freezing procedure were included. The histological sections were stained with Bax, Bcl-2, hTERT and BNIP3. The ages of the patients, as well as their hormonal status and tumour sizes and grades were evaluated, as well as the staining characteristics of the antibodies in question.

RESULTS

A decrease in Bcl-2 positivity and an increase in Bax positivity were found immunohistochemically with increasing tumour grades. The data obtained by western blot method showed that Bcl-2 was highest in grade 1 tumours although these results were not statistically significant. The relationship between estrogen and progesterone receptor positivity and Bcl-2 was statistically significant, suggesting there is hormonal control through apoptosis. BNIP3 was found to be decreased with increasing tumour grades. Similarly, BNIP3 was found to be having the lowest value in grade 3 tumours by western blot method. Furthermore, hTERT was found to be increased with increasing tumour grades. In the western blot method, hTERT increased nearly four-fold compared to the control. In addition, hTERT, which was seen in very high levels in tumours, may be a helpful cancer marker. Both hTERT and BNIP3 are important markers that can provide information about prognosis.

CONCLUSIONS

Big improvements can be achieved in tumour progression control with new treatment modalities that stop telomerase activity and hypoxic cell death.

The role of ionizing radiaton on ovulation rate and oocyte morphology in mouse

We investigated the effects of ionizing radiation on maturation ability and radiosensitivity of oocytes enclosed in preantral and antral follicles. Balb/c female mice received total body single dose gamma radiation (7.2 Gy) at the diestrous to proestrous transition period. In the first experiment, spontaneously ovulated oocytes were collected from irradiated animals. In the second experiment, irradiated animals were allowed to superovulate to assess the ovarian function. The spontaneous ovulation rate of the follicles exposed at antral stage was significantly lower than the sham-irradiated mice (p < 0.01), and most of the oocytes were found at the metaphase I stage. Oocyte morphology and the ovulation rate of the follicles exposed at preantral stage were similar to the sham-irradiated group. Minimal morphological abnormalities were observed in the oocytes and the polar body as well. The superovulation response of all the irradiated animals was lower than the respective control animals. The superovulation rate was significantly lower in the first ovulation after irradiation (p < 0.01). In conclusion, our findings indicate that total body gamma irradiation, on a basis of estrous cycle stages, leads to ovulation failure in the antral stage while causes abnormal oocyte morphology in the preantral stage follicles in mice.

Protective effects of quercetin on testicular torsion/detorsion-induced ischaemia-reperfusion injury in rats

The aim of this study was to investigate the protective effect of quercetin (QE) on testicular torsion/detorsion-induced ischaemia-reperfusion (I/R) injury. A total of 24 male Wistar albino rats were divided into three groups: control, I/R and I/R treated with QE; each group contain eight animals. Testicular torsion was created by rotating the left testis 720° in a clockwise direction. The ischaemia period was 5 h and orchiectomy was performed after 5 h of detorsion. QE (15 mg kg(-1) , i.p.) was administered only once, 40 min prior to detorsion. Left orchiectomy was performed in all I/R groups. To date, no histopathological changes on testicular torsion/detorsion-induced I/R injury in rats by QE treatment have been reported. Spermatogenesis and mean seminiferous tubule diameter were significantly decreased in I/R groups were compared with the control group. Furthermore, QE treated animals showed an improved histological appearance in I/R group. Our data indicate a significant reduction in the activity of TUNEL, endothelial nitric oxide synthase and a rise in the expression of testosterone in testes tissue of I/R treated with QE therapy. We believe that further preclinical research into the utility of QE may indicate its usefulness as a potential treatment on testes injury after I/R in rats.

Influence of a combination of formic and propionic acids added to wheat- and barley-based diets on the performance and gut histomorphology of broiler chickens

Day-old male chicks were used to test the effects of a combination of formic and propionic acids (CFP) added to wheat- and barley-based diets on the performance and gut histomorphology of broilers. The CFP, containing formic and propionic acids based on an inorganic phyllo-silicate carrier, was added to starter and grower broiler diets of standard (NRC, 1994) or lower nutrient density (LND) using different levels of wheat and barley. Body weight gain (BWG) and feed conversion ratio (FCR) of broiler chicks were significantly (P < 0.001) improved by CFP supplementation at 21 days of age regardless of nutrient density (ND). However, at 35 days of age CFP addition significantly (P < 0.001) increased BWG and FCR. Proventriculus weight was also significantly affected by the dietary treatments. Ileal viscosity was significantly (P < 0.05) affected by ND which was associated with wheat and barley contents, whereas feed viscosity was significantly (P < 0.05) affected by CFP supplementation. Villus height was significantly (P < 0.05) increased by the CFP supplementation. In the case of villus width, an interaction effect was observed: there was a significant (P < 0.05) decrease in the group fed the standard ND diet, but only a numerical decrease in the group fed the LND diet compared to control group. No significant effect of dietary treatment on the thickness of the lamina muscularis mucosae could be detected.

