Hormonal deficiency in elderly males

During the aging process, a number of morphological and neurochemical alterations have been found in the supra-chiasmatic nuclei, which are in part responsible for the age-dependent decrease in plasma testosterone (andropause or PADAM), DHEA (adrenopause), GH/IGF-I (somatopause) and melatonin that develops in most men at about the age of 50 (Perry, 1999; Vermeulen et al., 1999). An important principle in antiaging practice is the employment of the best of available means to prevent the preventable and delay the inevitable. Therefore, some scientists advocate multihormonal replacement therapy and the use of antioxidant drugs that may favourably influence some of the pathological conditions in aging men.

Effects of tripchlorolide on the epididymides and testes of rats

AIM

To further evaluate the antifertility effects of tripchlorolide, a derivative of triptolide produced at the extraction procedure of Tripterygium wilfordii Hook. f., in male rats and to investigate its sites and possible mechanisms of action.

METHODS

In male rats, tripchlorolide was given by oral garage at a dose of 50 micrograms.kg-1.d-1 for 5 weeks, fertility was assessed by mating tests, and biochemical indices and light microscopic observation of the epididymides and testes were also performed.

RESULTS

Administration of tripchlorolide at 50 micrograms.kg-1.d-1 for 3 weeks did not influence the fertility of male rats, but 5-week treatment rendered the rats infertile. The density and motility of spermatozoa collected from cauda epididymides were reduced significantly. The epididymal weights, as well as the L-carnitine concentration and alpha-glucosidase content in the epididymal fluid were decreased. There were no significant differences in alpha-glucosidase and acid phosphatase (ACP) in caput epididymal homogenates between the control and the experimental rats. Obvious morphological changes were observed in the epididymal spermatozoa, mainly including head and tail separation or acrosome curving. Sloughed spermatids were found in the seminifeous and epididymal tubules. In testicular homogenates, tripchlorolide had no influence on the lactate dehydrogenase-C4 (LDH-C4) and hyaluronidase activities. No apparent lesions were observed in the seminiferous and epididymal epithelium.

CONCLUSION

At the dose level employed, tripchlorolide has a significant effect on the fertility in male rats and the primary sites of action may be spermatids and testicular and epididymal spermatozoa.

A randomized multicenter study comparing the efficacy and bleeding pattern of a single-rod (Implanon) and a six-capsule (Norplant) hormonal contraceptive implant

To compare the contraceptive efficacy, tolerability, and bleeding patterns, 200 healthy female volunteers received, in an open, comparative, randomized, multicenter study in China, either a single-rod (Implanon) or a six-capsule (Norplant) contraceptive implant for 2 years with an optional extension of up to 4 years. Women were exposed to Implanon for 341.6 woman-years and Norplant for 329.1 woman-years. There were no pregnancies during the study. Per 90-day reference period, the median number of bleeding/spotting days with Implanon decreased from 33.5 in the first period to 19.0-21.5 days in the last year. Similarly, with Norplant, the median number of bleeding/spotting days decreased from 34.5 to 18.0-23.0 days, respectively. The number of bleeding/spotting episodes during year 1 was 2.0 per 90-day reference period with Implanon and 3.0 per period with Norplant (p < 0.05 for periods 1-4). For the remaining 90-day periods, there was no statistical difference between the two groups. In general, there was less frequent bleeding with Implanon compared with Norplant, whereas the incidences of amenorrhea and infrequent bleeding were higher with Implanon than with Norplant. The mean overall incidence of prolonged bleeding fell markedly during the study, from 66.0% in reference period 1 to 27.3% in period 16 with Implanon and from 69.0% to 21.7% with Norplant, respectively. The most common adverse events were related to disturbed bleeding patterns, which were also the major reasons for discontinuation (Implanon n = 8; Norplant n = 14). Normal menses returned in almost all subjects within 3 months after removal of the implants. Implanon was inserted in a mean time of 0.61 min and Norplant in 3.90 min (p < 0.001). Similarly, the mean time required to remove the implant was significantly shorter for Implanon than for Norplant (2.18 min vs 11.25 min, p < 0.001). The maximum time required for removal of the implant was 10 min for the Implanon group and 60 min for the Norplant group. In both groups, blood pressure and hemoglobin were not affected, whereas body weight tended to increase. It can be concluded that both contraceptive systems demonstrated excellent contraceptive efficacy and were well tolerated. Compared with Norplant, there was less frequent bleeding with Implanon, whereas the incidence of infrequent bleeding and amenorrhea was higher. Implanon was significantly quicker to insert and to remove than was the multiple capsule system.

A long-term study of the efficacy and acceptability of a single-rod hormonal contraceptive implant (Implanon) in healthy women in China

OBJECTIVE

To investigate the contraceptive efficacy, cycle control and acceptability of Implanon, a new single-rod, progestogen-only contraceptive implant.