Vitamin E protects against acetone-induced oxidative stress in rat red blood cells

Acetone may induce oxidative stress leading to disturbance of the biochemical and physiological functions of red blood cells (RBCs) thereby affecting membrane integrity. Vitamin E (vit E) is believed to function as an antioxidant in vivo protecting membranes from lipid peroxidation. The aim of the present study was the evaluation of possible protective effects of vit E treatment against acetone-induced oxidative stress in rat RBCs. Thirty healthy male Wistar albino rats, weighing 200-230 g and averaging 12 weeks old were randomly allotted into one of three experimental groups: Control (A), acetone-treated (B) and acetone + vit E-treated groups (C), each containing ten animals. Group A received only drinking water. Acetone, 5% (v/v), was given with drinking water to B and C groups. In addition, C group received vit E dose of 200 mg/kg/day i.m. The experiment continued for 10 days. At the end of the 10th day, the blood samples were obtained for biochemical and morphological investigation. Acetone treatment resulted in RBC membrane destruction and hemolysis, increased thiobarbituric acid reactive substance (TBARS) levels in plasma and RBC, and decreased RBC vit E levels. Vit E treatment decreased elevated TBARS levels in plasma and RBC and also increased reduced RBC vit E levels, and prevented RBC membrane destruction and hemolysis. In conclusion, vit E treatment appears to be beneficial in preventing acetone-induced oxidative RBC damage, and therefore, it can improve RBC rheology.

Effect of thyroidectomy on the histology of rat sublingual gland

This study was carried out to investigate the effect of thyroidectomy on the histology of rat sublingual gland. Twenty-eight male Wistar albino rats, aged 4 weeks and weighing between 45-55 g, were used. The rats were divided into two experimental groups (control and thyroidectomy), each containing 14 animals. Total thyroidectomy of rats was performed under ether anesthesia in thyroidectomy group. The rats in the control group were sham operated without having the thyroidectomy. Seven rats randomly selected from both groups were fixed using the perfusion fixation technique 2 and 6 weeks after thyroidectomy, and their sublingual glands were harvested for histological investigation. No histological difference was observed between the two groups 2 weeks after thyroidectomy. However, 6 weeks after thyroidectomy considerable cytoplasmic vacuolization of the epithelial cells of the mucous tubules was seen in the thyroidectomy group compared to the controls. Enlargement of mucous tubules was also observed, and the lumina in most of the tubules was quite dilated. In the stroma surrounding the parenchymal tissues, increased lipid tissue mass was observed. In addition, increased connective tissue mass and mononuclear cell infiltrations were evident. Furthermore, the number of mast cells was significantly higher in the thyroidectomy group than in the controls 6 weeks after thyroidectomy. It was concluded that the thyroid gland and hormones might have an influence on the histology of the sublingual gland.

Effects of Nigella sativa L. and Urtica dioica L. on Lipid Peroxidation, Antioxidant Enzyme Systems and Some Liver Enzymes in CCl4-Treated Rats

This study was designed to investigate the effects Nigella sativa L. (NS) and Urtica dioica L. (UD) on lipid peroxidation, antioxidant enzyme systems and some liver enzymes in carbon tetrachloride (CCl4)-treated rats. A total of 60 healthy male Sprague-Dawley rats were utilized in this study. The rats were randomly allotted into one of four experimental groups: A (CCl4-only treated), B (CCl4 + UD treated), C (CCl4 + NS treated) and D (CCl4 + UD + NS treated), each containing 15 animals. All groups received CCl4 [0.8 ml/kg of body weight, subcutaneously, twice a week for 90 days starting day 1]. In addition, B, C and D groups also received daily intraperitoneal injections of 0.2 ml/kg NS or/and 2 ml/kg UD oils for 45 days starting day 46. Group A, on the other hand, received only 2 ml/kg normal saline solution for 45 days starting day 46. Blood samples for the biochemical analysis were taken by cardiac puncture from five randomly chosen rats in each treatment group at beginning, at 45th and at 90th day of the experiment. The CCl4 treatment for 45 days increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatments (alone or combination) for 45 days starting day 46 decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. Live weights of the rats decreased in group A, and increased in groups B, C and D. It is concluded that NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defence system activity in the CCl4-treated rats.