METHODS

In a non-comparative, open, multicenter study, a contraceptive implant containing the progestogen etonogestrel was inserted into 200 healthy women. The study duration was 2 years, with an optional extension up to 4 years.

RESULTS

Women were exposed to Implanon for 644.6 woman-years. There were no pregnancies during the study. Per 90-day reference period, the median number of bleeding-spotting days ranged between 18 and 21 and the median number of bleeding-spotting episodes was two. The mean overall incidence of prolonged bleeding fell markedly during the study, from 69% in the first reference period to 26% in the 16th period. The most common adverse events were related to disturbed bleeding pattern and amenorrhea. Heavy or prolonged bleeding caused 18 subjects to withdraw from the study. Only a few subjects discontinued the study early due to irregular bleeding (2%) or amenorrhea (2%). A slight increase in mean body weight was observed. The implant was removed in an average time of 2.9 min.

CONCLUSIONS

Implanon demonstrated excellent contraceptive efficacy for 4 years of use and was well tolerated. The incidences of prolonged bleeding and amenorrhea both fell markedly with continued implant use. Because of its single-rod design, Implanon was quickly removed with few complications and proved to be a highly acceptable method of contraception.

Effect of intrauterine injection of chlorpromazin on implantation in the rat

In rats, injection of chlorpromazin hydrochloride (CPZ), a calmodulin antagonist, to each uterine horn had a significant (87%) anti-implantation effect and 100% antifertility effect. Both of these rates were zero in the saline control group. Polyacrylamide gel electrophoresis analysis of the uterine fluid showed a decrease in the protein content and certain changes in its chemical composition, in particular, a marked reduction in the number of bands of estradiol-induced 70 kD proteins in the experimental group. No significant difference was found in the ovarian weight and the serum estradiol (E2) and progesterone (P) levels between the two groups. These results suggest that calmodulin influences the process of implantation and this effect is not directly related to the serum concentrations of E2 and P. It is believed that CPZ probably exerted its anti-implantation effect by a direct action on the uterus.

Subcapsular intratesticular assay: a preliminary screening method for putative male antifertility drugs

The subcapsular intratesticular assay was developed for the preliminary screening of male antifertility agents. In the assay, small amounts of the test sample are injected twice, 1 week apart just beneath the tunica albuginea of the testes of rats. The rats were killed within 3 weeks of treatment to examine epididymal spermatozoa and the histology of the testis and epididymis. There is an excellent agreement between this method and the modified MB-50 assay developed by the World Health Organization. To date, more than 300 samples have been assayed, of which the results of 10 plant-derived compounds are reported here. Not one active sample has been missed as confirmed by the modified MB-50 method, although one compound which was positive in the subcapsular assay did not show antifertility action in the in-vivo assay. Compared with the latter assay, the advantages of this method are: simplicity, time-saving, rat-saving and the need for far smaller amounts of test sample. The absence of false-negative results makes the subcapsular intratesticular assay applicable as a preliminary screening method to test potential male fertility regulating agents.

Male antifertility compounds from Tripterygium wilfordii Hook f

Extracts of the Chinese medicinal plant, Tripterygium wilfordii, cause reversible infertility in male animals. Sub-fractionation studies have now revealed that the plant extracts contain a number of compounds which are potent antifertility agents in male mammals, including the diterpenes triptolide and tripdiolide and an isomer of the latter. A triptolide, 12,13-chlorohydrin, which is a transformation product formed reversibly by interaction of triptolide with HCl, was also found to be active.

Infertility in a rural area of Jiangsu Province: an epidemiological survey

Using a random stratified, multistage, and probability sampling procedure, the rate of infertility in the rural area of Jiangsu Province was determined through interviews with 2,578 married women of reproductive age. The overall infertility rate was 5.0%. A significantly higher rate was found for couples in which the husbands were engaged in cotton farming. The study also confirmed the higher infertility rate among smokers found in other studies. The infertility rate was much higher in the Northern Jiangsu Distinct than in the Southern District, suggesting a relationship between infertility and economic/educational conditions.

Study on sperm function in men long after cessation of gossypol treatment

Sperm function was assessed in 19 men 3-10 years after cessation of gossypol treatment and 2-9 years after recovery of normal sperm density. Nineteen normal fertile men of similar age served as the controls. The zona-free hamster egg-sperm penetration assay (SPA) revealed a highly significant difference (P less than 0.01) in the penetration rates between the treated and the control groups. Hormone assays indicated that there were no significant differences in circulating levels of luteinizing hormone (LH) and testosterone (T) between the two groups, but the follicle stimulating hormone (FSH) level of the treated group was significantly higher than that of the controls (P less than 0.05). The results showed that sperm function in the treated group was lower than that in the control, which may be a result of persistent gossypol-mediated damage to the testes.