The effects of recombinant LHRH fusion proteins on testicular development and histology in ram lambs

Two recombinant luteinizing hormone releasing hormone (LHRH) fusion proteins were evaluated for their effectiveness in suppression of testicular development and histology by injecting together. Recombinant fusion proteins, ovalbumin-LHRH-7 and thioredoxin-LHRH-7, were generated using recombinant DNA technology and expressed in E. Coli. Eleven ram lambs ranked by age and body weight were randomly assigned to receive either ovalbumin and thioredoxin recombinant protein mixture (control group, n = 5) or ovalbumin-LHRH-7 and thioredoxin-LHRH-7 recombinant fusion protein mixture, anti-LHRH vaccine, (immunization group, n = 6). Animals in each group were weaned at 17 wk of age and were injected (primary immunization) with either mixture at 18 wk of age. Both groups received a booster immunization 8 wks later (26 wk of age). Scrotal circumference, scrotal length, testicular diameter and testicular length were measured in both groups every other week. All animals were slaughtered at 36 wk of age. Immediately after slaughter, a small testicular tissue was taken and processed for histological examination. In the ram lambs in immunization group scrotal circumference and testicular diameter increased steadily until second booster and then remained as a plateau until the end of the experiment. The differences in scrotal circumferences and testicular diameter were significant between the two groups during the last three weeks of the study (p < 0.05). There were no differences in testicular and scrotal length throughout the study (p > 0.05). Seminiferous tubules lost their regular shape and were decreased in diameter in immunization group. Although a few spermatozoa were seen in some tubules, in general, there were atrophy of the seminiferous tubules and loss of spermatogenesis, nevertheless, it seemed that animals in this group were potentially fertile.

Analysis of 16S rRNA and 51-kilodalton antigen gene and transmission in mice of Ehrlichia risticii in virgulate trematodes from Elimia livescens snails in Ohio

Operculate snails (the family Pleuroceridae: Elimia livescens) were collected between June and October 1998 from a river in central Ohio where repeated cases of Potomac horse fever (PHF) have occurred. Of collected snails, consistently 50 to 80% carried a combination of cercariae and sporocysts of digenetic virgulate trematodes. The trematodes obtained from each snail were pooled and tested for Ehrlichia risticii, the agent of PHF, by nested PCR using primers specific to the 16S rRNA gene. Out of a total of 209 trematode pools, 50 pools were found to be positive by PCR. The DNA sequence of the 16S rRNA gene identified in one trematode pool was identical to that of the type strain of E. risticii, and the sequence of the gene identified in another pool differed from that of the type strain by 1 nucleotide. Comparison of the deduced amino acid sequence of the partial 51-kDa antigen gene from various sources revealed that Maryland, Ohio (except Ohio 081), and Kentucky strains are in a cluster distinct from the sequences obtained from sources in California and Oregon. Ohio 081 was shown previously by antigenic composition analysis to be distinct from other groups. However, all sequences examined were not segregated according to their sources: horse blood or infected trematodes. E. risticii was found to be transmittable from trematodes to mice and was subsequently passaged from infected mice to additional mice, as determined by PCR analysis. Our findings suggest the evolution of E. risticii in the natural reservoir in separate geographic regions and persistent infection of trematode populations with E. risticii during summer and early fall. The study also suggests that the mouse can be used to isolate E. risticii from the infected trematode.

Antioxidant content of whole grain breakfast cereals, fruits and vegetables

BACKGROUND

Considerable scientific evidence suggests that whole grains, as commonly consumed in the United States and Europe, reduce risk for chronic disease including cancer and heart disease. Whole grains provide a wide range of nutrients and phytochemicals that may work synergistically to optimize human health. Fruits and vegetables provide protection against age related diseases. It is believed their high content of antioxidant compounds is key to such protection.

OBJECTIVE

This research compares the antioxidant activity of whole grain, ready-to-eat (RTE) breakfast cereals to that of fruits and vegetables.