[Preliminary study on the immune function of red cells in patients with pregnancy-induced hypertension]

This study compared the immune adherent function of red cells, circulating immune complex (CIC) and T lymphocyte immune function in cases of pregnancy induced hypertension (30 cases) and normal pregnancy (30 cases). In the former group the rosette rate of red cells C3b receptor was 8.8 +/- 3.2% (normal rate: 19.4 +/- 6.0%), and rosette rate of E-RFC was 46 +/- 2 +/- 7.3% (normal rate: 62.3 +/- 6.4%). In women with normal pregnancy, the former was 16.9 +/- 4.8%, and the latter was 58.0 +/- 8.3%. In women with pregnancy induced hypertension, the immune adherent function of red cells and T lymphocyte immune function were both lower than those in normal pregnant women, while CIC was higher. In normal pregnant women, the immune adherent function of red cells and T lymphocyte immune function were lower than those in the non-pregnant, while CIC was higher. The mechanism and significance of the red cells immunological adherent function in pregnancy induced hypertension were discussed.

Effects of Tripterygium hypoglaucum (Lévl.) Hutch on male fertility

Tripterygium hypoglaucum (Lévl.) Hutch (TH) is a perennial used in Chinese traditional medicine for the treatment of rheumatoid arthritis and various skin disorders. One study showed that daily oral doses of TH significantly reduced the fertility of male rats without apparent toxicity. The effects of daily oral doses of TH on the fertility of men taking it for the treatment of rheumatoid arthritis were evaluated. Sperm concentration, motility and motility grade all were significantly reduced in the 13 men taking TH compared to 11 untreated controls. TH therapy did not affect testosterone, FSH, LH levels, and its antifertility effects appeared to be reversible.

Recovery of sperm production following the cessation of gossypol treatment: a two-centre study in China

A number of variables were investigated in 46 men who had stopped taking gossypol for their predictive association with the degree and time of recovery of spermatogenesis. Thirty-nine (87%) of the men were azoospermic at cessation of gossypol treatment. In those with sperm present the geometric mean concentration and total sperm count were 8.3 X 10(6)/ml and 30.7 X 10(6), respectively. Twenty-eight men (61%) recovered to a defined threshold of spermatogenic function (sperm concentration greater than or equal to 20 X 10(6)/ml), with a median recovery time of 1.1 years. However, 18 men (39%) had not recovered to this degree of spermatogenic function after a median follow-up of 1.9 years and, of these, 10 (22%) remained azoospermic. The influence of individual baseline variables on the time to defined recovery was examined using Kaplan-Meier curves for groups and their joint effect by Cox's regression model. The failure of recovery was strongly associated with longer treatment, greater total dose of gossypol, smaller testicular volume, elevated FSH concentrations and, to a lesser extent, with greater body weight.

Follow-up of men in the recovery period immediately after the cessation of gossypol treatment

Variables in 46 men who had stopped taking gossypol in two centres in China were investigated for their predictive association with the degree and time of recovery of spermatogenesis. Thirty-nine (87%) were azoospermic at cessation of gossypol treatment. In those with sperm present the geometric mean concentration and total sperm count were 8.3 x 10(6)/ml and 30.7 x 10(6), respectively. Twenty-eight (61%) recovered to a defined threshold spermatogenic function (sperm concentration greater than or equal to 20 x 10(6)/ml), with median recovery time 1.1 years. However, 18 men (39%) had not recovered after a median follow-up of 1.9 years and, of these, 10 (22%) remained azoospermic. The failure of recovery was strongly associated with longer treatment, greater total dose of gossypol, smaller testicular volume, elevated FSH concentrations and, to a lesser extent, with greater body weight.

Tripterygium wilfordii, a Chinese herb effective in male fertility regulation

A refined extract from the root xylem of Tripterygium wilfordii Hook. f. (the so-called multi-glycosides of the plant), available in the market as tablets for the long-term treatment of rheumatoid arthritis and various skin disorders, has recently been shown to possess a powerful antifertility effect in male rats and in men after oral administration at dose levels not showing apparent toxicity or side effects. Fertility appears to be reversible after cessation of treatment. Moreover, preliminary data indicated that the effective antifertility dose in men is only 1/3 of the recommended dose for the treatment of rheumatoid arthritis or skin diseases. This fact supports additional optimism that the side effects of this small dose will be much less as compared with those of the regular dose level. However, a large amount of further investigation is required before one can predict the future of the drug, which seems to hinge upon the successful isolation of the active principle(s) and the careful toxicological evaluation of the safety of the latter. The present paper is a review article summarizing the chemistry, the general pharmacology and the fertility regulatory effect of the plant.