METHOD

Antioxidant activity was determined by dispersing finely ground samples in a 50% aqueous methanol solution of the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). DPPH, which forms a deep purple solution, reacts with antioxidants and color loss at 515 nm correlates to antioxidant content, which is expressed as Trolox equivalents/100 grams (TE).

RESULTS

Whole grain breakfast cereals analyzed in this study contained from 2,200-3,500 TE. By comparison, fruits generally ranged from 600-1,700 TE, with a high of 2,200 TE for red plums. Berries averaged 3,700 TE and. vegetables averaged 450 TE with a high of 1,400 TE for red cabbage. A 41 gram average serving of RTE breakfast cereal provides 1,120 TE, while an average 85 gram serving of vegetables or fruits provides 380 and 1,020 TE, respectively.

CONCLUSION

Whole grain breakfast cereals, fruits and vegetables are all important dietary sources of antioxidants.

Free radicals, exercise and antioxidant supplementation

Although conflicting data exist, the preponderance of available information suggests that physical exercise promotes an increase in free-radical generation. However, few studies have actually measured exercise-induced free radicals directly, primarily because of a lack of sophisticated methodologies to measure this phenomenon. Instead, researchers have relied heavily on the measurement of lipid peroxidation as the principal indicator of exercise-induced free radicals. It should be noted that free radicals can also alter and inactivate enzyme complexes, damage DNA and RNA, and promote mutations and cancer, among other activities. However, there have been few reported studies dealing with exercise and oxidant stress which have measured these outcomes. It should also be noted that free-radical species are continuously produced in the human body, and that some have beneficial effects (Arouma, 1994), notably as a part of the body's natural immune system. It is not presently known if long-term ingestion of antioxidant compounds will affect these positive aspects of free-radical generation. The preponderance of available evidence suggests that antioxidant supplementation, particularly with the vitamins C and E, has favourable effects on markers of lipid peroxidation following exercise. Although the physiological implications of these effects remain to be elucidated, the prudent use of an antioxidant supplement can provide insurance against a suboptimal diet and/or the elevated demands of physical activity. Future research may uncover additional nutritional antioxidants that can benefit the physically-active individual. Numerous additional questions regarding the antioxidant needs for physical activity remain to be answered. Little is known about the needs of physically-active women, particularly those who habitually consume an energy-restricted diet, or the effects of monthly menstrual blood loss (coupled with exercise) on antioxidant requirements. The needs of the 'weekend warrior' (an individual who participates in strenuous activity sporadically) v. those of the habitual exerciser have not been addressed adequately. The needs of the ageing athlete are largely unknown; a study by Meydani et al. (1993) suggested that elderly, physically-active people can benefit from antioxidant supplementation more than their younger counterparts, but follow-up studies have not been reported to-date. Dietary issues also need to be addressed. How much supplementation is too much, and can chronically-elevated antioxidant intakes have an adverse impact on the positive effects of free radicals in living systems? Does a high-carbohydrate diet raise antioxidant needs, particularly of the fat-soluble vitamin E? Does a high polyunsaturated fat intake, or increased Fe intake affect needs? Obviously, there are a number of issues regarding the antioxidant needs of the physically-active individual that need to be elucidated. Future research utilizing newer, more sophisticated methodologies should provide answers to many of these questions.

Computerized hand diagnostic/rehabilitation system using a force feedback glove

This paper describes recent results of a unified computerized system for hand diagnosis and rehabilitation. Automatic diagnosis data collection and Virtual Reality rehabilitation exercises are the main characteristics of the system. The diagnosis subsystem includes a tactile sensing glove in addition to standard devices such as electronic dynamometer, pinchmeter and goniometer. Three standard rehabilitation exercises were simulated in a Virtual Reality environment, using the WorldToolKit graphics library. The first two exercises (ball squeezing and DigiKey) allow measurement of finger forces exerted during the rehabilitation routine. The third exercise (Peg board) involves the patient's visual-motor coordination. The rehabilitation subsystem uses a VPL DataGlove retrofitted with Rutgers Master (RM-I) and its interface. The exercises involve manipulation of objects with different stiffnesses and geometry. Grasping forces were modeled and fed back using the Rutgers Master worn on patient's hand. Data is gathered in real time from both diagnosis and rehabilitation subsystems. Finger specific forces recorded during rehabilitation exercises allow better diagnosis of the patient impairment. An ORACLE database is used to store and manipulate patients' records. Proof of concept trials were performed in a clinical environment. Some results of patient records analysis are presented in this paper. A new version of the system using an RM II haptic interface is presently under consideration.

Treatment of webbed neck in Turner's syndrome with tissue expansion

We describe a successful approach to the management of the webbed neck deformity in Turner's syndrome using skin expansion. This case report demonstrates the advantages of this method over previously described techniques.

The probability of finding suitable directed donors

A series of tables based on mathematical calculations is given as guidelines for the number of directed donors needed by members of various ethnic/racial groups to provide a desired number of units of blood with a selected probability of achieving this result. From these tables, certain conclusions can be drawn. Unrelated donors who do not know their blood type are an inefficient source of directed donors. Rh-negative patients are unlikely to obtain enough directed-donor units from either related or unrelated donors with confidence unless these donors known their blood type. In general, siblings, parents, and offspring are the most efficient directed donors from the standpoint of compatibility. Cousins, uncles, aunts, nieces, and nephews are not much more likely to be compatible than unrelated donors are. It is easier to obtain suitable directed-donor units among Hispanics than among whites, blacks, or Asians, due to their skewed blood group frequencies. In general, using O-negative directed donors for Rh-positive recipients does not significantly increase the likelihood of finding suitable donors.

Multiple malignant rectal carcinoid tumors with immunocytochemical demonstration of multiple hormonal substances

This case report deals with a patient who presented with 17 small carcinoid tumors of the rectum, the largest measuring less than 1 cm in diameter. After a review of the literature on this subject, this case is believed to be highly unusual in several respects: (1) despite their small size, these tumors resulted in multiple metastases to the regional lymph nodes; (2) both primary tumors and metastases were extensively and strongly argentaffin; and (3) most tumors and metastases contained, when investigated by immunocytochemistry, several biologically active substances such as serotonin, somatostatin, and glucagon-like immunoreactivity.

Spontaneous posterior fossa subdural hematoma as a complication of anticoagulation

We report a patient in whom a spontaneous subdural hematoma developed in the posterior fossa during anticoagulation therapy for mitral valve disease. This rare complication of anticoagulation has been reported in only three other patients.

Several mechanisms can account for defective E alpha gene expression in different mouse haplotypes

The murine Ia antigens, encoded by the I region of the major histocompatibility complex, are cell-surface glyco-proteins (consisting of alpha and beta polypeptides) thought to be involved in the control of immune responsiveness. Mice of haplotypes b, s, q, and f fail to express one of the Ia antigen complexes, the E complex, on the cell surface. We have attempted to determine at the molecular level how such a defect (or defects) might be generated. By using I-region E alpha and A alpha gene probes for analyses of RNA and DNA structure, it was possible to conclude that at least three mechanisms can operate. Mice of haplotypes b and s bear a deletion in the E alpha gene, f haplotype mice synthesize predominantly an E alpha mRNA of aberrant size, and mice of the q haplotype seem to have a defect in RNA processing or a problem with mRNA stability, or both.

Metabolism of exogenous human chorionic gonadotrophin in men

The immunoreactivity of a commercial preparation of human chorionic gonadotrophin (HCG) was determined in a homologous double antibody radioimmunoassay for HCG using antisera to the beta-subunit of the hormone. The immunoreactivity of the commercial HCG was found to be 2.2 +/- 0.3 (mean +/- 2 S.D.) times the biological potency. Exclusion chromatography of the commercial HCG and then curve resolution of the elution profile derived from the radioimmunoassay revealed that on a molar basis, 21% of the immunoreactivity was attributable to beta-HCG. The rate of clearance of this preparation of HCG from the plasma after intravenous administration was determined as a function of the dose administered to ten normal men (age 36--64 years). The doses ranged from 10,000 to 300,000 i.u. immunological potency. The rate of clearance decreased significantly (r = 0.574, P less than 0.05) with increasing doses of HCG from a mean of 786 ml/h at the lowest dose to a mean of 298 ml/h at the highest dose. The renal clearance of administered HCG also decreased with increasing doses; the mean renal clearance of the 10,000 i.u. dose was 3.6 times the mean renal clearance after administration of 200,000 i.u. When the accumulated urinary HCG was expressed as a percentage of the dose administered, 14.1% of the 10,000 i.u. dose and 9.8% of the higher doses accumulated in the urine, suggesting that non-renal clearance increased with increasing dose.