Injection of copper powder into epididymides via vas deferens on male fertility

In adult SD rats, a single injection of silicon rubber containing 10mg metallic copper particles via vas deferens into each cauda epididymis could induce male infertility. Although the copper contact in the cauda epididymides of treated rats was significantly higher than that in the controls, the serum copper concentration did not rise significantly, while the histology of important organs and blood testosterone levels did not change. Treated animals gained weight as fast as the controls, suggesting a low systemic toxicity of this procedure. In 5 of the 8 treated rats, fertility was restored 16 weeks after treatment with normal testicular copper concentration and testicular histology. In 3, fertility was not restored within 16 weeks and the testicular copper concentration was significantly higher than in the controls. Only in these 3 rats were different degrees of damage noted in the seminiferous epithelium and it is anticipated that the fertility will be restored after a certain period of time since sperm production was unaffected. The delayed recovery of fertility in these rats is attributed to the diffusion of copper ions into the testis. It would appear that the injection of silicon rubber containing copper particles via the vas deferens to the cauda epididymides is a potential approach for male contraception.

Effect of Tripterigium wilfordii Hook. f. on the fertility of rats

Studies were undertaken to assess the effect of the total glycosides extracted from Tripterigium wilfordii Hook. f. (GTW), a ready-made Chinese herb medicine, on the fertility of both male and female rats. In male rats, GTW was given by gastric gavage at a dose of 10 mg/kg per day, 6 days a week for 8 weeks. All the treated animals became infertile. The body weight growth was normal and the mating behavior was present. There was a drastic decrease in the viability of the epididymal spermatozoa, while the decrease in the sperm density, though significant, was far less marked. Seminiferous tubular damage was minimal and no perceptible change was observed in the Leydig and the Sertoli cells. All other parameters examined, including the serum testosterone level and the histology of various organs, were normal. In female rats, GTW given orally at a dose of 50 mg/kg per day on days 1-4 or 7-9 of pregnancy did not significantly affect the fertility. It is thus concluded that non-toxic dose of GTW can cause infertility in male rats, the mechanism of which may involve and interference in the function of the epididymal and/or testicular spermatozoa; in female rats, the dose regimens employed do not have significant anti-implantation or early-pregnancy termination effect.

Gossypol-hypokalaemia interrelationships

Around 1% of 8806 volunteers taking gossypol as a male contraceptive had hypokalaemic paralysis and more had simple hypokalaemia, the direct cause being renal potassium loss. In gossypol takers not showing hypokalaemia, serum potassium levels were within the normal range but were significantly lower than levels in controls. In the majority of patients suffering from gossypol-induced hypokalaemia, recovery was prompt and complete following potassium repletion, but in some men there were recurrent attacks of hypokalaemia during a period of several months to years after cessation of gossypol treatment. The incidence of hypokalaemic paralysis in gossypol takers showed distinct regional differences, being much higher in Nanjing, where the dietary potassium level of the inhabitants was low, than in Taian, where the dietary potassium level was high. In rats fed a low-K fodder, gossypol reduced the intracellular Mg and K concentrations of the skeletal muscle, while in regularly fed rats, this effect of gossypol was not observed. A potassium deficient diet could thus be considered a contributing factor in the development of gossypol-induced hypokalaemia. Potassium deficiency has also been shown to enhance the anti-spermatogenic effect of gossypol. Suggested mechanisms for the development of gossypol-induced hypokalaemia include inhibition of Na-K-ATPase activity, stimulation of prostaglandin biosynthesis, damage to the renal tubule, and modification of membrane transport.

Effect of intra-epididymal injection of copper particles on fertility, spermatogenesis, and tissue copper levels in rats

In male rats, a single injection of 10 mg metallic copper particles in oil into each caput epididymidis induced infertility, whilst leaving mating behaviour and blood testosterone levels unchanged. Fertility tended to recover 5.5 months after the copper treatment. Although the copper content of the caput epididymidis reached a level of around 100 times higher than control values, the serum copper concentration did not rise significantly. This finding and the observation that treated animals gained weight as fast as the controls suggest a low systemic toxicity of this method. The testicular copper concentration was significantly higher than that in controls and different degrees of damage, including vacuolation, karyorrhexis, pyknosis, and cytolysis, were seen mainly in pachytene spermatocytes and early spermatids. Clumps of foreign particles, apparently metallic copper, were found in the interstices of the caput epididymidis together with degenerative changes in the epithelial cells of the caput, suggesting a possible effect of copper on the epididymal epithelium. The viability of epididymal sperm decreased more markedly than the decrease in sperm density. It is therefore most likely that the major cause of infertility after copper injection into the caput epididymidis is a direct inhibitory effect of copper on the sperm, whilst damage to the seminiferous and epididymal epithelial may contribute.